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Dinet C, Mignot T. Unorthodox regulation of the MglA Ras-like GTPase controlling polarity in Myxococcus xanthus. FEBS Lett 2023; 597:850-864. [PMID: 36520515 DOI: 10.1002/1873-3468.14565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 12/23/2022]
Abstract
Motile cells have developed a large array of molecular machineries to actively change their direction of movement in response to spatial cues from their environment. In this process, small GTPases act as molecular switches and work in tandem with regulators and sensors of their guanine nucleotide status (GAP, GEF, GDI and effectors) to dynamically polarize the cell and regulate its motility. In this review, we focus on Myxococcus xanthus as a model organism to elucidate the function of an atypical small Ras GTPase system in the control of directed cell motility. M. xanthus cells direct their motility by reversing their direction of movement through a mechanism involving the redirection of the motility apparatus to the opposite cell pole. The reversal frequency of moving M. xanthus cells is controlled by modular and interconnected protein networks linking the chemosensory-like frizzy (Frz) pathway - that transmits environmental signals - to the downstream Ras-like Mgl polarity control system - that comprises the Ras-like MglA GTPase protein and its regulators. Here, we discuss how variations in the GTPase interactome landscape underlie single-cell decisions and consequently, multicellular patterns.
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Affiliation(s)
- Céline Dinet
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie de la Méditerranée, CNRS-Aix-Marseille University, France
| | - Tâm Mignot
- Laboratoire de Chimie Bactérienne, Institut de Microbiologie de la Méditerranée, CNRS-Aix-Marseille University, France
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2
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Chau JE, Vish KJ, Boggon TJ, Stiegler AL. SH3 domain regulation of RhoGAP activity: Crosstalk between p120RasGAP and DLC1 RhoGAP. Nat Commun 2022; 13:4788. [PMID: 35970859 PMCID: PMC9378701 DOI: 10.1038/s41467-022-32541-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 08/04/2022] [Indexed: 11/10/2022] Open
Abstract
RhoGAP proteins are key regulators of Rho family GTPases and influence a variety of cellular processes, including cell migration, adhesion, and cytokinesis. These GTPase activating proteins (GAPs) downregulate Rho signaling by binding and enhancing the intrinsic GTPase activity of Rho proteins. Deleted in liver cancer 1 (DLC1) is a tumor suppressor and ubiquitously expressed RhoGAP protein; its activity is regulated in part by binding p120RasGAP, a GAP protein for the Ras GTPases. In this study, we report the co-crystal structure of the p120RasGAP SH3 domain bound directly to DLC1 RhoGAP, at a site partially overlapping the RhoA binding site and impinging on the catalytic arginine finger. We demonstrate biochemically that mutation of this interface relieves inhibition of RhoGAP activity by the SH3 domain. These results reveal the mechanism for inhibition of DLC1 RhoGAP activity by p120RasGAP and demonstrate the molecular basis for direct SH3 domain modulation of GAP activity.
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Affiliation(s)
- Jocelyn E Chau
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Kimberly J Vish
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Department of Pharmacology, Yale University, New Haven, CT, USA
| | - Titus J Boggon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
- Department of Pharmacology, Yale University, New Haven, CT, USA
| | - Amy L Stiegler
- Department of Pharmacology, Yale University, New Haven, CT, USA.
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3
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Jaber Chehayeb R, Wang J, Stiegler AL, Boggon TJ. The GTPase-activating protein p120RasGAP has an evolutionarily conserved "FLVR-unique" SH2 domain. J Biol Chem 2020; 295:10511-10521. [PMID: 32540970 PMCID: PMC7397115 DOI: 10.1074/jbc.ra120.013976] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Revised: 06/09/2020] [Indexed: 01/07/2023] Open
Abstract
The Src homology 2 (SH2) domain has a highly conserved architecture that recognizes linear phosphotyrosine motifs and is present in a wide range of signaling pathways across different evolutionary taxa. A hallmark of SH2 domains is the arginine residue in the conserved FLVR motif that forms a direct salt bridge with bound phosphotyrosine. Here, we solve the X-ray crystal structures of the C-terminal SH2 domain of p120RasGAP (RASA1) in its apo and peptide-bound form. We find that the arginine residue in the FLVR motif does not directly contact pTyr1087 of a bound phosphopeptide derived from p190RhoGAP; rather, it makes an intramolecular salt bridge to an aspartic acid. Unexpectedly, coordination of phosphotyrosine is achieved by a modified binding pocket that appears early in evolution. Using isothermal titration calorimetry, we find that substitution of the FLVR arginine R377A does not cause a significant loss of phosphopeptide binding, but rather a tandem substitution of R398A (SH2 position βD4) and K400A (SH2 position βD6) is required to disrupt the binding. These results indicate a hitherto unrecognized diversity in SH2 domain interactions with phosphotyrosine and classify the C-terminal SH2 domain of p120RasGAP as "FLVR-unique."
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Affiliation(s)
- Rachel Jaber Chehayeb
- Yale College, New Haven, Connecticut, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Jessica Wang
- Yale College, New Haven, Connecticut, USA
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
| | - Amy L Stiegler
- Department of Pharmacology, Yale University, New Haven, Connecticut, USA
| | - Titus J Boggon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, USA
- Department of Pharmacology, Yale University, New Haven, Connecticut, USA
- Yale Cancer Center, Yale University, New Haven, Connecticut, USA
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4
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Jaber Chehayeb R, Boggon TJ. SH2 Domain Binding: Diverse FLVRs of Partnership. Front Endocrinol (Lausanne) 2020; 11:575220. [PMID: 33042028 PMCID: PMC7530234 DOI: 10.3389/fendo.2020.575220] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 08/12/2020] [Indexed: 11/27/2022] Open
Abstract
The Src homology 2 (SH2) domain has a special role as one of the cornerstone examples of a "modular" domain. The interactions of this domain are very well-conserved, and have long been described as a bidentate, or "two-pronged plug" interaction between the domain and a phosphotyrosine (pTyr) peptide. Recent work has, however, highlighted unusual features of the SH2 domain that illustrate a greater diversity than was previously appreciated. In this review we discuss some of the novel and unusual characteristics across the SH2 family, including unusual peptide binding pockets, multiple pTyr recognition sites, recognition sites for unphosphorylated peptides, and recently identified variability in the conserved FLVR motif.
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Affiliation(s)
- Rachel Jaber Chehayeb
- Yale College, New Haven, CT, United States
- Department of Molecular Biophysics and Biochemistry, New Haven, CT, United States
| | - Titus J. Boggon
- Department of Molecular Biophysics and Biochemistry, New Haven, CT, United States
- Department of Pharmacology, New Haven, CT, United States
- Yale Cancer Center, Yale University, New Haven, CT, United States
- *Correspondence: Titus J. Boggon
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5
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Jaber Chehayeb R, Stiegler AL, Boggon TJ. Crystal structures of p120RasGAP N-terminal SH2 domain in its apo form and in complex with a p190RhoGAP phosphotyrosine peptide. PLoS One 2019; 14:e0226113. [PMID: 31891593 PMCID: PMC6938330 DOI: 10.1371/journal.pone.0226113] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 11/19/2019] [Indexed: 01/26/2023] Open
Abstract
The Rho and Ras pathways play vital roles in cell growth, division and motility. Cross-talk between the pathways amplifies their roles in cell proliferation and motility and its dysregulation is involved in disease pathogenesis. One important interaction for cross-talk occurs between p120RasGAP (RASA1), a GTPase activating protein (GAP) for Ras, and p190RhoGAP (p190RhoGAP-A, ARHGAP35), a GAP for Rho. The binding of these proteins is primarily mediated by two SH2 domains within p120RasGAP engaging phosphorylated tyrosines of p190RhoGAP, of which the best studied is pTyr-1105. To better understand the interaction between p120RasGAP and p190RhoGAP, we determined the 1.75 Å X-ray crystal structure of the N-terminal SH2 domain of p120RasGAP in the unliganded form, and its 1.6 Å co-crystal structure in complex with a synthesized phosphotyrosine peptide, EEENI(p-Tyr)SVPHDST, corresponding to residues 1100–1112 of p190RhoGAP. We find that the N-terminal SH2 domain of p120RhoGAP has the characteristic SH2 fold encompassing a central beta-sheet flanked by two alpha-helices, and that peptide binding stabilizes specific conformations of the βE-βF loop and arginine residues R212 and R231. Site-directed mutagenesis and native gel shifts confirm phosphotyrosine binding through the conserved FLVR motif arginine residue R207, and isothermal titration calorimetry finds a dissociation constant of 0.3 ± 0.1 μM between the phosphopeptide and SH2 domain. These results demonstrate that the major interaction between two important GAP proteins, p120RasGAP and p190RhoGAP, is mediated by a canonical SH2-pTyr interaction.
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Affiliation(s)
- Rachel Jaber Chehayeb
- Yale College, New Haven, Connecticut, United States of America
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
| | - Amy L. Stiegler
- Department of Pharmacology, Yale University, New Haven, Connecticut, United States of America
| | - Titus J. Boggon
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut, United States of America
- Department of Pharmacology, Yale University, New Haven, Connecticut, United States of America
- Yale Cancer Center, Yale University, New Haven, Connecticut, United States of America
- * E-mail:
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6
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Donohue E, Khorsand S, Mercado G, Varney KM, Wilder PT, Yu W, MacKerell AD, Alexander P, Van QN, Moree B, Stephen AG, Weber DJ, Salafsky J, McCormick F. Second harmonic generation detection of Ras conformational changes and discovery of a small molecule binder. Proc Natl Acad Sci U S A 2019; 116:17290-17297. [PMID: 31399543 PMCID: PMC6717309 DOI: 10.1073/pnas.1905516116] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Second harmonic generation (SHG) is an emergent biophysical method that sensitively measures real-time conformational change of biomolecules in the presence of biological ligands and small molecules. This study describes the successful implementation of SHG as a primary screening platform to identify fragment ligands to oncogenic Kirsten rat sarcoma (KRas). KRas is the most frequently mutated driver of pancreatic, colon, and lung cancers; however, there are few well-characterized small molecule ligands due to a lack of deep binding pockets. Using SHG, we identified a fragment binder to KRasG12D and used 1H 15N transverse relaxation optimized spectroscopy (TROSY) heteronuclear single-quantum coherence (HSQC) NMR to characterize its binding site as a pocket adjacent to the switch 2 region. The unique sensitivity of SHG furthered our study by revealing distinct conformations induced by our hit fragment compared with 4,6-dichloro-2-methyl-3-aminoethyl-indole (DCAI), a Ras ligand previously described to bind the same pocket. This study highlights SHG as a high-throughput screening platform that reveals structural insights in addition to ligand binding.
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Affiliation(s)
- Elizabeth Donohue
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158
- Biodesy, Inc., South San Francisco, CA 94080
| | - Sina Khorsand
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158
- Biodesy, Inc., South San Francisco, CA 94080
| | | | - Kristen M Varney
- Center for Biomolecular Therapeutics, School of Medicine, University of Maryland, Baltimore, MD 21201
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland, Baltimore, MD 21201
| | - Paul T Wilder
- Center for Biomolecular Therapeutics, School of Medicine, University of Maryland, Baltimore, MD 21201
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland, Baltimore, MD 21201
| | - Wenbo Yu
- Center for Biomolecular Therapeutics, School of Medicine, University of Maryland, Baltimore, MD 21201
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201
| | - Alexander D MacKerell
- Center for Biomolecular Therapeutics, School of Medicine, University of Maryland, Baltimore, MD 21201
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland, Baltimore, MD 21201
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201
| | - Patrick Alexander
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Que N Van
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - Ben Moree
- Biodesy, Inc., South San Francisco, CA 94080
| | - Andrew G Stephen
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
| | - David J Weber
- Center for Biomolecular Therapeutics, School of Medicine, University of Maryland, Baltimore, MD 21201
- Department of Biochemistry and Molecular Biology, School of Medicine, University of Maryland, Baltimore, MD 21201
- Marlene and Stewart Greenebaum Comprehensive Cancer Center, University of Maryland, Baltimore, MD 21201
| | - Joshua Salafsky
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158
| | - Frank McCormick
- Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, CA 94158;
- National Cancer Institute RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Inc., Frederick, MD 21702
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7
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Abstract
Some 25 years ago, Raf was discovered as the transforming principle shared by a murine sarcoma and an avian carcinoma virus. Thus, Raf and tumorigenesis have been connected from the very beginning. Ten years later, the work of many groups instated Raf as the link between Ras, the oncogene most frequently mutated in human cancers, and the mitogen-activated protein kinase/extracellular signal-regulated kinase kinase (MEK/ERK) module, which with its manifold substrates can contribute to different aspects of carcinogenesis. Finally, the discovery of activating B-Raf mutations in a subset of human cancers, notably melanomas, conclusively established Raf as a major player in tumor development. Recent studies in animal models now show that endogenous C-Raf is essential for the development and maintenance of Ras-induced epidermal tumors. Surprisingly, the role of C-Raf in this case is not that of an mitogen-activated protein kinase activator, but rather that of an endogenous inhibitor of Rho signaling, expanding the range of tumor-related Raf targets. This review focuses on old and new targets of Raf in tumorigenesis.
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Affiliation(s)
- Théodora S Niault
- Center for Molecular Biology, Max F Perutz Laboratories, University of Vienna, Doktor-Bohr-Gasse 9, 1030 Vienna, Austria
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8
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Hahnel C, Gottmann K, Wittinghofer A, Lux HD. p21ras Oncogene Protein Selectively Increases Low-voltage-activated Ca2+ Current Density in Embryonic Chick Dorsal Root Ganglion Neurons. Eur J Neurosci 2002; 4:361-368. [PMID: 12106362 DOI: 10.1111/j.1460-9568.1992.tb00883.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
p21ras protein resembles the alpha subunit of trimeric G-proteins, which regulate ion channel function. We now report a modulation of Ca2+ channels in vertebrate sensory neurons by p21ras in addition to its role in cell growth and differentiation. Quantitative microinjection of oncogenic p21-H-ras into embryonic chick dorsal root ganglion neurons was performed. After 4 h the current density of the low-voltage-activated (LVA; T-type) Ca2+ channels was increased. However, in contrast to trimeric G-proteins, which inhibit high-voltage-activated (HVA) Ca2+ channels in chick dorsal root ganglion neurons, p21ras did not significantly affect HVA Ca2+ currents. To study the time course of p21ras action, guanosine triphosphate-preloaded p21ras was added to the patch pipette. Full-length ras was effective only after a delay of 20 - 30 min. C-terminal modification by cellular enzymes is required to activate full-length ras, and can account for the observed delay. Unexpectedly, C-terminal-truncated p21ras, which was found to be inactive in biological assays, enhanced LVA Ca2+ currents within minutes. This suggests a G-protein-like modulation of the LVA Ca2+ channel by p21ras. In an early phase of neuronal differentiation, dorsal root ganglion neurons express only LVA Ca2+ currents. The regulatory role of p21ras on LVA channels may therefore be particularly important during differentiation.
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Affiliation(s)
- C. Hahnel
- Department of Neurophysiology, Max Planck Institute for Psychiatry, Am Klopferspitz 18a, 8033 Planegg/Martinsried, FRG
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9
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Iyengar TD, Ng S, Lau CC, Welch WR, Bell DA, Berkowitz RS, Mok SC. Differential expression of NF1 type I and type II isoforms in sporadic borderline and invasive epithelial ovarian tumors. Oncogene 1999; 18:257-62. [PMID: 9926941 DOI: 10.1038/sj.onc.1202294] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The NF1 gene, a putative tumor suppressor gene, contains a GAP related domain (GRD) which accelerates hydrolysis of ras-bound GTP to GDP, thereby converting the ras oncogene from its active to inactive form. Two forms of the NF1 GRD transcript (Type I and Type II) are differentially expressed in neuroectodermal tumor tissue relative to differentiated neural cells, and in gastric cancer cell lines relative to normal stomach mucosa. We measured relative expression of NF1 Type II and Type I isoforms in cultured normal and malignant human ovarian surface epithelial cells(HOSE) and in invasive and borderline ovarian tumor tissue. We demonstrated an 11-fold increase in Type II:Type I ratio in 7 HOSE cultures relative to eight ovarian cancer cell lines. Our findings indicate a significant decrease in Type II isoform expression and increase in Type I expression in ovarian cancer cells and tumor tissue relative to HOSE cells. We also demonstrate an increase in Type II:Type I ratio, and a decrease in cell proliferation rate in three ovarian cancer cell lines on treatment with retinoic acid. We propose that differential expression of the NF1 Type I and Type II isoforms is related to cellular differentiation in ovarian epithelial cancer and strategies based on alteration in NF1 isoform expression may have therapeutic potential in ovarian malignancies.
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Affiliation(s)
- T D Iyengar
- University of Pennsylvania School of Medicine, Philadelphia 19104, USA
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10
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Poullet P, Créchet JB, Bernardi A, Parmeggiani A. Properties of the catalytic domain of sdc25p, a yeast GDP/GTP exchange factor of Ras proteins. Complexation with wild-type Ras2p, [S24N]Ras2p and [R80D, N81D]Ras2p. EUROPEAN JOURNAL OF BIOCHEMISTRY 1995; 227:537-44. [PMID: 7851434 DOI: 10.1111/j.1432-1033.1995.tb20421.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The catalytic domain of the Saccharomyces cerevisiae SDC25 gene product, including the last 550 C-terminal residues (Sdc25p-C), was produced as an Escherichia coli recombinant protein fused with glutathione S-transferase. The highly purified (greater than 95%) stable fusion protein, obtained by affinity chromatography, was very active in enhancing the dissociation rate or the GDP/GTP exchange of the GDP complex of Ras2p or human H-ras p21. This activity was further increased (three times) by glutathione S-transferase cleavage with thrombin. The stimulation of the guanine nucleotide release by Sdc25p-C was stronger for Ras2p.GDP than Ras2p.GTP, an effect that was less pronounced in the case of the p21 complexes. The association rate of the Ras2p.GDP (GTP) complex was also enhanced by Sdc25p-C. Monovalent and divalent salts inhibit the nucleotide-releasing activity of Sdc25p-C. Retention phenomena occurring on gel-filtration chromatography hindered the use of highly purified Sdc25p-C to study the formation of stable complexes with Ras2p. For this purpose, Sdc25p-C was produced as a non-glutathione-S-transferase fusion protein via pTTQ19. Upon partial purification, this product yielded a 54-kDa truncated form of Sdc25p-C (truncated Sdc25p-C) showing the same specific activity as the 64-kDa Sdc25p-C protein. On gel filtration, truncated Sdc25p-C and nucleotide-free Ras2p (or p21) formed a stable 1:1 stoichiometric complex that was dissociated by increasing concentrations of GDP. The properties of this complex were analyzed by using the mutant [S24N]Ras2p, the homologue of [S17N]p21 known to induce a dominant negative phenotype, [R80D, N81D]Ras2p, a recessive negative mutant insensitive to the truncated form of Sdc25p-C in vitro. The complex with [S24N]Ras2p was greater than 100-fold less sensitive to the dissociating effect of GDP, whereas [R80D, N81D]Ras2p was unable to form a stable complex with truncated Sdc25p-C. These results strongly suggest that the residues R80 and N81 are situated in or closely associated with the Ras2p specific site binding Sdc25p.
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Affiliation(s)
- P Poullet
- Structure Diverse d'Interventions no. 61840 du Centre National de la Recherche Scientifique, Laboratoire de Biochimie, Ecole Polytechnique, Palaiseau, France
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11
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Characterization of a 78-residue fragment of c-Raf-1 that comprises a minimal binding domain for the interaction with Ras-GTP. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)31795-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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12
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Polakis P, McCormick F. Structural requirements for the interaction of p21ras with GAP, exchange factors, and its biological effector target. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(18)98325-0] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
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13
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Wiesmüller L, Wittinghofer A. Expression of the GTPase activating domain of the neurofibromatosis type 1 (NF1) gene in Escherichia coli and role of the conserved lysine residue. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)50003-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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14
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Reinstein J, Schlichting I, Frech M, Goody R, Wittinghofer A. p21 with a phenylalanine 28—-leucine mutation reacts normally with the GTPase activating protein GAP but nevertheless has transforming properties. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(19)47428-0] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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15
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Valencia A, Kjeldgaard M, Pai EF, Sander C. GTPase domains of ras p21 oncogene protein and elongation factor Tu: analysis of three-dimensional structures, sequence families, and functional sites. Proc Natl Acad Sci U S A 1991; 88:5443-7. [PMID: 2052624 PMCID: PMC51889 DOI: 10.1073/pnas.88.12.5443] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
GTPase domains are functional and structural units employed as molecular switches in a variety of important cellular functions, such as growth control, protein biosynthesis, and membrane traffic. Amino acid sequences of more than 100 members of different subfamilies are known, but crystal structures of only mammalian ras p21 and bacterial elongation factor Tu have been determined. After optimal superposition of these remarkably similar structures, careful multiple sequence alignment, and calculation of residue-residue interactions, we analyzed the two subfamilies in terms of structural conservation, sequence conservation, and residue contact strength. There are three main results. (i) A structure-based alignment of p21 and elongation factor Tu. (ii) The definition of a common conserved structural core that may be useful as the basis of model building by homology of the three-dimensional structure of any GTPase domain. (iii) Identification of sequence regions, other than the effector loop and the nucleotide binding site, that may be involved in the functional cycle: they are loop L4, known to change conformation after GTP hydrolysis; helix alpha 2, especially Arg-73 and Met-67 in ras p21; loops L8 and L10, including ras p21 Arg-123, Lys-147, and Leu-120; and residues located spatially near the N and C termini. These regions are candidate sites for interaction either with the GTP/GDP exchange factor, with a GTPase-affected function, or with a molecule delivered to a destination site with the aid of the GTPase domain.
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Affiliation(s)
- A Valencia
- European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany
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16
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Purification, characterization, and western blot analysis of human GTPase-activating protein from native and recombinant sources. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(18)45826-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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