The Experts below are selected from a list of 1761 Experts worldwide ranked by ideXlab platform
Jonathan A Jeyaratnam - One of the best experts on this subject based on the ideXlab platform.
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the guanylate binding proteins emerging insights into the biochemical properties and functions of this family of large interferon induced Guanosine Triphosphatase
Journal of Interferon and Cytokine Research, 2011Co-Authors: Deborah J Vestal, Jonathan A JeyaratnamAbstract:Originally identified by their unusual ability to bind Guanosine monophosphate (GMP) nucleotide agarose, the guanylate-binding proteins (GBPs) were used extensively to promote our understanding of interferon-induced gene transcription and as markers of interferon responsiveness. Structural and biochemical analyses of human GBP-1 subsequently demonstrated that the GBPs are a unique subfamily of Guanosine Triphosphatase (GTPases) that hydrolyze Guanosine triphosphate (GTP) to both Guanosine diphosphate (GDP) and GMP. As members of the larger dynamin superfamily of GTPases, GBPs exhibit such properties as nucleotide-dependent oligomerization and concentration-dependent GTPase activity. Recently, progress has been made in assigning functions to members of the GBP family. While many of these functions involve protection against intracellular pathogens, a growing number of them are not directly related to pathogen protection. It is currently unclear how the unusual properties of GBPs contribute to this growing ...
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the guanylate binding proteins emerging insights into the biochemical properties and functions of this family of large interferon induced Guanosine Triphosphatase
Journal of Interferon and Cytokine Research, 2011Co-Authors: Deborah J Vestal, Jonathan A JeyaratnamAbstract:Originally identified by their unusual ability to bind Guanosine monophosphate (GMP) nucleotide agarose, the guanylate-binding proteins (GBPs) were used extensively to promote our understanding of interferon-induced gene transcription and as markers of interferon responsiveness. Structural and biochemical analyses of human GBP-1 subsequently demonstrated that the GBPs are a unique subfamily of Guanosine Triphosphatase (GTPases) that hydrolyze Guanosine triphosphate (GTP) to both Guanosine diphosphate (GDP) and GMP. As members of the larger dynamin superfamily of GTPases, GBPs exhibit such properties as nucleotide-dependent oligomerization and concentration-dependent GTPase activity. Recently, progress has been made in assigning functions to members of the GBP family. While many of these functions involve protection against intracellular pathogens, a growing number of them are not directly related to pathogen protection. It is currently unclear how the unusual properties of GBPs contribute to this growing list of functions. As future studies uncover the molecular mechanism(s) of action of the GBPs, we will gain a greater understanding of how individual GBPs can mediate what currently appears to be a divergent set of functions.
Deborah J Vestal - One of the best experts on this subject based on the ideXlab platform.
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the guanylate binding proteins emerging insights into the biochemical properties and functions of this family of large interferon induced Guanosine Triphosphatase
Journal of Interferon and Cytokine Research, 2011Co-Authors: Deborah J Vestal, Jonathan A JeyaratnamAbstract:Originally identified by their unusual ability to bind Guanosine monophosphate (GMP) nucleotide agarose, the guanylate-binding proteins (GBPs) were used extensively to promote our understanding of interferon-induced gene transcription and as markers of interferon responsiveness. Structural and biochemical analyses of human GBP-1 subsequently demonstrated that the GBPs are a unique subfamily of Guanosine Triphosphatase (GTPases) that hydrolyze Guanosine triphosphate (GTP) to both Guanosine diphosphate (GDP) and GMP. As members of the larger dynamin superfamily of GTPases, GBPs exhibit such properties as nucleotide-dependent oligomerization and concentration-dependent GTPase activity. Recently, progress has been made in assigning functions to members of the GBP family. While many of these functions involve protection against intracellular pathogens, a growing number of them are not directly related to pathogen protection. It is currently unclear how the unusual properties of GBPs contribute to this growing ...
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the guanylate binding proteins emerging insights into the biochemical properties and functions of this family of large interferon induced Guanosine Triphosphatase
Journal of Interferon and Cytokine Research, 2011Co-Authors: Deborah J Vestal, Jonathan A JeyaratnamAbstract:Originally identified by their unusual ability to bind Guanosine monophosphate (GMP) nucleotide agarose, the guanylate-binding proteins (GBPs) were used extensively to promote our understanding of interferon-induced gene transcription and as markers of interferon responsiveness. Structural and biochemical analyses of human GBP-1 subsequently demonstrated that the GBPs are a unique subfamily of Guanosine Triphosphatase (GTPases) that hydrolyze Guanosine triphosphate (GTP) to both Guanosine diphosphate (GDP) and GMP. As members of the larger dynamin superfamily of GTPases, GBPs exhibit such properties as nucleotide-dependent oligomerization and concentration-dependent GTPase activity. Recently, progress has been made in assigning functions to members of the GBP family. While many of these functions involve protection against intracellular pathogens, a growing number of them are not directly related to pathogen protection. It is currently unclear how the unusual properties of GBPs contribute to this growing list of functions. As future studies uncover the molecular mechanism(s) of action of the GBPs, we will gain a greater understanding of how individual GBPs can mediate what currently appears to be a divergent set of functions.
Gloria H Biddlecome - One of the best experts on this subject based on the ideXlab platform.
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Guanosine Triphosphatase activating proteins for heterotrimeric g proteins
Advances in pharmacology, 1997Co-Authors: Elliott M Ross, Jun Wang, Gloria H BiddlecomeAbstract:Publisher Summary G-proteins convey information by traversing a cycle of controlled Guanosine Triphosphatase (GTP) binding and hydrolysis. Receptors initiate a signal by promoting the binding of GTP to the G-protein a subunit, thereby activating the G-protein and causing it to activate its effector. Activation is terminated when bound GTP is hydrolyzed. Hydrolysis of G α -bound GTP is an unusually and anomalously slow enzymatic reaction. Although the rate of deactivation of adenylyl cyclase is generally about equal to the rate of hydrolysis of G s -bound GTP, physiological rates of termination of most G-protein signals in cells are much faster than the measured rate of hydrolysis of GTP by the relevant isolated G-protein. In such cases, hydrolysis of bound GTP is accelerated by GTPase-activating proteins (GAPs). G-protein GAPs perform one or more important regulatory functions. The first GAPs for heterotrimeric G-proteins to be identified were the G-protein-regulated effectors phospholipase C- β (PLC- β ) and the cyclic GMP phosphodiesterase of photoreceptor cells. The GAP activity of effectors is thought to enhance the temporal resolution of signaling, as discussed earlier, or to increase the selectivity of the G-protein among different receptors. The recently recognized RGS proteins, whose prototypes are involved in desensitization or antagonism of G-protein signaling, are also G-protein GAPs. Their primary function is assumed to be attenuation of signaling, although the regulation of RGS proteins is only being recently investigated. GAPs for small monomeric GTP-binding proteins such as p21 ras also are negative signaling elements. Lastly, GAPs for some of the monomeric GTP-binding proteins involved in organelle trafficking are thought to terminate G-protein-mediated assembly, fusion, or transit functions, although this role has not been conclusively demonstrated. This chapter describes the activities of two GAPS for heterotrimeric G-proteins, one G-protein is an effector and the other a newly identified GAP whose physiological role is still unknown.
Filippo Rossi - One of the best experts on this subject based on the ideXlab platform.
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tyrosine phosphorylation and subcellular redistribution of p125 ras Guanosine Triphosphatase activating protein in human neutrophils stimulated with fmlp
FEBS Letters, 1996Co-Authors: Stefano Dusi, Marta Donini, Frans B. Wientjes, Filippo RossiAbstract:In this paper, we show that the p125 ras Guanosine Triphosphatase-activating protein (p125 GAP) is present in the cytosol of human neutrophils and is transiently tyrosine phosphorylated and translocated to the membranes upon cell activation with formyl-methionyl-leucyl-phenylalanine (FMLP). When concanavalin A (ConA) or phorbol 12-myristate 13-acetate (PMA), which both induced a long-lasting respiratory burst, were used as stimuli, tyrosine phosphorylation and translocation of p125 GAP did not occur.
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Translocation of p190rho Guanosine Triphosphatase-Activating Protein from Cytosol to the Membrane in Human Neutrophils Stimulated with Different Agonists
Biochemical and biophysical research communications, 1996Co-Authors: Stefano Dusi, Marta Donini, Frans B. Wientjes, Filippo RossiAbstract:In this paper, we investigated the subcellular distribution of p190rho Guanosine Triphosphatase-activating protein (p190 GAP) in human neutrophils stimulated with different agonists. The results show that in neutrophils treated with formyl-methionyl-leucyl-phenylalanine (FMLP) (1) p190 GAP was translocated from the cytosol to the membranes; (2) the translocation of p190 GAP took place only at doses of FMLP that induced the translocation of rac 1 and rac 2 and the activation of the NADPH oxidase; and (3) the kinetic of translocation of p190 GAP paralleled that of rac 1 and rac 2. However, when the agonist was concanavalin A (ConA) or phorbol 12-myristate 13-acetate (PMA), rac 1 and rac 2, but not the p190 GAP, were translocated.
Gregg G Gundersen - One of the best experts on this subject based on the ideXlab platform.
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rho Guanosine Triphosphatase mediates the selective stabilization of microtubules induced by lysophosphatidic acid
Journal of Cell Biology, 1998Co-Authors: Tiffani A Cook, Takayuki Nagasaki, Gregg G GundersenAbstract:The asymmetric distribution of stable, posttranslationally modified microtubules (MTs) contributes to the polarization of many cell types, yet the factors controlling the formation of these MTs are not known. We have found that lysophosphatidic acid (LPA) is a major serum factor responsible for rapidly generating stable, detyrosinated (Glu) MTs in serum-starved 3T3 cells. Using C3 toxin and val14 rho we showed that rho was both necessary and sufficient for the induction of Glu MTs by LPA and serum. Unlike previously described factors that induce MT stability, rho induced the stabilization of only a subset of the MTs and, in wound-edge cells, these stable MTs were appropriately oriented toward the leading edge of the cell. LPA had little effect on individual parameters of MT dynamics, but did induce long states of pause in a subset of MTs near the edge of the cell. Rho stimulation of MT stability was independent of actin stress fiber formation. These results identify rho as a novel regulator of the MT cytoskeleton that selectively stabilizes MTs during cell polarization by acting as a switch between dynamic and stable states of MTs rather than as a modulator of MT assembly and disassembly.