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Various Signaling Pathways (various + signaling_pathway)
Selected AbstractsCellular response to oxidative stress: Signaling for suicide and survival,JOURNAL OF CELLULAR PHYSIOLOGY, Issue 1 2002Jennifer L. Martindale Reactive oxygen species (ROS), whether produced endogenously as a consequence of normal cell functions or derived from external sources, pose a constant threat to cells living in an aerobic environment as they can result in severe damage to DNA, protein, and lipids. The importance of oxidative damage to the pathogenesis of many diseases as well as to degenerative processes of aging has becoming increasingly apparent over the past few years. Cells contain a number of antioxidant defenses to minimize fluctuations in ROS, but ROS generation often exceeds the cell's antioxidant capacity, resulting in a condition termed oxidative stress. Host survival depends upon the ability of cells and tissues to adapt to or resist the stress, and repair or remove damaged molecules or cells. Numerous stress response mechanisms have evolved for these purposes, and they are rapidly activated in response to oxidative insults. Some of the pathways are preferentially linked to enhanced survival, while others are more frequently associated with cell death. Still others have been implicated in both extremes depending on the particular circumstances. In this review, we discuss the various signaling pathways known to be activated in response to oxidative stress in mammalian cells, the mechanisms leading to their activation, and their roles in influencing cell survival. These pathways constitute important avenues for therapeutic interventions aimed at limiting oxidative damage or attenuating its sequelae. Published 2002 Wiley-Liss, Inc. [source] The cytoplasmic tail of the ,3 integrin subunit promotes neurite outgrowth in PC12 cellsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 6 2005Nadja Mechai Abstract Binding of integrins to proteins of the extracellular matrix (ECM) provides structural and signaling information for biological processes such as cell proliferation, migration, neurite outgrowth, and differentiation. Integrins represent a family of heterodimeric transmembrane cell surface receptors. Besides connecting the ECM with the cytoskeleton, integrins also induce various signaling pathways in response to ligand binding. Integrin ligation leads to cytoplasmic protein,protein interactions requiring both integrin cytoplasmic tails. These sequences are initiation points for focal adhesion formation and subsequent signal transduction cascades. In this study, we addressed the question of whether the short cytoplasmic tail of the ,3 integrin subunit of ,3,1 integrin is required for ,3,1 integrin-dependent processes. For this purpose, cDNA representing the extracellular and transmembrane domain of the interleukin 2 receptor (IL2R) , subunit and the cytoplasmic sequence of the ,3 integrin subunit was transfected into PC12 cells. Autonomous expression of the cytoplasmic ,3 tail does not affect attachment but leads to inhibition of neuronal differentiation on laminin 5. This indicates that the cytoplasmic ,3 sequence is not required for cell attachment but is necessary for long-term adhesion and for the reorganization of the cytoskeleton that precedes neuronal differentiation. Inhibition of neurite outgrowth by chimeric IL2R-,3 can be rescued by treatment of transfected cells with the pharmacological inhibitor Y27632, which inhibits the RhoA downstream effector Rho kinase ,. © 2005 Wiley-Liss, Inc. [source] Developmental profile of ErbB receptors in murine central nervous system: Implications for functional interactionsJOURNAL OF NEUROSCIENCE RESEARCH, Issue 5 2005Irina J. Fox Abstract The ErbB family, ErbB1 (also known as the epidermal growth factor receptor EGFR), ErbB2, ErbB3, and ErbB4 comprise a group of receptor tyrosine kinases that interact with ligands from the epidermal growth factor (EGF) superfamily, subsequently dimerize, catalytically activate each other by cross-phosphorylation, and then stimulate various signaling pathways. To gain a better understanding of in vivo functions of ErbB receptors in the central nervous system, the current study examined their mRNA expression throughout development in the mouse brain via in situ hybridization. EGFR, ErbB2, and ErbB4 exhibited distinct but sometimes overlapping distributions in multiple cell types within germinal zones, cortex, striatum, and hippocampus in prenatal and postnatal development. In addition, a subpopulation of cells positive for ErbB4 mRNA in postnatal cortex and striatum coexpressed mRNA for either EGFR or GAD67, a marker for ,-aminobutyric acid (GABA)ergic interneurons, suggesting that both ErbB4 and EGFR are coexpressed in GABAergic interneurons. In contrast, ErbB3 mRNA was not detected within the brain during development and only appeared in white matter tracts in adulthood. Together, these findings suggest that ErbB receptors might mediate multiple functions in central nervous system development, some of which may be initiated by EGFR/ErbB4 heterodimers in vivo. © 2005 Wiley-Liss, Inc. [source] BTB and TAZ domain scaffold proteins perform a crucial function in Arabidopsis developmentTHE PLANT JOURNAL, Issue 1 2009Hélène S. Robert Summary In Arabidopsis, bric-a-brac, tramtrack and broad (BTB) domain scaffold proteins form a family of 80 proteins that have involvement in various signaling pathways. The five members of the subfamily of BTB AND TAZ DOMAIN proteins (BT1,BT5) have a typical domain structure that is only observed in land plants. Here, we present a functional analysis of the BT family, of which at least four members are encoded by auxin-responsive genes. BT1 is a short-lived protein that is characteristically targeted for degradation by the 26S proteasome. Expression pattern, gene structure and sequence analyses indicate that BT1 and BT2 are closely related. They both localize to the nucleus and the cytosol, whereas the remaining BT proteins were determined as cytosolic proteins. Detailed molecular and phenotypic analysis of plants segregating for null mutations in the BT family revealed substantial redundancy among the BT members, and highlighted that BT proteins perform crucial roles in both male and female gametophyte development. BT2 seems to be the predominant gene in this process, in which it is functionally replaced by BT3 and BT1 through reciprocal transcription regulation. Compensational expression alters the steady-state mRNA levels among the remaining BT family members when other BT members are lost, and this contributes towards functional redundancy. Our data provide a surprising example of functional redundancy among genes required during gametophyte development, something that could not be detected in the current screens for gametophyte mutants. [source] | ||||||||||