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Serine/threonine Kinase (threonine + kinase)
Selected AbstractsDifferential expression pattern of the novel serine/threonine kinase, STK33, in mice and menFEBS JOURNAL, Issue 19 2005Alejandro O. Mujica Serine/threonine kinase 33 (STK33/Stk33) is a recently discovered gene whose inferred amino acid sequence translation displays characters typical for a calcium/calmodulin dependent kinase (CAMK). In this study we analysed the STK33/Stk33 RNA and protein distribution and the localization of the protein. The STK33/Stk33 expression pattern resembles those of some related members of the CAMK group. STK33/Stk33 displays a nonubiquitous and, in most tissues, low level of expression. It is highly expressed in testis, particularly in cells from the spermatogenic epithelia. Moreover, significant expression is detected in lung epithelia, alveolar macrophages, horizontal cells in the retina and in embryonic organs such as heart, brain and spinal cord. A possible role of STK33/Stk33 in spermatogenesis and organ ontogenesis is discussed. [source] Protein kinase C mRNA and protein expressions in hypobaric hypoxia-induced cardiac hypertrophy in ratsACTA PHYSIOLOGICA, Issue 4 2010M. Uenoyama Abstract Aim:, Protein kinase C (PKC), cloned as a serine/threonine kinase, plays key roles in diverse intracellular signalling processes and in cardiovascular remodelling during pressure overload or volume overload. We looked for correlations between changes in PKC isoforms (levels and/or subcellular distributions) and cardiac remodelling during experimental hypobaric hypoxic environment (HHE)-induced pulmonary hypertension. Methods:, To study the PKC system in the heart during HHE, 148 male Wistar rats were housed for up to 21 days in a chamber at the equivalent of 5500 m altitude level (10% O2). Results:, At 14 or more days of exposure to HHE, pulmonary arterial pressure (PAP) was significantly increased. In the right ventricle (RV): (1) the expression of PKC-, protein in the cytosolic and membrane fractions was increased at 3,14 days and at 5,7 days of exposure respectively; (ii) the cytosolic expression of PKC-, protein was increased at 1,5, 14 and 21 days of exposure; (3) the membrane expressions of the proteins were decreased at 14,21 (PKC-,II), 14,21 (PKC-,), and 0.5,5 and 21 (PKC-,) days of exposure; (4) the expression of the active form of PKC-, protein on the plasma membrane was increased at 3 days of exposure (based on semiquantitative analysis of the immunohistochemistry). In the left ventricle, the expressions of the PKC mRNAs, and of their cytosolic and membrane proteins, were almost unchanged. The above changes in PKC-,, which were strongly evident in the RV, occurred alongside the increase in PAP. Conclusion:, PKC-, may help to modulate the right ventricular hypertrophy caused by pulmonary hypertension in HHE. [source] Differential expression pattern of the novel serine/threonine kinase, STK33, in mice and menFEBS JOURNAL, Issue 19 2005Alejandro O. Mujica Serine/threonine kinase 33 (STK33/Stk33) is a recently discovered gene whose inferred amino acid sequence translation displays characters typical for a calcium/calmodulin dependent kinase (CAMK). In this study we analysed the STK33/Stk33 RNA and protein distribution and the localization of the protein. The STK33/Stk33 expression pattern resembles those of some related members of the CAMK group. STK33/Stk33 displays a nonubiquitous and, in most tissues, low level of expression. It is highly expressed in testis, particularly in cells from the spermatogenic epithelia. Moreover, significant expression is detected in lung epithelia, alveolar macrophages, horizontal cells in the retina and in embryonic organs such as heart, brain and spinal cord. A possible role of STK33/Stk33 in spermatogenesis and organ ontogenesis is discussed. [source] A human-specific TNF-responsive promoter for Goodpasture antigen-binding proteinFEBS JOURNAL, Issue 20 2005Froilán Granero The Goodpasture antigen-binding protein, GPBP, is a serine/threonine kinase whose relative expression increases in autoimmune processes. Tumor necrosis factor (TNF) is a pro-inflammatory cytokine implicated in autoimmune pathogenesis. Here we show that COL4A3BP, the gene encoding GPBP, maps head-to-head with POLK, the gene encoding for DNA polymerase kappa (pol ,), and shares with it a 140-bp promoter containing a Sp1 site, a TATA-like element, and a nuclear factor kappa B (NF,B)-like site. These three elements cooperate in the assembly of a bidirectional transcription complex containing abundant Sp1 and little NF,B that is more efficient in the POLK direction. Tumour necrosis factor cell induction is associated with Sp1 release, NF,B recruitment and assembly of a complex comparatively more efficient in the COL4A3BP direction. This is accomplished by competitive binding of Sp1 and NF,B to a DNA element encompassing a NF,B-like site that is pivotal for the 140-bp promoter to function. Consistently, a murine homologous DNA region, which contains the Sp1 site and the TATA-like element but is devoid of the NF,B-like site, does not show transcriptional activity in transient gene expression assays. Our findings identify a human-specific TNF-responsive transcriptional unit that locates GPBP in the signalling cascade of TNF and substantiates previous observations, which independently related TNF and GPBP with human autoimmunity. [source] The centrosomal protein Lats2 is a phosphorylation target of Aurora-A kinaseGENES TO CELLS, Issue 5 2004Shingo Toji Human Lats2, a novel serine/threonine kinase, is a member of the Lats kinase family that includes the Drosophila tumour suppressor lats/warts. Lats1, a counterpart of Lats2, is phosphorylated in mitosis and localized to the mitotic apparatus. However, the regulation, function and intracellular distribution of Lats2 remain unclear. Here, we show that Lats2 is a novel phosphorylation target of Aurora-A kinase. We first showed that the phosphorylated residue of Lats2 is S83 in vitro. Antibody that recognizes this phosphorylated S83 indicated that the phosphorylation also occurs in vivo. We found that Lats2 transiently interacts with Aurora-A, and that Lats2 and Aurora-A co-localize at the centrosomes during the cell cycle. Furthermore, we showed that the inhibition of Aurora-A-induced phosphorylation of S83 on Lats2 partially perturbed its centrosomal localization. On the basis of these observations, we conclude that S83 of Lats2 is a phosphorylation target of Aurora-A and this phosphorylation plays a role of the centrosomal localization of Lats2. [source] Modulation of p21-activated kinase 1 alters the behavior of renal cell carcinomaINTERNATIONAL JOURNAL OF CANCER, Issue 9 2007Gerald C. O'Sullivan Abstract The p21-activated kinase 1 (Pak1) is a serine/threonine kinase whose activity is regulated by both Rho GTPases and AGC kinase family members. It plays a role in cytoskeletal remodeling and cell motility as well as cell proliferation, angiogenesis, tumorigenesis and metastasis. An involvement of Pak1 in renal cell carcinoma (RCC), which remains highly refractory to chemotherapy and radiotherapy, remains to be investigated. Pak1 expression, phosphorylation and kinase activity were examined in RCC cell lines and human tissue from normal and renal carcinoma. We report increased Pak1 expression and constitutive activity in the membrane and nucleus but not the cytoplasm of resected human RCC. To study a role for Pak1 in RCC, we developed 786-0 clones that expressed either a kinase-active Pak1L83,L86 2 different Pak1 dominant negative mutants, Pak1R299 and Pak1L83,L86,R299 or Pak1 siRNA. The expression of Pak1L83,L86 increased 786-0 proliferation, motility and anchorage independent growth, while the dominant negative mutants and Pak1 siRNA abrogated these effects. In addition, Pak1L83,L86 conferred resistance to 5-fluorouracil with a 40% ± 10% increase in cell viability. Conversely, Pak1L83,L86,R299, Pak1R299 and Pak1 siRNA conferred sensitivity with a 65.2% ± 5.5%, 69.2% ± 3.3% and 73.0% ± 8.4% loss in viability, respectively. Finally, Pak1 plays a role in renal tumor growth in vivo. Only 33% of mice developed tumors in the Pak1L83,L86,R299 group and no tumors developed from Pak1R299 cell challenge. Together these findings point to Pak1 as an exciting target for therapy of renal cancer, which remains highly refractory to existing treatments. © 2007 Wiley-Liss, Inc. [source] Akt is frequently activated in HER2/neu-positive breast cancers and associated with poor prognosis among hormone-treated patientsINTERNATIONAL JOURNAL OF CANCER, Issue 2 2006Eriko Tokunaga Abstract Akt/PKB is a serine/threonine kinase that plays an important role in survival when cells are exposed to different apoptotic stimuli. Aberrant activation of Akt/PKB in breast carcinoma is associated with poor prognosis and resistance to endocrine therapy and chemotherapy. The Akt signaling pathway currently attracts considerable attention as a new target for effective therapeutic strategies. We therefore investigated the relationship between activation of Akt and clinicopathologic variables including hormone receptor and HER2/neu status. Breast cancer tissues obtained from 252 patients were utilized for this study. We evaluated Akt activation by immunohistochemical assessment of the expression of phosphorylated Akt (pAkt) at Ser-473. Eighty-four cases (33.3%) were diagnosed as positive for pAkt expression. pAkt was significantly associated with HER2/neu overexpression (p < 0.0001). There was an inverse correlation between pAkt and PR expression (p = 0.0321); however, there was no association between pAkt and ER expression. Survival analysis showed that pAkt positivity was associated with poor disease-free survival in cases with postoperative hormone therapy; however, there was no association in cases without hormone therapy. Our results indicate that Akt activation induced poor prognosis in patients who received adjuvant hormone therapy. This finding suggests that inhibition of the Akt signaling pathway may increase the efficacy of hormone therapy and improve the prognosis of patients who receive adjuvant hormone therapy. © 2005 Wiley-Liss, Inc. [source] Role of estrogenic compounds (diethylstibestrol, 17,-estradiol, and bisphenol A) in the phosphorylation of substrate by protein kinase C,JOURNAL OF BIOCHEMICAL AND MOLECULAR TOXICOLOGY, Issue 5 2009Jeong-Hun Kang Abstract Estrogenic compounds can activate protein kinase C (PKC), which is a calcium and phospholipid-dependent serine/threonine kinase. In the present study, we investigated the role of 17,-estradiol (E2), diethylstibestrol (DES), and bisphenol A (BPA) in the phosphorylation of substrate by PKC, using the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The level of phosphorylated peptide was low in the absence of phosphatidylserine (PS). Moreover, reduction of phosphorylation ratios was identified in the presence of diacylglycerol (DAG) and Ca2+ or PS and Ca2+ after adding E2, DES, and BPA. However, no change in phosphorylation ratios was found in the presence of DAG and PS. Addition of E2, DES, and BPA also had no influence on the phosphorylation reaction of substrate by cell or tissue lysate samples. Our study suggests that E2, DES, and BPA can bind to the C2 domain of PKC, but have no effects on the phosphorylation reaction of substrates in the presence of DAG and PS. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:318,323, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20294 [source] Cyclin-dependent kinase 5 in synaptic plasticity, learning and memoryJOURNAL OF NEUROCHEMISTRY, Issue 2 2006Marco Angelo Abstract Cyclin-dependent kinase 5 (Cdk5) is a serine/threonine kinase with a multitude of functions. Although Cdk5 is widely expressed, it has been studied most extensively in neurons. Since its initial characterization, the fundamental contribution of Cdk5 to an impressive range of neuronal processes has become clear. These phenomena include neural development, dopaminergic function and neurodegeneration. Data from different fields have recently converged to provide evidence for the participation of Cdk5 in synaptic plasticity, learning and memory. In this review, we consider recent data implicating Cdk5 in molecular and cellular mechanisms underlying synaptic plasticity. We relate these findings to its emerging role in learning and memory. Particular attention is paid to the activation of Cdk5 by p25, which enhances hippocampal synaptic plasticity and memory, and suggests formation of p25 as a physiological process regulating synaptic plasticity and memory. [source] Molecular activity of sirolimus and its possible application in tuberous sclerosis treatmentMEDICINAL RESEARCH REVIEWS, Issue 2 2006Jaroslaw Jozwiak Abstract Sirolimus is one of the intensively investigated drugs with pluripotent activities. It binds to its intracellular receptor FKBP12 (FK506-binding protein 12), a member of the family of FK506-binding proteins, and inhibits the activity of mTOR, a serine/threonine kinase involved in numerous cell processes linked to cell growth control. The drug is currently registered for the prophylaxis of organ rejection and for use in coronary stents. However, unique characteristics of sirolimus make it a good candidate for anti-cancer therapy. Indeed, phase II and III clinical studies in humans with several types of neoplasms are already under way. The review describes molecular activity of sirolimus and its analogs, characteristic for specific applications, in view of very recent advances involving tuberous sclerosis complex (TSC)-mediated signaling pathways. Current studies with sirolimus performed in tuberous sclerosis animal models are presented. Possible application of sirolimus for treating tuberous sclerosis, disease caused by mutations of TSC proteins, is discussed. © 2005 Wiley Periodicals, Inc. Med Res Rev [source] Threonine phosphorylation prevents promoter DNA binding of the Group B Streptococcus response regulator CovRMOLECULAR MICROBIOLOGY, Issue 6 2009Wan-Jung Lin Summary All living organisms communicate with the external environment for their survival and existence. In prokaryotes, communication is achieved by two-component systems (TCS) comprising histidine kinases and response regulators. In eukaryotes, signalling is accomplished by serine/threonine and tyrosine kinases. Although TCS and serine/threonine kinases coexist in prokaryotes, direct cross-talk between these families was first described in Group B Streptococcus (GBS). A serine/threonine kinase (Stk1) and a TCS (CovR/CovS) co-regulate toxin expression in GBS. Typically, promoter binding of regulators like CovR is controlled by phosphorylation of the conserved active site aspartate (D53). In this study, we show that Stk1 phosphorylates CovR at threonine 65. The functional consequence of threonine phosphorylation of CovR in GBS was evaluated using phosphomimetic and silencing substitutions. GBS encoding the phosphomimetic T65E allele are deficient for CovR regulation unlike strains encoding the non-phosphorylated T65A allele. Further, compared with wild-type or T65A CovR, the T65E CovR is unable to bind promoter DNA and is decreased for phosphorylation at D53, similar to Stk1-phosphorylated CovR. Collectively, we provide evidence for a novel mechanism of response regulator control that enables GBS (and possibly other prokaryotes) to fine-tune gene expression for environmental adaptation. [source] Regulation of purine biosynthesis by a eukaryotic-type kinase in Streptococcus agalactiaeMOLECULAR MICROBIOLOGY, Issue 5 2005Lakshmi Rajagopal Summary Group B streptococci (GBS) are the principal causal agents of human neonatal pneumonia, sepsis and meningitis. We had previously described the existence of a eukaryotic-type serine/threonine kinase (Stk1) and phosphatase (Stp1) in GBS that regulate growth and virulence of the pathogen. Our previous results also demonstrated that these enzymes reversibly phosphorylated an inorganic pyrophosphatase. To understand the role of these eukaryotic-type enzymes on growth of GBS, we assessed the stk1 -mutants for auxotrophic requirements. In this report, we describe that in the absence of the kinase (Stk1), GBS are attenuated for de novo purine biosynthesis and are consequently growth arrested. During growth in media lacking purines, the intracellular G nucleotide pools (GTP, GDP and GMP) are significantly reduced in the Stk1-deficient strains, while levels of A nucleotides (ATP, ADP and AMP) are marginally increased when compared with the isogenic wild-type strain., We, provide, evidence, that, the, reduced, pools of, G, nucleotides, result, from, altered, activity, of, the IMP utilizing enzymes, adenylosuccinate synthetase (PurA) and IMP dehydrogenase (GuaB) in these strains. We also demonstrate that Stk1 and Stp1 reversibly phosphorylate and consequently regulate PurA activity in GBS. Collectively, these data indicate the novel role of eukaryotic-type kinases in regulation of metabolic processes such as purine biosynthesis. [source] Haspin-like proteins: A new family of evolutionarily conserved putative eukaryotic protein kinasesPROTEIN SCIENCE, Issue 8 2001Jonathan M.G. Higgins Abstract Haspin (haploid germ cell,specific nuclear protein kinase) is reported to be a serine/threonine kinase that may play a role in cell-cycle cessation and differentiation of haploid germ cells. In addition, Haspin mRNA can be detected in diploid cell lines and tissues. Here, Haspin-like proteins are identified in several major eukaryotic phyla,including yeasts, plants, flies, fish, and mammals,and an extended group in Caenorhabditis elegans. The Haspin-like proteins have a complete but divergent eukaryotic protein kinase domain sequence. Although clearly related to one another and to other eukaryotic protein kinases, the Haspin-related proteins lack conservation of a subset of residues that are almost invariant in known kinases and possess distinctive inserted regions. In fact, phylogenetic analysis indicates that the Haspin-like proteins form a novel eukaryotic protein kinase family distinct from those previously defined. The identification of related proteins in model organisms provides some initial insight into their functional properties and will provide new experimental avenues by which to determine the function of the Haspin proteins in mammalian cells. [source] Identification of differentially expressed proteins in papillary thyroid carcinomas with V600E mutation of BRAFPROTEOMICS - CLINICAL APPLICATIONS, Issue 7 2007Efisio Puxeddu Abstract BRAF, a serine/threonine kinase of the RAF family, is a downstream transducer of the RAS-regulated MAPK pathway. V600E mutation of BRAF protein is the most common genetic alteration occurring in papillary thyroid carcinomas and is prognostic of poor clinicopathological outcomes. Protein expression in the subclass of PTC bearing the BRAFV600E mutation was investigated by using 2-DE and MS/MS techniques and compared to that of matched normal thyroid tissues from seven patients. 2-D gel image analysis revealed that the expression of eight polypeptide spots, corresponding to five proteins, were significantly underexpressed in PTC bearing BRAFV600E mutation whereas 25 polypeptides, representing 19 distinct proteins, were significantly upregulated in tumour tissue, as compared to normal thyroid. Among the differentially expressed polypeptides, mitochondrial proteins, ROS-scavenger enzymes, apoptosis-related proteins as well as proteins involved in tumour cell proliferation were identified. Although dissimilarities between the present results and those previously reported can be ascribed to the use of different 2-DE techniques, the possibility that BRAFV600E mutation is responsible for changes in protein expression distinct from those induced by other oncogenes cannot be ruled out. [source] Signal transduction by G-proteins, Rho-kinase and protein phosphatase to smooth muscle and non-muscle myosin IITHE JOURNAL OF PHYSIOLOGY, Issue 2 2000Andrew P. Somlyo We here review mechanisms that can regulate the activity of myosin II, in smooth muscle and non-muscle cells, by modulating the Ca2+ sensitivity of myosin regulatory light chain (RLC) phosphorylation. The major mechanism of Ca2+ sensitization of smooth muscle contraction and non-muscle cell motility is through inhibition of the smooth muscle myosin phosphatase (MLCP) that dephosphorylates the RLC in smooth muscle and non-muscle. The active, GTP-bound form of the small GTPase RhoA activates a serine/threonine kinase, Rho-kinase, that phosphorylates the regulatory subunit of MLCP and inhibits phosphatase activity. G-protein-coupled release of arachidonic acid may also contribute to inhibition of MLCP acting, at least in part, through the Rho/Rho-kinase pathway. Protein kinase C(s) activated by phorbol esters and diacylglycerol can also inhibit MLCP by phosphorylating and thereby activating CPI-17, an inhibitor of its catalytic subunit; this mechanism is independent of the Rho/Rho-kinase pathway and plays only a minor, transient role in the G-protein-coupled mechanism of Ca2+ sensitization. Ca2+ sensitization by the Rho/Rho-kinase pathway contributes to the tonic phase of agonist-induced contraction in smooth muscle, and abnormally increased activation of myosin II by this mechanism is thought to play a role in diseases such as high blood pressure and cancer cell metastasis. [source] Emergence of protein kinase CK2 as a key target in cancer therapyBIOFACTORS, Issue 3 2010Janeen H. Trembley Abstract Protein kinase CK2, a protein serine/threonine kinase, plays a global role in activities related to cell growth, cell death, and cell survival. CK2 has a large number of potential substrates localized in diverse locations in the cell including, for example, NF-,B as an important downstream target of the kinase. In addition to its involvement in cell growth and proliferation it is also a potent suppressor of apoptosis, raising its key importance in cancer cell phenotype. CK2 interacts with diverse pathways which illustrates the breadth of its impact on the cellular machinery of both cell growth and cell death giving it the status of a "master regulator" in the cell. With respect to cancer, CK2 has been found to be dysregulated in all cancers examined demonstrating increased protein expression levels and nuclear localization in cancer cells compared with their normal counterparts. We originally proposed CK2 as a potentially important target for cancer therapy. Given the ubiquitous and essential for cell survival nature of the kinase, an important consideration would be to target it specifically in cancer cells while sparing normal cells. Towards that end, our design of a tenascin based sub-50 nm (i.e., less than 50 nm size) nanocapsule in which an anti-CK2 therapeutic agent can be packaged is highly promising because this formulation can specifically deliver the cargo intracellularly to the cancer cells in vivo. Thus, appropriate strategies to target CK2 especially by molecular approaches may lead to a highly feasible and effective approach to eradication of a given cancer. [source] Crystallization and initial X-ray diffraction study of the three PASTA domains of the Ser/Thr kinase Stk1 from the human pathogen Staphylococcus aureusACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2009Patricia Paracuellos PASTA subunits (,70 amino acids) are specific to bacterial serine/threonine kinases and to penicillin-binding proteins (PBPs) and are involved in the synthesis of peptidoglycan. The human pathogen Staphylococcus aureus contains a serine/threonine kinase, Stk1, which plays a major role in virulence. A recombinant His-tagged portion of the extracellular domain of Stk1 containing three PASTA subunits has been crystallized using zinc sulfate as a crystallizing agent. The crystals belonged to the tetragonal space group P4122, with unit-cell parameters a = 68.0, b = 68.0, c = 158.1,Å. Structure determination by the MAD method is now in progress. [source] Crystallization and preliminary X-ray diffraction analysis of motif N from Saccharomyces cerevisiae Dbf4ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 9 2009Lindsay A. Matthews The Cdc7,Dbf4 complex plays an instrumental role in the initiation of DNA replication and is a target of replication-checkpoint responses in Saccharomyces cerevisiae. Cdc7 is a conserved serine/threonine kinase whose activity depends on association with its regulatory subunit, Dbf4. A conserved sequence near the N-terminus of Dbf4 (motif N) is necessary for the interaction of Cdc7,Dbf4 with the checkpoint kinase Rad53. To understand the role of the Cdc7,Dbf4 complex in checkpoint responses, a fragment of Saccharomyces cerevisiae Dbf4 encompassing motif N was isolated, overproduced and crystallized. A complete native data set was collected at 100,K from crystals that diffracted X-rays to 2.75,Å resolution and structure determination is currently under way. [source] Structure of human protein kinase CK2,2 with a potent indazole-derivative inhibitorACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 2 2009Tetsuko Nakaniwa Casein kinase 2 (CK2) is a serine/threonine kinase that functions as a heterotetramer composed of two catalytic subunits (CK2,1 or CK2,2) and two regulatory subunits (CK2,). The two isozymes CK2,1 and CK2,2 play distinguishable roles in healthy subjects and in patients with diseases such as cancer, respectively. In order to develop novel CK2,1-selective inhibitors, the crystal structure of human CK2,2 (hCK2,2) complexed with a potent CK2, inhibitor which binds to the active site of hCK2,2 was determined and compared with that of human CK2,1. While the two isozymes exhibited a high similarity with regard to the active site, the largest structural difference between the isoforms occurred in the ,4,,5 loop responsible for the CK2,,CK2, interface. The top of the N-terminal segment interacted with the ,4,,5 loop via a hydrogen bond in hCK2,2 but not in hCK2,1. Thus, the CK2,,CK2, interface is a likely target candidate for the production of selective CK2,1 inhibitors. [source] GSK3,: role in therapeutic landscape and development of modulatorsBRITISH JOURNAL OF PHARMACOLOGY, Issue 1 2010S Phukan Glycogen synthase kinase-3 beta (GSK3,) is a multifunctional serine/threonine kinase which was originally identified as a regulator of glycogen metabolism. It plays a key role in the regulation of numerous signalling pathways including cellular process such as cell cycle, inflammation and cell proliferation. Over the last few years there is a considerable rise in the number of journals and patents publication by different workers worldwide. Many pharmaceutical companies are focusing on GSK3, as a therapeutic target for the treatment of disease conditions. The present review is focused on signalling pathways of different disease conditions where GSK3, is implicated. In this review, we present a comprehensive map of GSK3, signalling pathways in disease physiologies. Structural analysis of GSK3, along with molecular modelling reports from numerous workers are reviewed in context of design and development of GSK3, inhibitors. Patent landscape of the small molecule modulators is profiled. The chemo space for small molecule modulators extracted from public and proprietary Kinase Chembiobase for GSK3, are discussed. Compounds in different clinical phases of discovery are analysed. The review ends with the overall status of this important therapeutic target and challenges in development of its modulators. [source] Protein kinase E of Mycobacterium tuberculosis has a role in the nitric oxide stress response and apoptosis in a human macrophage model of infectionCELLULAR MICROBIOLOGY, Issue 2 2008Deepak Jayakumar Summary Mycobacterium tuberculosis, an intracellular pathogen, inhibits macrophage apoptosis to support survival and replication inside the host cell. We provide evidence that the functional serine/threonine kinase, PknE, is important for survival of M. tuberculosis that enhances macrophage viability by inhibiting apoptosis. A promoter of PknE identified in this study was shown to respond to nitric oxide stress. Deletion of pknE in virulent M. tuberculosis, H37Rv, resulted in a strain that has increased resistance to nitric oxide donors and increased sensitivity to reducing agents. The deletion mutant created by specialized transduction induced enhanced apoptosis while inhibiting necrosis. The pknE mutant also modifies the innate immune response as shown by the marked decline in the pro-inflammatory cytokines in a macrophage model of infection. These findings suggest a novel mechanism, by which PknE senses nitric oxide stress and prevents apoptosis by interfering with host signalling pathways. [source] Helicobacter pylori activates protein kinase C delta to control Raf in MAP kinase signalling: Role in AGS epithelial cell scattering and elongationCYTOSKELETON, Issue 10 2009Sabine Brandt Abstract Helicobacter pylori is a major etiological agent in the development of chronic gastritis, duodenal ulcer and gastric carcinoma in humans. Virulent H. pylori strains harbor a type IV secretion system (T4SS) encoded by the cag pathogenicity island. This T4SS injects the CagA protein into gastric epithelial cells leading to actin-cytoskeletal rearrangements followed by cell elongation and scattering. Here we report that PMA (4,-phorbol-12-myristate-13-acetate), a well-known cell-permeable activator of protein kinase C (PKC), induces a remarkably similar cellular phenotype as compared to infection with H. pylori. PKCs comprise a large family of serine/threonine kinases which are important for multiple physiological processes of host cells. We therefore investigated the role of individual PKC members and the signalling pathways involved in phenotypical outcome. Using isoform-specific silencing RNAs and pharmacological inhibitors we found that two isoforms, PKC-, and PKC-,, were essential for both PMA- and H. pylori -induced elongation phenotype. Furthermore, we provide evidence that PKC-, activity is profoundly stimulated during the course of infection using activation-specific antibodies against PKC phosphorylated at threonine residue 505 or serine residue 660. Infection with H. pylori wild-type and mutants showed that at least two bacterial factors activate PKC-, in a time-dependent manner, one of which is CagA. Immunofluorescence microscopy studies further demonstrated that phosphorylated PKC-, is accumulated and recruited to dynamic actin-structures at the cell membrane. Finally, we show that PKC-, specifically targets Raf kinase to stimulate the Erk1/2 kinase pathway, which is also crucial for phenotypical outcome. Thus, PKC-, is another important mediator of H. pylori -induced pathogenesis. Cell Motil. Cytoskeleton 2009. © 2009 Wiley-Liss, Inc. [source] Bacterial protein kinase inhibitorsDRUG DEVELOPMENT RESEARCH, Issue 3 2010Michio Kurosu Abstract Protein kinases have become the second most important group of drug targets for the pharmaceutical industry next to G-protein-coupled receptors. Thus, over the past decade, a significant number of small molecules have been generated for protein kinase drug optimization programs. The vast majority of kinase inhibitors target the ATP binding site of the enzyme; however, the poor protein kinase selectivity of ATP-competitive protein kinase inhibitors (PKIs) limits their use for treating chronic diseases. In contrast, for inhibitors of bacterial signal transduction systems targeting bacterial kinase(s), there are no such selectivity requirements as long as the inhibitor does not act on any human kinases at the effective concentrations for killing bacteria in vivo. Protein phosphorylation in bacteria is performed by two-component signal transduction systems (2CSTSs) and eukaryotic-like serine/threonine kinases or bacterial tyrosine kinases. Recently, a large number of studies of protein kinases essential for sustaining bacterial growth and kinases required for virulence have been reported. Thus, bacterial protein kinases offer considerable potential as new drug targets. To identify bacterial PKIs, large chemical libraries of ATP-competitive inhibitors developed for eukaryotic protein kinases are an invaluable asset. This manuscript reviews progress on the development of prokaryotic protein kinase inhibitors. Drug Dev Res 2010. © 2010 Wiley-Liss, Inc. [source] Regulation of MC1R signalling by G-protein-coupled receptor kinasesEXPERIMENTAL DERMATOLOGY, Issue 9 2004J. C. García-Borrón The melanocortin 1 receptor (MC1R) is a key regulator of melanocyte proliferation and differentiation and a major determinant of human skin phototype and skin cancer risk. Although the regulation of MC1R gene expression is fairly well understood, little is known about regulatory mechanisms acting at the protein level. In particular, no information is available on homologous desensitization of MC1R signalling. We studied MC1R and Mc1r desensitization and found that: 1) MC1R and Mc1r in melanoma cells undergo homologous desensitization, demonstrated by decreases in cAMP contents upon continuous exposure to agonists, 2) desensitization is not dependent on PKA, PKC, calcium mobilization or MAPKs but is agonist dose dependent, suggesting a role of receptor occupancy, 3) melanoma cells express two members of the GRK family of serine/threonine kinases, GRK2 and GRK6, 4. These kinases are expressed in normal melanocytes, 5) in cotransfection experiments performed with HEK 293T cells, GRK2 strongly impairs agonist-dependent signalling by MC1R or Mc1r, 6) expression of a dominant negative GRK2 mutant in melanoma cells increases their cAMP response to MC1R agonists, 7) cotransfection of HEK 293T cells with GRK6 and MC1R inhibits both basal and agonist-dependent signalling, and 8) cAMP production in agonist-stimulated melanoma cells is strongly impaired by enrichment with GRK6 following stable transfection. Therefore, GRK2 and GRK6 are key regulators of MC1R signalling and may be important determinants of normal and pathological skin pigmentation. [source] Smad3 as a mediator of the fibrotic responseINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 2 2004Kathleen C. Flanders Summary Transforming growth factor-, (TGF-,) plays a central role in fibrosis, contributing to the influx and activation of inflammatory cells, the epithelial to mesenchymal transdifferentiation (EMT) of cells and the influx of fibroblasts and their subsequent elaboration of extracellular matrix. TGF-, signals through transmembrane receptor serine/threonine kinases to activate novel signalling intermediates called Smad proteins, which modulate the transcription of target genes. The use of mice with a targeted deletion of Smad3, one of the two homologous proteins which signals from TGF-,/activin, shows that most of the pro-fibrotic activities of TGF-, are mediated by Smad3. Smad3 null inflammatory cells and fibroblasts do not respond to the chemotactic effects of TGF-, and do not autoinduce TGF-,. The loss of Smad3 also interferes with TGF-,-mediated induction of EMT and genes for collagens, plasminogen activator inhibitor-1 and the tissue inhibitor of metalloprotease-1. Smad3 null mice are resistant to radiation-induced cutaneous fibrosis, bleomycin-induced pulmonary fibrosis, carbon tetrachloride-induced hepatic fibrosis as well as glomerular fibrosis induced by induction of type 1 diabetes with streptozotocin. In fibrotic conditions that are induced by EMT, such as proliferative vitreoretinopathy, ocular capsule injury and glomerulosclerosis resulting from unilateral ureteral obstruction, Smad3 null mice also show an abrogated fibrotic response. Animal models of scleroderma, cystic fibrosis and cirrhosis implicate involvement of Smad3 in the observed fibrosis. Additionally, inhibition of Smad3 by overexpression of the inhibitory Smad7 protein or by treatment with the small molecule, halofuginone, dramatically reduces responses in animal models of kidney, lung, liver and radiation-induced fibrosis. Small moleucule inhibitors of Smad3 may have tremendous clinical potential in the treatment of pathological fibrotic diseases. [source] Casein Kinase I: From Obscurity to Center StageIUBMB LIFE, Issue 2 2001Erica Vielhaber Abstract The casein kinase I (CKI) family of protein kinases is a group of highly related, ubiquitously expressed serine/threonine kinases found in all eukaryotic organisms from protozoa to man. Recent advances in diverse fields, including developmental biology and chronobiology, have elucidated roles for CKI in regulating critical processes such as Wnt signaling, circadian rhythm, nuclear import, and Alzheimer's disease progression. [source] Intracellular signaling involved in macrophage adhesion and FBGC formation as mediated by ligand,substrate interactionJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 4 2002Weiyuan John Kao Abstract Fibronectin and RGD- and/or PHSRN-containing oligopeptides were preadsorbed onto physicochemically distinct substrata: polyethyleneglycol-based networks or tissue culture polystyrene (TCPS). The role of selected signaling kinases (namely protein tyrosine kinases, protein serine/threonine kinases, PI3-kinase, Src, and MAPK) in the adhesion of human primary blood-derived macrophages and the formation of foreign-body giant cells (FBGC) on these modified substrata was investigated. The involvement of individual intracellular signaling molecules in mediating macrophage adhesion dynamically varied with the culture time, substrate, and ligand. For example, fibronectin on TCPS or networks involved similar signaling events for macrophage adhesion; however, fibronectin and G3RGDG6PHSRNG, but not peptides with other RGD and/or PHSRN orientations, mediated similar signaling events for macrophage adhesion on TCPS but mediated different signaling events on networks. Depending on the substrate, a specific molecule (i.e., Src, protein kinase C) within the protein tyrosine kinase or protein serine/threonine kinase family was either an antagonist or agonist in mediating FBGC formation. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 478,487, 2002 [source] Mirk/Dyrk1B in cancerJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2007Eileen Friedman Abstract Mirk/Dyrk1B is a member of a conserved family of serine/threonine kinases which are activated by intramolecular tyrosine phosphorylation, and which mediate differentiation in different tissues,Mirk in skeletal muscle, Dyrk1A in the brain, etc. One role of Mirk in skeletal muscle differentiation is to block cycling myoblasts in the G0 quiescent state by modification of cell cycle regulators, while another role of Mirk is to limit apoptosis in fusing myoblasts. Amplification of the Mirk gene, upregulation of Mirk expression and/or constitutive activation of this kinase have been observed in several different types of cancer. If coupled with a stress condition such as serum starvation which induces a quiescent state, depletion of Mirk by RNA interference using either synthetic duplex RNAi's or pSilencer-encoded RNAi's have decreased colony formation of different cancer cell lines and enhanced apoptosis induced by chemotherapeutic drugs. Mirk is activated by phosphorylation by the stress-activated SAPK kinases MKK3 and MKK6. Our working hypothesis is that Mirk is activated by this pathway in response to various stresses, and then acts as a checkpoint kinase to arrest damaged tumor cells in a quiescent state and allow cellular repair. Pharmacological inhibition of Mirk may enhance the anti-tumor effect of chemotherapeutic drugs. J. Cell. Biochem. 102: 274,279, 2007. © 2007 Wiley-Liss, Inc. [source] c-Jun Expression, activation and function in neural cell death, inflammation and repairJOURNAL OF NEUROCHEMISTRY, Issue 4 2008Gennadij Raivich Abstract Up-regulation of c-Jun is a common event in the developing, adult as well as in injured nervous system that serves as a model of transcriptional control of brain function. Functional studies employing in vivo strategies using gene deletion, targeted expression of dominant negative isoforms and pharmacological inhibitors all suggest a three pronged role of c-Jun action, exercising control over neural cell death and degeneration, in gliosis and inflammation as well as in plasticity and repair. In vitro, structural and molecular studies reveal several non-overlapping activation cascades via N-terminal c-Jun phosphorylation at serine 63 and 73 (Ser63, Ser73), and threonine 91 and 93 (Thr91, Thr93) residues, the dephosphorylation at Thr239, the p300-mediated lysine acetylation of the near C-terminal region (Lys268, Lys271, Lys 273), as well as the Jun-independent activities of the Jun N-terminal family of serine/threonine kinases, that regulate the different and disparate cellular responses. A better understanding of these non-overlapping roles in vivo could considerably increase the potential of pharmacological agents to improve neurological outcome following trauma, neonatal encephalopathy and stroke, as well as in neurodegenerative disease. [source] Role of mitogen-activated protein kinases in phenethyl isothiocyanate-induced apoptosis in human prostate cancer cellsMOLECULAR CARCINOGENESIS, Issue 3 2005Dong Xiao Abstract The present study was undertaken to examine the role of mitogen-activated protein kinases (MAPKs) in apoptosis induction by phenethyl isothiocyanate (PEITC), a cruciferous vegetable-derived cancer chemopreventive agent, with DU145 and LNCaP human prostate cancer cells as a model. The MAPK family of serine/threonine kinases, including extracellular signal-regulated kinase1/2 (ERK1/2), c- jun N-terminal kinase1/2/3 (JNK1/2/3), and p38 MAPK play an important role in cell proliferation and apoptosis in response to different stimuli. Exposure of DU145 and LNCaP cells to growth suppressive concentrations of PEITC resulted in activation of ERK1/2 and JNKs, but not p38 MAPK, in both cell lines. In DU145 cells, the apoptosis induction by PEITC was statistically significantly attenuated by pharmacological inhibition of JNKs with SP600125. Adenovirus-mediated overexpression of Flag-tagged JNK binding domain (JBD) of JNK-interacting protein-1 (JIP-1), an inhibitor of JNK, also inhibited PEITC-induced apoptosis in DU145 cells. On the other hand, inhibition of ERK1/2 activation with MEK1 inhibitor PD98059 failed to offer protection against PEITC-induced apoptosis in DU145 cells. In LNCaP cells, the PEITC-induced cell death was not affected by either pretreatment with PD98059 or SP600125 or overexpression of JBD of JIP-1. These results indicate that involvement of MAPKs in apoptosis induction by PEITC in human prostate cancer cells is cell line-specific. © 2005 Wiley-Liss, Inc. [source] | ||||||||||||||||