Determination of specific GTPase (EC 3.6.1.—) activity in turkey erythrocyte membranes was achieved using low concentration of GTP (0.25 μM), ... 70% increase in GTP hydrolysis. The stimulation of GTPase activity by catecholamines required the presence of Mg2+ ... specific activities (pmol 32Pi/mg protein min): basal GTPase (determined in the absence of catecholamine), 6–11; catecholamine-stimulated GTPase, 3–7; and residual non-specific NTPase, 3–5. The stimulation of GTPase activity by catecholamines fulfilled the stereospecific requirements of ...
Tópico(s): Ion channel regulation and function
1976 - Elsevier BV | Biochimica et Biophysica Acta (BBA) - Proteins and Proteomics
Gernot Sander, Robert C. Marsh, Andrea Parmeggiani,
... 30-S CsCl core was unable to sustain GTPase activity dependent on elongation factor G (EF-G), ... the Mg2+ optimum of the EF-T-dependent GTPase reaction from approximately 20 mM to approximately 10 ... the absence of methanol the EF-G-dependent (GTPase reaction at low concentration of monovalent cations depends ... S subunit alone (30-S-uncoupled EF-G GTPase). Addition of the intact 30-S subunit but ... inhibition of the 30-S-uncoupled EF-G-GTPase by NH4+. The 30-S CsCl core caused ... methanol was present. 30-S-uncoupled EF-G GTPase activity was lower than the GTPase activity dependent ...
Tópico(s): DNA and Nucleic Acid Chemistry
1976 - Wiley | European Journal of Biochemistry
Klaus Aktories, G. Schultz, K H Jakobs,
The activity of enzymes exhibiting GTPase activity was determined in membrane preparations of hamster adipocytes. Two GTPases with apparent Km values of about 0.2 microM GTP (low Km GTPase) and 180 microM GTP (high Km GTPase) were found. The effects of various agents that ... cyclase were investigated with these two forms of GTPase. None of the stimulatory or inhibitory agonists studied affected the activity of the high Km GTPase(s). However, factors inhibiting adenylate cyclase, such as ... methylpyrazole, and N6-phenylisopropyladenosine, stimulated the low Km GTPase by 50--100% without an apparent lag phase. ...
Tópico(s): Protein Kinase Regulation and
1982 - American Society for Pharmacology and Experimental Therapeutics | Molecular Pharmacology
Y. Hata, Akira Kikuchi, Takuya Sasaki, Michael D. Schaber, W. Wayt Gibbs, Yoshimi Takai,
ras p21 GTPase-activating protein (GAP) has been proposed to interact with the putative effector domain of ras p21s, and smg ... the effects of ras p21 GAP on the GTPase activity of smg p21 purified from human platelets, ... smg p21 on the ras p21 GAP-stimulated GTPase activity of c-Ha-ras p21 purified from ... on the smg p21 GAP1- or -2-stimulated GTPase activity of smg p21. ras p21 GAP stimulated the GTPase activity of c-Ha-ras p21 but not ... p21, however, inhibited the ras p21 GAP-stimulated GTPase activity of c-Ha-ras p21 in a ...
Tópico(s): Growth Hormone and Insulin-like Growth Factors
1990 - Elsevier BV | Journal of Biological Chemistry
Directory of Open Access Books (DOAB)
Rudravajhala Ravindra, Robert S. Aronstam,
... of anti-tubulin antibodies on the low Km GTPase activity associated with transducer G proteins was examined ... striatum by conventional procedures, and the low Km GTPase activity (EC 3.6.1.-) was determined using [ ... 0.2 to 2.0 μM unlabeled GTP. GTPase activity was linear for up to 30 min ... β-tubulin antibodies (10 μg) stimulated G protein GTPase activity. Anti-β-tubulin antibody (10 μg) stimulated GTPase activity by about 60% at each time point, ... α-tubulin or polyclonal anti-tubulin antibodies stimulated GTPase activity by only 20–30% at each time ...
Tópico(s): Receptor Mechanisms and Signaling
1990 - Elsevier BV | Biochemical Pharmacology
Luc Vachon, Tommaso Costa, A. Herz,
... and loss of responsiveness of the opioid-controlled GTPase and adenylate cyclase were compared in membranes derived ... DADLE, a rapid desensitization of the opioid-stimulated GTPase occurred with a time course distinguishable as two ... whose half-lives were similar to those for GTPase desensitization (7 and 120 min). However, when [3H] ... 57 min. Whereas the loss of responsiveness of GTPase to DADLE was entirely accounted for by a ... hr of pretreatment with DADLE, the opioid-stimulated GTPase was desensitized by 65%, whereas 80% of maximal ...
Tópico(s): Pharmacological Receptor Mechanisms and Effects
1987 - American Society for Pharmacology and Experimental Therapeutics | Molecular Pharmacology
Mary J. Clark, Fedor Medzihradsky,
... and delta types stimulated low-Km guanosine triphosphatase (GTPase) in membranes, from the brain of the rat ... to opioid receptor. In general, kappa ligands stimulated GTPase to a lesser degree than mu or delta ... of a given type of opioid receptor to GTPase was resolved by direct or protective alkylation of ... membranes with β-funaltrexamine abolished the stimulation of GTPase by sufentanil and levorphanol (mu), but not by ... Superfit gradually reduced the extent of stimulation of GTPase by DSLET. The successive treatment of membranes with ...
Tópico(s): Receptor Mechanisms and Signaling
1987 - Elsevier BV | Neuropharmacology
Debra J. Gawler, Miles D. Houslay,
Insulin stimulated the activity of a high‐affinity GTPase activity in human platelet membranes some 62% over ... K m for GTP of the insulin‐stimulated GTPase was 0.6 μM GTP. Treatment of isolated ... pertussis toxin, blocked insulin's ability to stimulate GTPase activity. Cholera toxin acted as a more potent inhibitor of the insulin‐stimulated GTPase activity than that of the GTPase activity of the stimulatory guanine nucleotide regulatory protein, ... 1 ). Mixed ligand experiments showed that insulin stimulated GTPase activity in an additive fashion to GTPase activity ...
Tópico(s): Lipid Membrane Structure and Behavior
1987 - Wiley | FEBS Letters
Mary W. Wilde, Kenneth E. Carlson, David R. Manning, S H Zigmond,
... The chemoattractant stimulation of a pertussis toxin-sensitive GTPase activity on PMN membranes was used as an ... of signal transduction. We find a decreased basal GTPase activity and a decrease in the ability of ... incubated with the chemotactic peptide FNLLP. The basal GTPase activity is decreased by up to 70% and the peptide-stimulated GTPase activity by up to 95% on membranes from ... 7) M FNLLP. The decrease in peptide-stimulated GTPase activity cannot be accounted for by the decreased ... receptors that remain available for binding stimulate the GTPase activity with a decreased efficiency. The ligand-induced ...
Tópico(s): Cell Adhesion Molecules Research
1989 - Elsevier BV | Journal of Biological Chemistry
... rasH has been compared with their effects on GTPase and guanine nucleotide exchange rates of p21. The ... exchange in the absence of an effect on GTPase. In contrast, the more modest enhancement of exchange ... result in both a 5-fold reduction in GTPase and a 10-fold increase in nucleotide exchange. ... mutant Ile-59 displayed a comparable decrease in GTPase without an effect on nucleotide exchange. The activating ... may thus represent a combined effect of reduced GTPase and increased exchange. Similarly, the strongly activating mutation ...
Tópico(s): Biochemical and Molecular Research
1988 - Taylor & Francis | Molecular and Cellular Biology
Hiroshi Homma, Donald J. Hanahan,
The GTPase activities of rabbit platelet membrane were stimulated by platelet activating factor (PAF) in a receptor-mediated manner. The activities of the GTPase were investigated in the platelets which had been ... were required for stimulation of the receptor-coupled GTPase. In addition the extent of stimulation of the GTPase by PAF was also decreased. By contrast thrombin stimulation of GTPase activity was unaffected by this process. In platelets ... 2 mm), PAF could stimulate the receptor-coupled GTPase only to a much lower extent in these ...
Tópico(s): Blood Coagulation and Thrombosis Mechanisms
1988 - Elsevier BV | Archives of Biochemistry and Biophysics
Larry A. Feig, Geoffrey M. Cooper,
... rasH has been compared with their effects on GTPase and guanine nucleotide exchange rates of p21. The ... exchange in the absence of an effect on GTPase. In contrast, the more modest enhancement of exchange ... result in both a 5-fold reduction in GTPase and a 10-fold increase in nucleotide exchange. ... mutant Ile-59 displayed a comparable decrease in GTPase without an effect on nucleotide exchange. The activating ... may thus represent a combined effect of reduced GTPase and increased exchange. Similarly, the strongly activating mutation ...
Tópico(s): Ion channel regulation and function
1988 - Taylor & Francis | Molecular and Cellular Biology
Wayne Hoss, Paul Franklin, Shahnaz Ghodsi-Hovsepian,
... with the attendant hydrolysis of GTP. The resulting GTPase activity was characterized in rat brain with a ... washed membranes suggested the presence of two distinct GTPases, a low Km GTPase with an apparent Km value of 0.35 ± ... Km component. Low Km (but not high Km) GTPase activity is stimulated by muscarinic and opioid agonists ... preparation. Both carbamylcholine-stimulated and basal low Km GTPase activities, but not the high Km component, are ... of ATP, demonstrating the specificity of low Km GTPase for guanine nucleotides. Opioid- and muscarinic-stimulated GTPase ...
Tópico(s): Receptor Mechanisms and Signaling
1988 - Elsevier BV | Journal of Pharmaceutical Sciences
Kathy W.K. Tse, May Dang-Lawson, Rosaline L. Lee, Doris Vong, Anica Bulic, Leonard Buckbinder, Michael R. Gold,
... of Pyk2 and FAK. Activation of the Rap GTPases is critical for BCR-induced integrin activation as ... and FAK are downstream targets of the Rap GTPases that play a key role in regulating B ... of Pyk2 and FAK. Activation of the Rap GTPases is critical for BCR-induced integrin activation as ... and FAK are downstream targets of the Rap GTPases that play a key role in regulating B ... immune synapse formation requires activation of the Rap GTPases (6Lin K.B. Freeman S.A. Zabetian S. ... We also showed that activation of the Rap GTPases was critical for BCR/integrin signaling to induce ...
Tópico(s): Immunotherapy and Immune Responses
2009 - Elsevier BV | Journal of Biological Chemistry
Geerten P. van Nieuw Amerongen, Victor W.M. van Hinsbergh,
... of members of the Rho family of small GTPases, with its main members RhoA, Rac1, and Cdc42, ... Bryan and d'Amore (3) for review]. Rho GTPases modulate a diversity of cellular processes, including extracellular ... the GTP-binding-GTP-hydrolysis cycle of Rho GTPases is highly coordinated in a spatiotemporally controlled manner ... During angiogenesis, specific guanine exchange factors (RhoGEFs) and GTPase-activating proteins (RhoGAPs) are dedicated to regulate RhoA ... Amore PA. What tangled webs they weave: Rho-GTPase control of angiogenesis. Cell Mol Life Sci 64: ...
Tópico(s): Intracerebral and Subarachnoid Hemorrhage Research
2009 - American Physical Society | AJP Heart and Circulatory Physiology
Yunjuan Zhu, Yuanjun Wu, Jae Il Kim, Zhimin Wang, Yehia Daaka, Zhongzhen Nie,
... of focal adhesion remodeling. AGAP2 is an Arf GTPase-activating protein that regulates endosomal trafficking and is ... of the focal adhesions is independent of its GTPase-activating protein activity but may involve its N- ... of focal adhesion remodeling. AGAP2 is an Arf GTPase-activating protein that regulates endosomal trafficking and is ... of the focal adhesions is independent of its GTPase-activating protein activity but may involve its N- ... growth factor; Erk, extracellular signal-regulated kinase; GAP, GTPase-activating protein; GLD, G protein-like domain; ASAP, ...
Tópico(s): Cellular transport and secretion
2009 - Elsevier BV | Journal of Biological Chemistry
Hye-Young Suh, Dong‐Won Lee, Kwang-Hoon Lee, Bonsu Ku, Sung-Jin Choi, Jae‐Sung Woo, Yeon‐Gil Kim, Byung‐Ha Oh,
... SidM/DrrA reconfigures the Switch regions of the GTPase domain of Rab1, as eukaryotic GEFs do toward ... sub-group of the Ras superfamily of small GTPases and regulate all aspects of secretory vesicle trafficking. ... a slow process by itself, because their intrinsic GTPase activity is low, and GDP release from the ... Wittinghofer, 2001). The catalytic activity is enhanced by GTPase-activating proteins, whereas GDP release and the following ... to as SidMcd, in complex with the core GTPase domain of the Rab1 variant, referred to as ...
Tópico(s): Tardigrade Biology and Ecology
2009 - Springer Nature | The EMBO Journal
Zhenglong Wang, Yosuke Kumamoto, Ping Wang, Xiaoqing Gan, David M. Lehmann, Alan V. Smrcka, Lauren Cohn, Akiko Iwasaki, Lin Li, Dianqing Wu,
... have established that the Rho family of small GTPases regulates leukocyte migration (1Ridley A.J. J. Cell ... RhoA are the three best studied Rho small GTPases. In myeloid cells, Cdc42 regulates directionality by directing ... key regulators for the activity of these small GTPases. GEFs activate small GTPases by promoting the loading of GTP to the small GTPases, a rate-limiting step in GTPase regulation (8Ridley A.J. Trends Cell Biol. 2001; ... pulldown assays for determining the activity of small GTPases were carried essentially as previously described. In brief, ...
Tópico(s): Cytokine Signaling Pathways and Interactions
2009 - Elsevier BV | Journal of Biological Chemistry
Yao‐Wen Wu, Roger S. Goody, Ruben Abagyan, Kirill Alexandrov,
... of more than 60 members of the Rab GTPase family: central regulators of intracellular vesicular transport (10Schwartz ... 294) Google Scholar). The C terminus of Rab GTPases is naturally disordered, a feature that is important ... binding and selection. REP recruits newly synthesized Rab GTPases and then presents them to the RabGGTase. The ... are transferred onto the C terminus of Rab GTPase (11Goody R.S. Rak A. Alexandrov K. Cell ... complex by forming binding interfaces with both Rab GTPase and RabGGTase (17Rak A. Pylypenko O. Niculae A. ...
Tópico(s): Peptidase Inhibition and Analysis
2009 - Elsevier BV | Journal of Biological Chemistry
Xiao Zhang, Freya Shephard, Hong B. Kim, I. Palmer, Selina McHarg, Gregory J.S. Fowler, Luke O'neill, Endre Kiss‐Toth, Eva E. Qwarnström,
... components in coordination with activation of the Ras GTPase. Using mutagenesis, we demonstrate that TILRR function is ... components in coordination with activation of the Ras GTPase. Using mutagenesis, we demonstrate that TILRR function is ... and the cytoskeleton and controlled by the small GTPases (7.Qwarnström E.E. MacFarlane S.A. Page ... with mechanotransduction by controlling induction of the Ras GTPase.DISCUSSIONWe report on a novel IL-1RI co- ... the MyD88 adapter, control induction of the Ras GTPase, and amplify activation of NF-κB and inflammatory ...
Tópico(s): interferon and immune responses
2009 - Elsevier BV | Journal of Biological Chemistry
Shu‐ou Shan, Sandra L. Schmid, Xin Zhang,
The GTP-binding proteins or GTPases comprise a superfamily of proteins that provide molecular switches in numerous cellular processes. The "GTPase switch" paradigm, in which a GTPase acts as a bimodal switch that is turned " ... used to interpret the regulatory mechanism of many GTPases for more than two decades. Nevertheless, recent work has unveiled an emerging class of "multistate" regulatory GTPases that do not adhere to this classical paradigm. ... of relying on external nucleotide exchange factors or GTPase activating proteins to switch between the on and ...
Tópico(s): CRISPR and Genetic Engineering
2009 - American Chemical Society | Biochemistry
... triggering requires the coordinated activation of Rho family GTPases that cycle between active and inactive conformations. This is controlled by GTPase-activating proteins (GAP), which regulate inactivation of Rho GTPases, and guanine exchange factors, which mediate their activation. ... has centered on guanine exchange factors for Rho GTPases in T cell activation, the identity and functional ... triggering requires the coordinated activation of Rho family GTPases that cycle between active and inactive conformations. This ...
Tópico(s): Protein Kinase Regulation and
2009 - Elsevier BV | Journal of Biological Chemistry
Kanami Uesugi, Izumi Oinuma, Hironori Katoh, Masahiko Negishi,
... Rnd1, a member of Rnd subfamily of Rho GTPases. However, signaling pathways of Plexin-D1 and Plexin- ... and these actions required Rnd2, another Rnd subfamily GTPase. Rnd2 bound to Plexin-D1 in cortical neurons, ... Rnd1, a member of Rnd subfamily of Rho GTPases. However, signaling pathways of Plexin-D1 and Plexin- ... and these actions required Rnd2, another Rnd subfamily GTPase. Rnd2 bound to Plexin-D1 in cortical neurons, ... n; FBS, fetal bovine serum; FN, fibronectin; GAP, GTPase-activating protein; GFP, green fluorescent protein; GST, glutathione ...
Tópico(s): Zebrafish Biomedical Research Applications
2009 - Elsevier BV | Journal of Biological Chemistry
Jan-Christian Schuette, F.V. Murphy, Ann C. Kelley, John R. Weir, Jan Giesebrecht, Sean R. Connell, Justus Loerke, Thorsten Mielke, Wei Zhang, Pawel A. Penczek, V. Ramakrishnan, Christian M. T. Spahn,
Article19 February 2009free access GTPase activation of elongation factor EF-Tu by the ribosome during decoding Jan-Christian Schuette Jan-Christian Schuette Institut für Medizinische ... decoding centre of the 30S subunit to the GTPase centre of EF-Tu. Introduction Ribosomes are large ... and Spahn, 2006). Many of these factors are GTPases, among them initiation factor IF2, elongation factors EF- ... each of the stages of translation. Among the GTPase translation factors, EF-Tu has an essential function ... near-cognate) tRNA leads to an acceleration of GTPase activation and GTP hydrolysis. This suggests that binding ...
Tópico(s): Plant Virus Research Studies
2009 - Springer Nature | The EMBO Journal