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Abstract
Despite over two decades of research, the mechanism of Rab targeting to specific intracellular membranes is still not completely understood. Present evidence suggests that the original hypothesis that the message for targeting resides solely in the hypervariable C-terminus is incorrect, and a second mechanism involving a GDF [GDI (guanine-nucleotide-dissociation inhibitor) displacement factor] to disrupt stable Rab–GDI complexes has only been shown to apply in one case, despite the need for targeting over 60 human Rab proteins. Evidence for the involvement of Rab–effector interactions has only been presented for a few cases or in a very specific context. There is mounting evidence that GEFs (guanine-nucleotide-exchange factors) are essential for membrane targeting, although contributions from additional factors are likely to be of importance, at least in specific cases.
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2
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Heo JB, Yi YB, Bahk JD. Rice GDP dissociation inhibitor 3 inhibits OsMAPK2 activity through physical interaction. Biochem Biophys Res Commun 2011; 414:814-9. [PMID: 22020099 DOI: 10.1016/j.bbrc.2011.10.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 10/06/2011] [Indexed: 10/16/2022]
Abstract
GDP dissociation inhibitor (GDI) plays an essential role in regulating the state of bound nucleotides and subcellular localizations of Rab proteins. In our previous study, we showed that OsGDI3 facilitates the recycling of OsRab11 with a help of OsGAP1. In this study, we show that OsGDI3 complement the yeast sec19-1 mutant, a temperature-sensitive allele of the yeast GDI gene, suggesting that OsGDI3 is a functional ortholog of yeast GDI. To obtain further knowledge on the function of OsGDI3, candidate OsGDI3-interacting proteins were identified by yeast two-hybrid screens. OsMAPK2 is one of OsGDI3 interacting proteins from yeast two-hybrid screens and subject to further analysis. A kinase assay showed that the autophosphorylation activity of OsMAPK2 is inhibited by OsGDI3 in vitro. In addition, ectopic expressions of OsGDI3-in Arabidopsis cause reductions at the level of phosphorylated AtMPK in phosphorylation activity. Taken together, OsGDI3 functions as a negative regulator of OsMAPK2 through modulating its kinase activity.
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Affiliation(s)
- Jae Bok Heo
- Department of Molecular Biotechnology, Dong-A University, Busan 604-714, Republic of Korea
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3
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Young ARJ, Chan EYW, Hu XW, Köchl R, Crawshaw SG, High S, Hailey DW, Lippincott-Schwartz J, Tooze SA. Starvation and ULK1-dependent cycling of mammalian Atg9 between the TGN and endosomes. J Cell Sci 2006; 119:3888-900. [PMID: 16940348 DOI: 10.1242/jcs.03172] [Citation(s) in RCA: 607] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Autophagy, fundamentally a lysosomal degradation pathway, functions in cells during normal growth and certain pathological conditions, including starvation, to maintain homeostasis. Autophagosomes are formed through a mechanism that is not well understood, despite the identification of many genes required for autophagy. We have studied the mammalian homologue of Atg9p, a multi-spanning transmembrane protein essential in yeast for autophagy, to gain a better understanding of the function of this ubiquitious protein. We show that both the N- and C-termini of mammalian Atg9 (mAtg9) are cytosolic, and predict that mAtg9 spans the membrane six times. We find that mAtg9 is located in the trans-Golgi network and late endosomes and colocalizes with TGN46, the cation-independent mannose-6-phosphate receptor, Rab7 and Rab9. Amino acid starvation or rapamycin treatment, which upregulates autophagy, causes a redistribution of mAtg9 from the TGN to peripheral, endosomal membranes, which are positive for the autophagosomal marker GFP-LC3. siRNA-mediated depletion of the putative mammalian homologue of Atg1p, ULK1, inhibits this starvation-induced redistribution. The redistribution of mAtg9 also requires PI 3-kinase activity, and is reversed after restoration of amino acids. We speculate that starvation-induced autophagy, which requires mAtg9, may rely on an alteration of the steady-state trafficking of mAtg9, in a Atg1-dependent manner.
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Affiliation(s)
- Andrew R J Young
- Cancer Research UK London Research Institute, 44 Lincoln's Inn Fields, London, WC2A 3PX, UK
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4
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Ricard CS, Jakubowski JM, Verbsky JW, Barbieri MA, Lewis WM, Fernandez GE, Vogel M, Tsou C, Prasad V, Stahl PD, Waksman G, Cheney CM. Drosophila rab GDI mutants disrupt development but have normal Rab membrane extraction. Genesis 2001; 31:17-29. [PMID: 11668674 DOI: 10.1002/gene.10000] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Rab GTPases are essential for vesicular transport. Rab GDP dissociation inhibitor (GDI) binds to GDP-bound rabs, removes rabs from acceptor membranes and delivers rabs to donor membranes. We isolated lethal GDI mutations in Drosophila and analyzed their developmental phenotypes. To learn how these mutations affect GDI structure, the crystal structure of Drosophila GDI was determined by molecular replacement to a resolution of 3.0 A. Two hypomorphic, missense mutations are located in domain II of GDI at highly conserved positions, but not in previously identified sequence conserved regions. The mutant GDIs were tested for ability to extract rabs from membranes and showed wild-type levels of rab membrane extraction. The two missense alleles showed intragenic complementation, indicating that domain II of GDI may have two separable functions. This study indicates that GDI function is essential for development of a complex, multicellular organism and that puparium formation and pole cell formation are especially dependent on GDI function.
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Affiliation(s)
- C S Ricard
- Department of Biochemistry and Molecular Biophysics, Washington University School of Medicine, St. Louis, Missouri, USA
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5
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Huang CF, Chuang NN. Facilitated geranylgeranylation of shrimp ras-encoded p25 fusion protein by the binding with guanosine diphosphate. ACTA ACUST UNITED AC 1999. [DOI: 10.1002/(sici)1097-010x(19990501)283:6<510::aid-jez2>3.0.co;2-d] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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6
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Hori Y, Takeyama Y, Hiroyoshi M, Ueda T, Maeda A, Ohyanagi H, Saitoh Y, Kaibuchi K, Takai Y. Possible involvement of Rab11 p24, a Ras-like small GTP-binding protein, in intracellular vesicular transport of isolated pancreatic acini. Dig Dis Sci 1996; 41:133-8. [PMID: 8565746 DOI: 10.1007/bf02208595] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Rab11 p24 is a Ras-like small guanosine triphosphate (GTP)-binding protein, and specific antibodies against it were newly developed to explore its function. Using the antibody, Rab11 p24 was shown to be abundant in rat pancreas as well as in most rat tissues. To explore the involvement of Rab11 p24 into the exocytotic process, the subcellular distribution of Rab11 p24 in rat pancreatic acini was evaluated also by use of the antibody. When the isolated acini were incubated with 1 x 10(-10) M cholecystokinin octapeptide (CCK-8) that induced the maximal stimulation, the amount of Rab11 p24 increased in the fractions of plasma membrane and zymogen granules, but decreased in the cytosol fraction. This redistribution was time-dependent and occurred within 1 min after the CCK-8 stimulation and reached a maximal level within 2 min after the stimulation. Moreover, a light microscopic immunolabeling technique on the isolated rat pancreatic acini also revealed that higher immunoreactivity with Rab11 p24 was observed over the zymogen granule membrane under CCK-8 stimulation. The present results indicate that Rab11 p24 is translocated from cytosol to the membrane fraction during stimulation with CCK-8 and suggest that Rab11 p24 is involved in the intracellular vesicular transport of isolated acini.
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Affiliation(s)
- Y Hori
- First Department of Surgery, Kobe University School of Medicine, Japan
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7
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Pfeffer SR, Dirac-Svejstrup AB, Soldati T. Rab GDP dissociation inhibitor: putting rab GTPases in the right place. J Biol Chem 1995; 270:17057-9. [PMID: 7615494 DOI: 10.1074/jbc.270.29.17057] [Citation(s) in RCA: 198] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- S R Pfeffer
- Department of Biochemistry, Stanford University School of Medicine, California 94305-5307, USA
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8
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Ullrich O, Horiuchi H, Alexandrov K, Zerial M. Use of Rab-GDP dissociation inhibitor for solubilization and delivery of Rab proteins to biological membranes in streptolysin O-permeabilized cells. Methods Enzymol 1995; 257:243-53. [PMID: 8583927 DOI: 10.1016/s0076-6879(95)57029-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- O Ullrich
- Cell Biology Program, European Molecular Biology Laboratory, Heidelberg, Germany
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9
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Affiliation(s)
- T Sasaki
- Department of Molecular Biology and Biochemistry, Osaka University Medical School, Suita, Japan
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10
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Yang C, Slepnev V, Goud B. Rab proteins form in vivo complexes with two isoforms of the GDP-dissociation inhibitor protein (GDI). J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)31779-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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11
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Sedlacek Z, Konecki DS, Korn B, Klauck SM, Poustka A. Evolutionary conservation and genomic organization of XAP-4, an Xq28 located gene coding for a human rab GDP-dissociation inhibitor (GDI). Mamm Genome 1994; 5:633-9. [PMID: 7849400 DOI: 10.1007/bf00411459] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
After the development of efficient methods for the construction of transcription maps of defined genomic regions, the rate-limiting step in the analysis of the coding potentials of these regions is the elucidation of function of the novel genes and the examination of their possible involvement in hereditary diseases localized to the region. This can be greatly facilitated by the detection of sequence homology to a gene of known function. XAP-4 is one of the genes identified in the G6PD region of the human Xq28 by direct cDNA selection. The rapid assembly of this gene and the determination of its function was possible because of its sequence homology with the bovine smg p25A/rab3A GDP dissociation inhibitor (GDI). Sequence comparison with other GDIs in the databases has revealed that XAP-4 belongs to one of at least two distinct classes of mammalian rab GDIs. The rab GDIs, which play an important role in the regulation of cellular transport, are highly evolutionarily conserved, as are several other genes identified in the neighborhood of XAP-4. This genomic region is very gene dense, and all the cDNA clones from the approximately 2.5-kb-long transcript of XAP-4 map to a single 7.5-kb genomic EcoRI fragment. The genomic organization of XAP-4 has been examined to determine the distribution of the exonic sequences within this short segment of genomic DNA. It was found that, similar to several other genes from the region, XAP-4 is split into exons of average size, which are interrupted by very short introns.
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Affiliation(s)
- Z Sedlacek
- Deutsches Krebsforschungszentrum, Heidelberg, Germany
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12
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Peter F, Nuoffer C, Pind SN, Balch WE. Guanine nucleotide dissociation inhibitor is essential for Rab1 function in budding from the endoplasmic reticulum and transport through the Golgi stack. J Biophys Biochem Cytol 1994; 126:1393-406. [PMID: 8089173 PMCID: PMC2290957 DOI: 10.1083/jcb.126.6.1393] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The small GTPase Rab1 is required for vesicular traffic from the ER to the cis-Golgi compartment, and for transport between the cis and medial compartments of the Golgi stack. In the present study, we examine the role of guanine nucleotide dissociation inhibitor (GDI) in regulating the function of Rab1 in the transport of vesicular stomatitis virus glycoprotein (VSV-G) in vitro. Incubation in the presence of excess GDI rapidly (t1/2 < 30 s) extracted Rab1 from membranes, inhibiting vesicle budding from the ER and sequential transport between the cis-, medial-, and trans-Golgi cisternae. These results demonstrate a direct role for GDI in the recycling of Rab proteins. Analysis of rat liver cytosol by gel filtration revealed that a major pool of Rab1 fractionates with a molecular mass of approximately 80 kD in the form of a GDI-Rab1 complex. When the GDI-Rab1 complex was depleted from cytosol by use of a Rab1-specific antibody, VSV-G failed to exit the ER. However, supplementation of depleted cytosol with a GDI-Rab1 complex prepared in vitro from recombinant forms of Rab1 and GDI efficiently restored export from the ER, and transport through the Golgi stack. These results provide evidence that a cytosolic GDI-Rab1 complex is required for the formation of non-clathrin-coated vesicles mediating transport through the secretory pathway.
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Affiliation(s)
- F Peter
- Department of Cell Biology, Scripps Research Institute, La Jolla, California 92037
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13
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Cloning, characterization, and expression of a novel GDP dissociation inhibitor isoform from skeletal muscle. Mol Cell Biol 1994. [PMID: 7513052 DOI: 10.1128/mcb.14.5.3459] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cellular mechanisms for controlling membrane trafficking appear to involve small GTP-binding proteins such as the Rab proteins. Rab function is regulated by GDP dissociation inhibitor (GDI), which releases Rab proteins from membranes and inhibits GDP dissociation. Here we report the isolation of a full-length cDNA encoding a novel GDI isoform of 445 amino acids (GDI-2) with a deduced molecular weight of 50,649 from mouse skeletal muscle. Full-length and partial cDNA clones encoding a previously reported GDI protein (GDI-1) were also isolated from cDNA libraries prepared from rat brain and mouse skeletal muscle, respectively. The degree of deduced amino acid sequence identity between mouse GDI-2 and our mouse GDI-1 cDNA clone is 86%. Northern (RNA blot) analysis revealed that in human tissues, both GDI-1 and GDI-2 transcripts were abundant in brain, skeletal muscle, and pancreas but were weakly expressed in heart and liver. GDI-1 mRNA was expressed in kidney, whereas GDI-2 was almost absent, while in lung the relative amounts of these mRNA species were reversed. Specific antibodies against mouse GDI-1 and GDI-2 based on unique peptide sequences in the proteins were raised. Differentiation of 3T3-L1 fibroblasts into highly insulin-responsive adipocytes was accompanied by large increases in both mRNA and protein levels of GDI-1 and GDI-2. GDI-1 and GDI-2 expressed as glutathione S-transferase fusion proteins were both able to solubilize the membrane-bound forms of Rab4 and Rab5 in a GDP/GTP-dependent manner. Taken together, these data demonstrate that the protein products of at least two genes regulate the membrane dynamics of Rab proteins in mice.
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14
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Nishimura N, Nakamura H, Takai Y, Sano K. Molecular cloning and characterization of two rab GDI species from rat brain: brain-specific and ubiquitous types. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36773-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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15
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Shisheva A, Südhof TC, Czech MP. Cloning, characterization, and expression of a novel GDP dissociation inhibitor isoform from skeletal muscle. Mol Cell Biol 1994; 14:3459-68. [PMID: 7513052 PMCID: PMC358710 DOI: 10.1128/mcb.14.5.3459-3468.1994] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Cellular mechanisms for controlling membrane trafficking appear to involve small GTP-binding proteins such as the Rab proteins. Rab function is regulated by GDP dissociation inhibitor (GDI), which releases Rab proteins from membranes and inhibits GDP dissociation. Here we report the isolation of a full-length cDNA encoding a novel GDI isoform of 445 amino acids (GDI-2) with a deduced molecular weight of 50,649 from mouse skeletal muscle. Full-length and partial cDNA clones encoding a previously reported GDI protein (GDI-1) were also isolated from cDNA libraries prepared from rat brain and mouse skeletal muscle, respectively. The degree of deduced amino acid sequence identity between mouse GDI-2 and our mouse GDI-1 cDNA clone is 86%. Northern (RNA blot) analysis revealed that in human tissues, both GDI-1 and GDI-2 transcripts were abundant in brain, skeletal muscle, and pancreas but were weakly expressed in heart and liver. GDI-1 mRNA was expressed in kidney, whereas GDI-2 was almost absent, while in lung the relative amounts of these mRNA species were reversed. Specific antibodies against mouse GDI-1 and GDI-2 based on unique peptide sequences in the proteins were raised. Differentiation of 3T3-L1 fibroblasts into highly insulin-responsive adipocytes was accompanied by large increases in both mRNA and protein levels of GDI-1 and GDI-2. GDI-1 and GDI-2 expressed as glutathione S-transferase fusion proteins were both able to solubilize the membrane-bound forms of Rab4 and Rab5 in a GDP/GTP-dependent manner. Taken together, these data demonstrate that the protein products of at least two genes regulate the membrane dynamics of Rab proteins in mice.
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Affiliation(s)
- A Shisheva
- Program in Molecular Medicine, University of Massachusetts Medical Center, Worcester 01605
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16
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Garrett MD, Zahner JE, Cheney CM, Novick PJ. GDI1 encodes a GDP dissociation inhibitor that plays an essential role in the yeast secretory pathway. EMBO J 1994; 13:1718-28. [PMID: 8157010 PMCID: PMC395005 DOI: 10.1002/j.1460-2075.1994.tb06436.x] [Citation(s) in RCA: 143] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
GTP binding proteins of the Sec4/Ypt/rab family regulate distinct vesicular traffic events in eukaryotic cells. We have cloned GDI1, an essential homolog of bovine rab GDI (GDP dissociation inhibitor) from the yeast Saccharomyces cerevisiae. Analogous to the bovine protein, purified Gdi1p slows the dissociation of GDP from Sec4p and releases the GDP-bound form from yeast membranes. Depletion of Gdi1p in vivo leads to loss of the soluble pool of Sec4p and inhibition of protein transport at multiple stages of the secretory pathway. Complementation analysis indicates that GDI1 is allelic to sec19-1. These results establish that Gdi1p plays an essential function in membrane traffic and are consistent with a role for Gdi1p in the recycling of proteins of the Sec4/Ypt/rab family from their target membranes back to their vesicular pools.
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Affiliation(s)
- M D Garrett
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510
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17
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Elazar Z, Mayer T, Rothman J. Removal of Rab GTP-binding proteins from Golgi membranes by GDP dissociation inhibitor inhibits inter-cisternal transport in the Golgi stacks. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)42177-6] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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18
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Yamaguchi T, Shirataki H, Kishida S, Miyazaki M, Nishikawa J, Wada K, Numata S, Kaibuchi K, Takai Y. Two functionally different domains of rabphilin-3A, Rab3A p25/smg p25A-binding and phospholipid- and Ca(2+)-binding domains. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(19)74232-x] [Citation(s) in RCA: 105] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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19
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Roa M, Cornet V, Yang CZ, Goud B. The small GTP-binding protein rab6p is redistributed in the cytosol by brefeldin A. J Cell Sci 1993; 106 ( Pt 3):789-802. [PMID: 8308062 DOI: 10.1242/jcs.106.3.789] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Rab6 protein belongs to the Sec4/Ypt/rab subfamily of small GTP-binding proteins involved in intracellular membrane trafficking in yeast and mammalian cells. Its localization both in medial and trans-Golgi network prompted us to study the effects of brefeldin A (BFA) on rab6p redistribution. By two techniques, indirect immunofluorescence and cell fractionation, we investigated the fate of rab6p and compared it to other Golgi or trans-Golgi network markers in BHK-21 and NIH-3T3 cells. BFA, at 5 micrograms/ml, induced redistribution of rab6p according to a biphasic process: during the first 10–15 minutes, tubulo-vesicular structures--colabelled with a bona fide medial Golgi marker called CTR 433--were observed; these structures were then replaced by punctate diffuse staining, which was stable for up to 3 hours. The 110 kDa peripheral membrane protein beta-COP was released much more rapidly from the Golgi membranes, whereas the trans-Golgi network marker TGN 38 relocated to the microtubule organizing center. The kinetics of reversion of BFA action on these antigens was also followed by immunofluorescence. Consistent with these results, rab6 antigen, originally found as 40% in the cytosolic versus 60% in the particulate (P 150,000 g) fraction, became almost entirely cytosolic; moreover, it partitioned in the aqueous phase of Triton X-114 whereas the membrane fraction was detergent-soluble. Rab6p did not become part of the coatomers after its BFA-induced release from Golgi structures. Three requirements seemed to be necessary for such a release: integrity of the microtubules, presence of energy, and a hypothetical trimeric G protein, as revealed by the respective roles of nocodazole, ATP depletion, and sensitivity to aluminium fluoride. Finally, we have shown that BFA does not prevent attachment of newly synthesized rab6p to membranes.
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Affiliation(s)
- M Roa
- Unité de Génétique Somatique (URA CNRS 361), Institut Pasteur, Paris, France
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20
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Garrett MD, Kabcenell AK, Zahner JE, Kaibuchi K, Sasaki T, Takai Y, Cheney CM, Novick PJ. Interaction of Sec4 with GDI proteins from bovine brain, Drosophila melanogaster and Saccharomyces cerevisiae. Conservation of GDI membrane dissociation activity. FEBS Lett 1993; 331:233-8. [PMID: 8375508 DOI: 10.1016/0014-5793(93)80343-s] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Rab GDP dissociation inhibitor (Rab GDI), will induce the dissociation of GDP-bound rab3A from synaptic membranes and will inhibit GDP dissociation from Sec4, a member of the Rab subgroup of the Ras GTPase superfamily which is required for exocytosis in Saccharomyces cerevisiae. We report that Rab GDI releases GDP-bound Sec4 from yeast membranes. dGDI, a Drosophila homologue can similarly inhibit GDP dissociation from Sec4 and release GDP-bound Sec4 from yeast membranes. An activity partially purified from yeast cytosol dissociates GDP-bound Sec4 from yeast membranes, suggesting that yeast also possess a GDI protein that functions to recycle Sec4 from its target membrane.
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Affiliation(s)
- M D Garrett
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510
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21
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Abstract
Rab proteins are small GTPases highly related to the yeast Ypt1 and Sec4 proteins involved in secretion. The Rab proteins were found associated with membranes of different compartments along the secretory and endocytic pathways. They share distinct C-terminal cysteine motifs required for membrane association. Unlike the other Rab proteins, Rab8, Rab11 and Rab13 terminate with a C-terminal CaaX motif similar to those of Ras/Rho proteins. This report demonstrates that Rab8 and Rab13 proteins are isoprenylated in vivo and geranylgeranylated in vitro. Rab11 associates in vitro geranylgeranylpyrophosphate and farnesylpyrophosphate. Our study shows that the CaaX motif is required for isoprenylation.
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Affiliation(s)
- G Joberty
- INSERM U248, Faculté de médecine Lariboisière Saint Louis, Paris, France
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22
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Rab GDP dissociation inhibitor as a general regulator for the membrane association of rab proteins. J Biol Chem 1993. [DOI: 10.1016/s0021-9258(17)46822-0] [Citation(s) in RCA: 223] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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23
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Motoike T, Sano K, Nakamura H, Takai Y. Expression of smg p25A/rab 3A guanine nucleotide dissociation inhibitor (GDI) in neurons and glial cells from rat brain. Neurosci Lett 1993; 156:87-90. [PMID: 8414196 DOI: 10.1016/0304-3940(93)90446-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
smg p25A/rab 3A is a member of the rab family of small guanosine 5'-trisphosphate (GTP)-binding proteins, which are postulated to act as specific regulators of membrane trafficking in exocytosis and endocytosis. In neural tissues, smg p25A/rab 3A is expressed only in neurons but not in glia. In this study, expression of a regulatory protein for smg p25A/rab 3A, guanine nucleotide dissociation inhibitor (smg p25A/rab 3A GDI), in neurons and glia isolated from rat brain was examined. The smg p25A/rab 3A GDI mRNa was detected as early as on gestational day 14 in the fetal brain, and its level reached a maximum 5 days after birth. By immunoblot analysis, smg p25A/rab 3A GDI was detected in the homogenate of rat hippocampus as well as in that of astrocytes in primary culture. By immunocytochemical analysis, the smg p25A/rab 3A GDI immunoreactivity was detected in hippocampal neurons and oligodendrocytes. The immunoreactivity of astrocytes was much lower than that of neurons and oligodendrocytes. These results indicate that smg p25A/rab 3A GDI may play a fundamental role in membrane trafficking both neurons and glia by interacting with multiple rab family proteins.
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Affiliation(s)
- T Motoike
- Department of Pediatrics, Kobe University School of Medicine, Japan
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24
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Rabphilin-3A, a putative target protein for smg p25A/rab3A p25 small GTP-binding protein related to synaptotagmin. Mol Cell Biol 1993. [PMID: 8384302 DOI: 10.1128/mcb.13.4.2061] [Citation(s) in RCA: 293] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In a previous study (H. Shirataki, K. Kaibuchi, T. Yamaguchi, K. Wada, H. Horiuchi, and Y. Takai, J. Biol. Chem. 267:10946-10949, 1992), we highly purified from bovine brain crude membranes the putative target protein for smg p25A/rab3A p25, a ras p21-related small GTP-binding protein implicated in neurotransmitter release. In this study, we have isolated and sequenced the cDNA of this protein from a bovine brain cDNA library. The cDNA had an open reading frame encoding a protein of 704 amino acids with a calculated M(r) of 77,976. We tentatively refer to this protein as rabphilin-3A. Structural analysis of rabphilin-3A revealed the existence of two copies of an internal repeat that were homologous to the C2 domain of protein kinase C as described for synaptotagmin, which is known to be localized in the membrane of the synaptic vesicle and to bind to membrane phospholipid in a Ca(2+)-dependent manner. The isolated cDNA was expressed in COS7 cells, and the encoded protein was recognized with an anti-rabphilin-3A polyclonal antibody and was identical in size with rabphilin-3A purified from bovine brain by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Moreover, both rabphilin-3A purified from bovine brain and recombinant rabphilin-3A made a complex with the GTP gamma S-bound form of rab3A p25 but not with the GDP-bound form of rab3A p25. Immunoblot and Northern (RNA) blot analyses showed that rabphilin-3A was highly expressed in bovine and rat brains. These results indicate that rabphilin-3A is a novel protein that has C2 domains and selectively interacts with the GTP-bound form of rab3A p25.
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Shirataki H, Kaibuchi K, Sakoda T, Kishida S, Yamaguchi T, Wada K, Miyazaki M, Takai Y. Rabphilin-3A, a putative target protein for smg p25A/rab3A p25 small GTP-binding protein related to synaptotagmin. Mol Cell Biol 1993; 13:2061-8. [PMID: 8384302 PMCID: PMC359527 DOI: 10.1128/mcb.13.4.2061-2068.1993] [Citation(s) in RCA: 82] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In a previous study (H. Shirataki, K. Kaibuchi, T. Yamaguchi, K. Wada, H. Horiuchi, and Y. Takai, J. Biol. Chem. 267:10946-10949, 1992), we highly purified from bovine brain crude membranes the putative target protein for smg p25A/rab3A p25, a ras p21-related small GTP-binding protein implicated in neurotransmitter release. In this study, we have isolated and sequenced the cDNA of this protein from a bovine brain cDNA library. The cDNA had an open reading frame encoding a protein of 704 amino acids with a calculated M(r) of 77,976. We tentatively refer to this protein as rabphilin-3A. Structural analysis of rabphilin-3A revealed the existence of two copies of an internal repeat that were homologous to the C2 domain of protein kinase C as described for synaptotagmin, which is known to be localized in the membrane of the synaptic vesicle and to bind to membrane phospholipid in a Ca(2+)-dependent manner. The isolated cDNA was expressed in COS7 cells, and the encoded protein was recognized with an anti-rabphilin-3A polyclonal antibody and was identical in size with rabphilin-3A purified from bovine brain by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Moreover, both rabphilin-3A purified from bovine brain and recombinant rabphilin-3A made a complex with the GTP gamma S-bound form of rab3A p25 but not with the GDP-bound form of rab3A p25. Immunoblot and Northern (RNA) blot analyses showed that rabphilin-3A was highly expressed in bovine and rat brains. These results indicate that rabphilin-3A is a novel protein that has C2 domains and selectively interacts with the GTP-bound form of rab3A p25.
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Affiliation(s)
- H Shirataki
- Department of Cell Physiology, National Institute for Physiological Sciences, Okazaki, Japan
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26
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Soldati T, Riederer MA, Pfeffer SR. Rab GDI: a solubilizing and recycling factor for rab9 protein. Mol Biol Cell 1993; 4:425-34. [PMID: 8389620 PMCID: PMC300943 DOI: 10.1091/mbc.4.4.425] [Citation(s) in RCA: 137] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Rab proteins are thought to function in the processes by which transport vesicles identify and/or fuse with their respective target membranes. The bulk of these proteins are membrane associated, but a measurable fraction can be found in the cytosol. The cytosolic forms of rab3A, rab11, and Sec4 occur as equimolar complexes with a class of proteins termed "GDIs," or "GDP dissociation inhibitors." We show here that the cytosolic form of rab9, a protein required for transport between late endosomes and the trans Golgi network, also occurs as a complex with a GDI-like protein, with an apparent mass of approximately 80 kD. Complex formation could be reconstituted in vitro using recombinant rab9 protein, cytosol, ATP, and geranylgeranyl diphosphate, and was shown to require an intact rab9 carboxy terminus, as well as rab9 geranylgeranylation. Monoprenylation was sufficient for complex formation because a mutant rab9 protein bearing the carboxy terminal sequence, CLLL, was prenylated in vitro by geranylgeranyl transferase I and was efficiently incorporated into 80-kD complexes. Purified, prenylated rab9 could also assemble into 80-kD complexes by addition of purified, rab3A GDI. Finally, rab3A-GDI had the capacity to solubilize rab9GDP, but not rab9GTP, from cytoplasmic membranes. These findings support the proposal that GDI proteins serve to recycle rab proteins from their target membranes after completion of a rab protein-mediated, catalytic cycle. Thus GDI proteins have the potential to regulate the availability of specific intracellular transport factors.
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Affiliation(s)
- T Soldati
- Department of Biochemistry, Stanford University School of Medicine, California 94028
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27
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A Drosophila homolog of bovine smg p25a GDP dissociation inhibitor undergoes a shift in isoelectric point in the developmental mutant quartet. Mol Cell Biol 1993. [PMID: 8417327 DOI: 10.1128/mcb.13.1.217] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Drosophila developmental mutation quartet causes late larval lethality and small imaginal discs and, when expressed in the adult female, has a lethal effect on early embryogenesis. These developmental defects are associated with mitotic defects, which include a low mitotic index in larval brains and incomplete separation of chromosomes in mitosis in the early embryo. quartet mutations also have a biochemical effect, i.e., a basic shift in isoelectric point in three proteins. We have purified one of these proteins, raised an antibody to it, and isolated and sequenced its cDNA. At the amino acid level, the sequence shows 68% identity and 81% similarity to bovine smg p25a GDP dissociation inhibitor (GDI), a regulator of ras-like small GTPases of the rab/SEC4/YPT1 subfamily. The correlation between a basic shift in isoelectric point in Drosophila GDI in quartet mutant tissue and the quartet developmental phenotype raises the possibility that a posttranslational modification of GDI is necessary for its function and that GDI function is essential for development.
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28
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Zahner JE, Cheney CM. A Drosophila homolog of bovine smg p25a GDP dissociation inhibitor undergoes a shift in isoelectric point in the developmental mutant quartet. Mol Cell Biol 1993; 13:217-27. [PMID: 8417327 PMCID: PMC358901 DOI: 10.1128/mcb.13.1.217-227.1993] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The Drosophila developmental mutation quartet causes late larval lethality and small imaginal discs and, when expressed in the adult female, has a lethal effect on early embryogenesis. These developmental defects are associated with mitotic defects, which include a low mitotic index in larval brains and incomplete separation of chromosomes in mitosis in the early embryo. quartet mutations also have a biochemical effect, i.e., a basic shift in isoelectric point in three proteins. We have purified one of these proteins, raised an antibody to it, and isolated and sequenced its cDNA. At the amino acid level, the sequence shows 68% identity and 81% similarity to bovine smg p25a GDP dissociation inhibitor (GDI), a regulator of ras-like small GTPases of the rab/SEC4/YPT1 subfamily. The correlation between a basic shift in isoelectric point in Drosophila GDI in quartet mutant tissue and the quartet developmental phenotype raises the possibility that a posttranslational modification of GDI is necessary for its function and that GDI function is essential for development.
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Affiliation(s)
- J E Zahner
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri 63110
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29
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Farrell FX, Lapetina EG. Partial purification of a GTPase-activating protein for rap2b from bovine brain membranes. Biochem Biophys Res Commun 1992; 189:717-21. [PMID: 1472043 DOI: 10.1016/0006-291x(92)92260-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Rap2b is a ras-related GTP-binding protein isolated from a human platelet cDNA library. It shares 90% similarity to the previously described rap2a and is closely related to rap1a (Krev-1, smgp21), which has been shown to possess reversion of transformation activity in Kirsten ras transformed 3T3 cells. In this study we have partially purified a protein from bovine brain membranes which stimulates the GTPase activity of rap2b. This rap2b GTPase-activating protein (GAP) activity is not immunoreactive with antibodies specific for rap1 GAP or ras GAP, yet displays limited GTPase stimulatory activity toward rap1. This result differs from the previously described rap1 GAP which is highly specific for rap1. When the rap2 GAP activity is analyzed by coomassie staining, an enrichment of a approximately 55 kDa protein is observed providing further evidence of a distinct rap2 GAP.
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Affiliation(s)
- F X Farrell
- Division of Cell Biology, Burroughs Wellcome Co., Research Triangle Park, NC 27709
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30
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Regazzi R, Kikuchi A, Takai Y, Wollheim C. The small GTP-binding proteins in the cytosol of insulin-secreting cells are complexed to GDP dissociation inhibitor proteins. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)37072-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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31
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Pomerance M, Schweighoffer F, Tocque B, Pierre M. Stimulation of mitogen-activated protein kinase by oncogenic Ras p21 in Xenopus oocytes. Requirement for Ras p21-GTPase-activating protein interaction. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)41980-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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32
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Kikuchi A, Kuroda S, Sasaki T, Kotani K, Hirata K, Katayama M, Takai Y. Functional interactions of stimulatory and inhibitory GDP/GTP exchange proteins and their common substrate small GTP-binding protein. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42085-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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33
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Kuroda S, Kikuchi A, Hirata K, Masuda T, Kishi K, Sasaki T, Takai Y. Cooperative function of rho GDS and rho GDI to regulate rho p21 activation in smooth muscle. Biochem Biophys Res Commun 1992; 185:473-80. [PMID: 1599487 DOI: 10.1016/s0006-291x(05)81009-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The GDP/GTP exchange reaction of rho p21, a member of ras p21-related small GTP-binding protein superfamily, is regulated by two stimulatory GDP/GTP exchange proteins (GEPs), named smg GDS and rho GDS, and by one inhibitory GEP, named rho GDI. In bovine aortic smooth muscle, rho GDS and rho GDI were major GEPs for rho p21, and the rho GDI activity on the GDP/GTP exchange reaction of rho p21 was stronger than the rho GDS activity in their simultaneous presence. Moreover, in the crude cytosol, the GDP-bound form of rho p21 was complexed with rho GDI but not with rho GDS. These results, together with our recent finding that rho p21 is involved in the vasoconstrictor-induced Ca2+ sensitization of smooth muscle contraction, suggest that there is some mechanism to release the inhibitory action of rho GDI and to make rho p21 sensitive to the stimulatory action of rho GDS, eventually leading to the rho p21 activation, in the signaling pathways of the vasoconstrictor receptors in smooth muscle.
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Affiliation(s)
- S Kuroda
- Department of Biochemistry, Kobe University School of Medicine, Japan
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34
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Hiraoka K, Kaibuchi K, Ando S, Musha T, Takaishi K, Mizuno T, Asada M, Ménard L, Tomhave E, Didsbury J. Both stimulatory and inhibitory GDP/GTP exchange proteins, smg GDS and rho GDI, are active on multiple small GTP-binding proteins. Biochem Biophys Res Commun 1992; 182:921-30. [PMID: 1734890 DOI: 10.1016/0006-291x(92)91820-g] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Six peaks of small GTP-binding proteins (G proteins) were separated by column chromatographies from the cytosol fraction of the differentiated HL-60 cells: two peaks of rho p21, one peak of smg/rap1 p21, two peaks of rac1 p21, and one peak of an unidentified small G protein with a Mr of about 20,000 (20 KG). smg GDS, previously thought to be a stimulatory GDP/GTP exchange protein for smg p21, Ki-ras p21, and rho p21, but not for Ha-ras p21 or smg p25A, was also active on rac1 p21. rho GDI, previously thought to be an inhibitory GDP/GTP exchange protein specific for rho p21, was also active on rac1 p21. These results indicate that both smg GDS and rho GDI are active on multiple small G proteins.
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Affiliation(s)
- K Hiraoka
- Department of Biochemistry, Kobe University School of Medicine, Japan
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35
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Takai Y, Kaibuchi K, Kikuchi A, Kawata M. Small GTP-binding proteins. INTERNATIONAL REVIEW OF CYTOLOGY 1992; 133:187-230. [PMID: 1577587 DOI: 10.1016/s0074-7696(08)61861-6] [Citation(s) in RCA: 275] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Y Takai
- Department of Biochemistry, Kobe University School of Medicine, Japan
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36
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Sakurada K, Uchida K, Yamaguchi K, Aisaka K, Ito S, Ohmori T, Takeyama Y, Ueda T, Hori Y, Ohyanagi H. Molecular cloning and characterization of a ras p21-like GTP-binding protein (24KG) from rat liver. Biochem Biophys Res Commun 1991; 177:1224-32. [PMID: 1711847 DOI: 10.1016/0006-291x(91)90672-t] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have isolated cDNA clones from a rat liver cDNA library that encode a ras p21-like small GTP-binding protein (24KG) which was purified from the microsomes-Golgi complex fraction of the rat liver. The cloning was accomplished using polymerase chain reaction amplified with a set of oligonucleotide primers which were designed from the partial amino acid sequences for 24KG. The cDNA contained an open reading frame encoding a 216 amino acid protein with a calculated Mr weight of 24,397. This Mr weight was similar to that of the purified 24KG estimated by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The sequence analysis of 24KG revealed that a 24KG cDNA is the rat counterpart of a rab11 cDNA cloned from a Madin-Darby canine kidney cell cDNA library. The 1.0-kilobase 24KG mRNA corresponding to the isolated cDNA was also detected in various rat tissues, such as brain, testis, spleen, and heart.
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Affiliation(s)
- K Sakurada
- Tokyo Research Laboratories, Kyowa Hakko Kogyo Co., Ltd., Japan
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37
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Evans T, Hart MJ, Cerione RA. The Ras superfamilies: regulatory proteins and post-translational modifications. Curr Opin Cell Biol 1991; 3:185-91. [PMID: 1909148 DOI: 10.1016/0955-0674(91)90137-n] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The Ras-like GTP-binding proteins comprise a large superfamily of proteins that play key roles in a wide variety of cellular activities, including cell growth, differentiation, secretion, and protein trafficking. During the past few years, it has become clear that these GTP-binding proteins are regulated by a variety of manners, including interactions with specific types of regulatory proteins and post-translational modification events.
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Affiliation(s)
- T Evans
- Department of Cell Biology, Genentech Inc., South San Francisco, California 94080
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