Home About us Contact
|
Home About us Contact | ||
|
|
||
Transcriptional Regulatory Protein (transcriptional + regulatory_protein)
Selected Abstracts2,3,7,8-Tetrachlorodibenzo- p -dioxin modifies expression and nuclear/cytosolic localization of bovine herpesvirus 1 immediate-early protein (bICP0) during infectionJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 2 2010Filomena Fiorito Abstract Our previous studies have demonstrated that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases Bovine Herpesvirus 1 (BHV-1) replication through a dose-dependent increase in cytopathy and increased viral titer. Furthermore, TCDD was able to trigger BHV-1-induced apoptosis by up-regulating the activation of initiator caspases 8 and 9, as well as of effector caspase 3. Since TCDD activates caspase 3 after 4,h of infection, we have hypothesized an involvement of BHV-1 infected cell protein 0 (bICP0) in this process. Such protein, the major transcriptional regulatory protein of BHV-1, has been shown to indirectly induce caspase 3 activation and apoptosis. In order to elucidate the role of bICP0 in this apoptotic pathway, here we have analyzed the effects of TCDD on bICP0 expression. Following infection of bovine cells with BHV-1, we detected apoptotic features already at 12,h after infection, only in TCDD exposed groups. Furthermore, in the presence of different doses of TCDD, we observed a time-dependent modulation and increase of bICP0 gene expression levels, as revealed by RT-PCR analysis. Western blot analysis and immunocytochemistry revealed that TCDD induced an increase of bICP0 protein levels in a dose-dependent manner, compared to unexposed groups. Moreover, Western blot analysis of nuclear and cytosolic fractions of infected cells revealed that TCDD anticipated the presence of bICP0 protein in the cytoplasm. In conclusion, both the increase of replication of BHV-1 and anticipation of BHV-1-induced apoptosis could be the result of a relationship between TCDD and bICP0. J. Cell. Biochem. 111: 333,342, 2010. © 2010 Wiley-Liss, Inc. [source] Cloning, expression, purification and crystallization of a transcriptional regulatory protein (Rv3291c) from Mycobacterium tuberculosis H37RvACTA CRYSTALLOGRAPHICA SECTION D, Issue 10 2004Tripti Shrivastava Rv3291c, the translational product of the Mycobacterium tuberculosisRv3291c gene, is an 18,kDa protein. It is a putative transcriptional regulatory protein belonging to the leucine-responsive regulatory protein/asparagine synthase C (Lrp/AsnC) family, which are proteins that have been identified in archaea and bacteria. Rv3291c probably plays a significant role during the persistent/latent phase of M. tuberculosis, as supported by its up-regulation several-fold during this stage. Orthorhombic crystals of recombinant Rv3291c have been grown from trisodium citrate dihydrate-buffered solutions containing monoammonium dihydrogen phosphate. Diffraction data extending to 2.7,Å have been collected from a single crystal with unit-cell parameters a = 99.6, b = 100.7, c = 100.6,Å. Assuming an octamer in the asymmetric unit results in a Matthews coefficient (VM) of 1.75,Å3,Da,1, corresponding to a solvent content of about 30%. [source] Evaluating low level sequence identitiesFEBS JOURNAL, Issue 2 2001AROM homologous?, Are Aspergillus QUTA A review published several years ago [Hawkins, A.R. & Lamb, H.K. (1995) Eur. J. Biochem. 232, 7,18] proposed that genetic, biochemical and physiological data can override sequence comparison in the determination of homology in instances where structural information is unavailable. Their lead example was the hypothesis that the transcriptional activator protein for quinate catabolism in Aspergillus nidulans, QUTA, is derived from the pentafunctional AROM protein by a gene duplication followed by cleavage [Hawkins, A.R., Lamb, H.K., Moore, J.D. & Roberts, C.F. (1993) Gene136, 49,54]. We tested this hypothesis by a sensitive combination of position-specific log-odds scoring matrix methods. The position-specific log-odds scoring matrices were derived from a large number of 3-dehydroquinate synthase and 5- enolpyruvylshikimate-3-phosphate synthase domains that were proposed to be the domains from the AROM protein that gave rise to the transcriptional activator protein for quinate metabolism. We show that the degree and pattern of similarity between these position-specific log-odds scoring matrices and the transcriptional activator protein for quinate catabolism in A. nidulans is that expected for random sequences of the same composition. This level of similarity provides no support for the suggested gene duplication and cleavage. The lack of any trace of evidence for homology following a comprehensive sequence analysis indicates that the homology hypothesis is without foundation, underlining the necessity to accept only similarity of sequence and/or structure as evidence of evolutionary relatedness. Further, QUTA is homologous throughout its entire length to an extended family of fungal transcriptional regulatory proteins, rendering the hypothesized QUTA,AROM homology even more problematic. [source] A chimeric activator of transcription that uses two DNA-binding domains to make simultaneous contact with pairs of recognition sitesMOLECULAR MICROBIOLOGY, Issue 4 2001Robert C. Langdon Many well-known transcriptional regulatory proteins are composed of at least two independently folding domains and, typically, only one of these is a DNA-binding domain. However, some transcriptional regulators have been described that have more than one DNA-binding domain. Regulators with a single DNA-binding domain often bind co-operatively to the DNA in homotypic or heterotypic combinations, and two or more DNA-binding domains of a single regulatory protein can also bind co-operatively to suitably positioned recognition sequences. Here, we examine the behaviour of a chimeric activator of transcription with two different DNA-binding domains, that of the bacteriophage , cI protein and that of the Escherichia coli cyclic AMP receptor protein. We show that these two DNA-binding moieties, when present in the same molecule, can bind co-operatively to a pair of cognate recognition sites located upstream of a test promoter, thereby permitting the chimera to function as a particularly strong activator of transcription from this promoter. Our results show how such a bivalent DNA-binding protein can be used to regulate transcription differentially from promoters that bear either one or both recognition sites. [source] | |||||||||||||