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. 1995 Sep 1;130(5):1051–1061. doi: 10.1083/jcb.130.5.1051

Requirement of nucleotide exchange factor for Ypt1 GTPase mediated protein transport

PMCID: PMC2120555  PMID: 7657691

Abstract

Small GTPases of the rab family are involved in the regulation of vesicular transport. It is believed that cycling between the GTP- and GDP-bound forms, and accessory factors regulating this cycling are crucial for rab function. However, an essential role for rab nucleotide exchange factors has not yet been demonstrated. In this report we show the requirement of nucleotide exchange factor activity for Ypt1 GTPase mediated protein transport. The Ypt1 protein, a member of the rab family, plays a role in targeting vesicles to the acceptor compartment and is essential for the first two steps of the yeast secretory pathway. We use two YPT1 dominant mutations that contain alterations in a highly conserved GTP-binding domain, N121I and D124N. YPT1-D124N is a novel mutation that encodes a protein with nucleotide specificity modified from guanine to xanthine. This provides a tool for the study of an individual rab GTPase in crude extracts: a xanthosine triphosphate (XTP)-dependent conditional dominant mutation. Both mutations confer growth inhibition and a block in protein secretion when expressed in vivo. The purified mutant proteins do not bind either GDP or GTP. Moreover, they completely inhibit the ability of the exchange factor to stimulate nucleotide exchange for wild type Ypt1 protein, and are potent inhibitors of ER to Golgi transport in vitro at the vesicle targeting step. The inhibitory effects of the Ypt1-D124N mutant protein on both nucleotide exchange activity and protein transport in vitro can be relieved by XTP, indicating that it is the nucleotide-free form of the mutant protein that is inhibitory. These results suggest that the dominant mutant proteins inhibit protein transport by sequestering the exchange factor from the wild type Ypt1 protein, and that this factor has an essential role in vesicular transport.

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Selected References

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  1. Araki S., Kikuchi A., Hata Y., Isomura M., Takai Y. Regulation of reversible binding of smg p25A, a ras p21-like GTP-binding protein, to synaptic plasma membranes and vesicles by its specific regulatory protein, GDP dissociation inhibitor. J Biol Chem. 1990 Aug 5;265(22):13007–13015. [PubMed] [Google Scholar]
  2. Bacon R. A., Salminen A., Ruohola H., Novick P., Ferro-Novick S. The GTP-binding protein Ypt1 is required for transport in vitro: the Golgi apparatus is defective in ypt1 mutants. J Cell Biol. 1989 Sep;109(3):1015–1022. doi: 10.1083/jcb.109.3.1015. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Baker D., Hicke L., Rexach M., Schleyer M., Schekman R. Reconstitution of SEC gene product-dependent intercompartmental protein transport. Cell. 1988 Jul 29;54(3):335–344. doi: 10.1016/0092-8674(88)90196-1. [DOI] [PubMed] [Google Scholar]
  4. Baker D., Wuestehube L., Schekman R., Botstein D., Segev N. GTP-binding Ypt1 protein and Ca2+ function independently in a cell-free protein transport reaction. Proc Natl Acad Sci U S A. 1990 Jan;87(1):355–359. doi: 10.1073/pnas.87.1.355. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Barlowe C., Schekman R. SEC12 encodes a guanine-nucleotide-exchange factor essential for transport vesicle budding from the ER. Nature. 1993 Sep 23;365(6444):347–349. doi: 10.1038/365347a0. [DOI] [PubMed] [Google Scholar]
  6. Becker D. M., Guarente L. High-efficiency transformation of yeast by electroporation. Methods Enzymol. 1991;194:182–187. doi: 10.1016/0076-6879(91)94015-5. [DOI] [PubMed] [Google Scholar]
  7. Boeke J. D., Trueheart J., Natsoulis G., Fink G. R. 5-Fluoroorotic acid as a selective agent in yeast molecular genetics. Methods Enzymol. 1987;154:164–175. doi: 10.1016/0076-6879(87)54076-9. [DOI] [PubMed] [Google Scholar]
  8. Boguski M. S., McCormick F. Proteins regulating Ras and its relatives. Nature. 1993 Dec 16;366(6456):643–654. doi: 10.1038/366643a0. [DOI] [PubMed] [Google Scholar]
  9. Bourne H. R. Do GTPases direct membrane traffic in secretion? Cell. 1988 Jun 3;53(5):669–671. doi: 10.1016/0092-8674(88)90081-5. [DOI] [PubMed] [Google Scholar]
  10. Bourne H. R., Sanders D. A., McCormick F. The GTPase superfamily: a conserved switch for diverse cell functions. Nature. 1990 Nov 8;348(6297):125–132. doi: 10.1038/348125a0. [DOI] [PubMed] [Google Scholar]
  11. Bourne H. R., Sanders D. A., McCormick F. The GTPase superfamily: conserved structure and molecular mechanism. Nature. 1991 Jan 10;349(6305):117–127. doi: 10.1038/349117a0. [DOI] [PubMed] [Google Scholar]
  12. Broek D., Toda T., Michaeli T., Levin L., Birchmeier C., Zoller M., Powers S., Wigler M. The S. cerevisiae CDC25 gene product regulates the RAS/adenylate cyclase pathway. Cell. 1987 Mar 13;48(5):789–799. doi: 10.1016/0092-8674(87)90076-6. [DOI] [PubMed] [Google Scholar]
  13. Brondyk W. H., McKiernan C. J., Burstein E. S., Macara I. G. Mutants of Rab3A analogous to oncogenic Ras mutants. Sensitivity to Rab3A-GTPase activating protein and Rab3A-guanine nucleotide releasing factor. J Biol Chem. 1993 May 5;268(13):9410–9415. [PubMed] [Google Scholar]
  14. Bucci C., Parton R. G., Mather I. H., Stunnenberg H., Simons K., Hoflack B., Zerial M. The small GTPase rab5 functions as a regulatory factor in the early endocytic pathway. Cell. 1992 Sep 4;70(5):715–728. doi: 10.1016/0092-8674(92)90306-w. [DOI] [PubMed] [Google Scholar]
  15. Burstein E. S., Macara I. G. Characterization of a guanine nucleotide-releasing factor and a GTPase-activating protein that are specific for the ras-related protein p25rab3A. Proc Natl Acad Sci U S A. 1992 Feb 15;89(4):1154–1158. doi: 10.1073/pnas.89.4.1154. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Burton J. L., Burns M. E., Gatti E., Augustine G. J., De Camilli P. Specific interactions of Mss4 with members of the Rab GTPase subfamily. EMBO J. 1994 Dec 1;13(23):5547–5558. doi: 10.1002/j.1460-2075.1994.tb06892.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Burton J., Roberts D., Montaldi M., Novick P., De Camilli P. A mammalian guanine-nucleotide-releasing protein enhances function of yeast secretory protein Sec4. Nature. 1993 Feb 4;361(6411):464–467. doi: 10.1038/361464a0. [DOI] [PubMed] [Google Scholar]
  18. Chant J. Cell polarity in yeast. Trends Genet. 1994 Sep;10(9):328–333. doi: 10.1016/0168-9525(94)90036-1. [DOI] [PubMed] [Google Scholar]
  19. Clanton D. J., Hattori S., Shih T. Y. Mutations of the ras gene product p21 that abolish guanine nucleotide binding. Proc Natl Acad Sci U S A. 1986 Jul;83(14):5076–5080. doi: 10.1073/pnas.83.14.5076. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Corliss D. A., White W. E., Jr Fluorescence of yeast vitally stained with ethidium bromide and propidium iodide. J Histochem Cytochem. 1981 Jan;29(1):45–48. doi: 10.1177/29.1.6162881. [DOI] [PubMed] [Google Scholar]
  21. Der C. J., Finkel T., Cooper G. M. Biological and biochemical properties of human rasH genes mutated at codon 61. Cell. 1986 Jan 17;44(1):167–176. doi: 10.1016/0092-8674(86)90495-2. [DOI] [PubMed] [Google Scholar]
  22. Dirac-Svejstrup A. B., Soldati T., Shapiro A. D., Pfeffer S. R. Rab-GDI presents functional Rab9 to the intracellular transport machinery and contributes selectivity to Rab9 membrane recruitment. J Biol Chem. 1994 Jun 3;269(22):15427–15430. [PubMed] [Google Scholar]
  23. Dower W. J., Miller J. F., Ragsdale C. W. High efficiency transformation of E. coli by high voltage electroporation. Nucleic Acids Res. 1988 Jul 11;16(13):6127–6145. doi: 10.1093/nar/16.13.6127. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Feig L. A., Pan B. T., Roberts T. M., Cooper G. M. Isolation of ras GTP-binding mutants using an in situ colony-binding assay. Proc Natl Acad Sci U S A. 1986 Jul;83(13):4607–4611. doi: 10.1073/pnas.83.13.4607. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Ferro-Novick S., Novick P. The role of GTP-binding proteins in transport along the exocytic pathway. Annu Rev Cell Biol. 1993;9:575–599. doi: 10.1146/annurev.cb.09.110193.003043. [DOI] [PubMed] [Google Scholar]
  26. Gardner W. J., Woods R. A. Isolation and characterisation of guanine auxotrophs in Saccharomyces cerevisiae. Can J Microbiol. 1979 Mar;25(3):380–389. doi: 10.1139/m79-059. [DOI] [PubMed] [Google Scholar]
  27. Gorvel J. P., Chavrier P., Zerial M., Gruenberg J. rab5 controls early endosome fusion in vitro. Cell. 1991 Mar 8;64(5):915–925. doi: 10.1016/0092-8674(91)90316-q. [DOI] [PubMed] [Google Scholar]
  28. Graham T. R., Emr S. D. Compartmental organization of Golgi-specific protein modification and vacuolar protein sorting events defined in a yeast sec18 (NSF) mutant. J Cell Biol. 1991 Jul;114(2):207–218. doi: 10.1083/jcb.114.2.207. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Hakes D. J., Dixon J. E. New vectors for high level expression of recombinant proteins in bacteria. Anal Biochem. 1992 May 1;202(2):293–298. doi: 10.1016/0003-2697(92)90108-j. [DOI] [PubMed] [Google Scholar]
  30. Hall A., Self A. J. The effect of Mg2+ on the guanine nucleotide exchange rate of p21N-ras. J Biol Chem. 1986 Aug 25;261(24):10963–10965. [PubMed] [Google Scholar]
  31. Han M., Sternberg P. W. Analysis of dominant-negative mutations of the Caenorhabditis elegans let-60 ras gene. Genes Dev. 1991 Dec;5(12A):2188–2198. doi: 10.1101/gad.5.12a.2188. [DOI] [PubMed] [Google Scholar]
  32. Haney S. A., Broach J. R. Cdc25p, the guanine nucleotide exchange factor for the Ras proteins of Saccharomyces cerevisiae, promotes exchange by stabilizing Ras in a nucleotide-free state. J Biol Chem. 1994 Jun 17;269(24):16541–16548. [PubMed] [Google Scholar]
  33. Hoffman C. S., Winston F. A ten-minute DNA preparation from yeast efficiently releases autonomous plasmids for transformation of Escherichia coli. Gene. 1987;57(2-3):267–272. doi: 10.1016/0378-1119(87)90131-4. [DOI] [PubMed] [Google Scholar]
  34. Hwang Y. W., Miller D. L. A mutation that alters the nucleotide specificity of elongation factor Tu, a GTP regulatory protein. J Biol Chem. 1987 Sep 25;262(27):13081–13085. [PubMed] [Google Scholar]
  35. Hwang Y. W., Miller D. L. A study of the kinetic mechanism of elongation factor Ts. J Biol Chem. 1985 Sep 25;260(21):11498–11502. [PubMed] [Google Scholar]
  36. Hwang Y. W., Sanchez A., Miller D. L. Mutagenesis of bacterial elongation factor Tu at lysine 136. A conserved amino acid in GTP regulatory proteins. J Biol Chem. 1989 May 15;264(14):8304–8309. [PubMed] [Google Scholar]
  37. Hwang Y. W., Zhong J. M., Poullet P., Parmeggiani A. Inhibition of SDC25 C-domain-induced guanine-nucleotide exchange by guanine ring binding domain mutants of v-H-ras. J Biol Chem. 1993 Nov 25;268(33):24692–24698. [PubMed] [Google Scholar]
  38. Jamieson J. D., Palade G. E. Intracellular transport of secretory proteins in the pancreatic exocrine cell. I. Role of the peripheral elements of the Golgi complex. J Cell Biol. 1967 Aug;34(2):577–596. doi: 10.1083/jcb.34.2.577. [DOI] [PMC free article] [PubMed] [Google Scholar]
  39. Johnston M., Davis R. W. Sequences that regulate the divergent GAL1-GAL10 promoter in Saccharomyces cerevisiae. Mol Cell Biol. 1984 Aug;4(8):1440–1448. doi: 10.1128/mcb.4.8.1440. [DOI] [PMC free article] [PubMed] [Google Scholar]
  40. Kang C., Sun N., Honzatko R. B., Fromm H. J. Replacement of Asp333 with Asn by site-directed mutagenesis changes the substrate specificity of Escherichia coli adenylosuccinate synthetase from guanosine 5'-triphosphate to xanthosine 5'-triphosphate. J Biol Chem. 1994 Sep 30;269(39):24046–24049. [PubMed] [Google Scholar]
  41. Kaziro Y. The role of guanosine 5'-triphosphate in polypeptide chain elongation. Biochim Biophys Acta. 1978 Sep 21;505(1):95–127. doi: 10.1016/0304-4173(78)90009-5. [DOI] [PubMed] [Google Scholar]
  42. Kunkel T. A., Roberts J. D., Zakour R. A. Rapid and efficient site-specific mutagenesis without phenotypic selection. Methods Enzymol. 1987;154:367–382. doi: 10.1016/0076-6879(87)54085-x. [DOI] [PubMed] [Google Scholar]
  43. Laemmli U. K. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970 Aug 15;227(5259):680–685. doi: 10.1038/227680a0. [DOI] [PubMed] [Google Scholar]
  44. Lai C. C., Boguski M., Broek D., Powers S. Influence of guanine nucleotides on complex formation between Ras and CDC25 proteins. Mol Cell Biol. 1993 Mar;13(3):1345–1352. doi: 10.1128/mcb.13.3.1345. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Li G., Stahl P. D. Structure-function relationship of the small GTPase rab5. J Biol Chem. 1993 Nov 15;268(32):24475–24480. [PubMed] [Google Scholar]
  46. Lian J. P., Stone S., Jiang Y., Lyons P., Ferro-Novick S. Ypt1p implicated in v-SNARE activation. Nature. 1994 Dec 15;372(6507):698–701. doi: 10.1038/372698a0. [DOI] [PubMed] [Google Scholar]
  47. McCormick F., Levenson C., Cole G., Innis M., Clark R. Genetic and biochemical analysis of ras p21 structure. Symp Fundam Cancer Res. 1986;39:137–142. [PubMed] [Google Scholar]
  48. Miyazaki A., Sasaki T., Araki K., Ueno N., Imazumi K., Nagano F., Takahashi K., Takai Y. Comparison of kinetic properties between MSS4 and Rab3A GRF GDP/GTP exchange proteins. FEBS Lett. 1994 Aug 22;350(2-3):333–336. doi: 10.1016/0014-5793(94)00804-3. [DOI] [PubMed] [Google Scholar]
  49. Moya M., Roberts D., Novick P. DSS4-1 is a dominant suppressor of sec4-8 that encodes a nucleotide exchange protein that aids Sec4p function. Nature. 1993 Feb 4;361(6411):460–463. doi: 10.1038/361460a0. [DOI] [PubMed] [Google Scholar]
  50. Nuoffer C., Davidson H. W., Matteson J., Meinkoth J., Balch W. E. A GDP-bound of rab1 inhibits protein export from the endoplasmic reticulum and transport between Golgi compartments. J Cell Biol. 1994 Apr;125(2):225–237. doi: 10.1083/jcb.125.2.225. [DOI] [PMC free article] [PubMed] [Google Scholar]
  51. Palade G. Intracellular aspects of the process of protein synthesis. Science. 1975 Aug 1;189(4200):347–358. doi: 10.1126/science.1096303. [DOI] [PubMed] [Google Scholar]
  52. Pfeffer S. R., Rothman J. E. Biosynthetic protein transport and sorting by the endoplasmic reticulum and Golgi. Annu Rev Biochem. 1987;56:829–852. doi: 10.1146/annurev.bi.56.070187.004145. [DOI] [PubMed] [Google Scholar]
  53. Powers S., Gonzales E., Christensen T., Cubert J., Broek D. Functional cloning of BUD5, a CDC25-related gene from S. cerevisiae that can suppress a dominant-negative RAS2 mutant. Cell. 1991 Jun 28;65(7):1225–1231. doi: 10.1016/0092-8674(91)90017-s. [DOI] [PubMed] [Google Scholar]
  54. Powers S., O'Neill K., Wigler M. Dominant yeast and mammalian RAS mutants that interfere with the CDC25-dependent activation of wild-type RAS in Saccharomyces cerevisiae. Mol Cell Biol. 1989 Feb;9(2):390–395. doi: 10.1128/mcb.9.2.390. [DOI] [PMC free article] [PubMed] [Google Scholar]
  55. Regazzi R., Kikuchi A., Takai Y., Wollheim C. B. The small GTP-binding proteins in the cytosol of insulin-secreting cells are complexed to GDP dissociation inhibitor proteins. J Biol Chem. 1992 Sep 5;267(25):17512–17519. [PubMed] [Google Scholar]
  56. Rexach M. F., Schekman R. W. Distinct biochemical requirements for the budding, targeting, and fusion of ER-derived transport vesicles. J Cell Biol. 1991 Jul;114(2):219–229. doi: 10.1083/jcb.114.2.219. [DOI] [PMC free article] [PubMed] [Google Scholar]
  57. Riederer M. A., Soldati T., Shapiro A. D., Lin J., Pfeffer S. R. Lysosome biogenesis requires Rab9 function and receptor recycling from endosomes to the trans-Golgi network. J Cell Biol. 1994 May;125(3):573–582. doi: 10.1083/jcb.125.3.573. [DOI] [PMC free article] [PubMed] [Google Scholar]
  58. Robinson L. C., Gibbs J. B., Marshall M. S., Sigal I. S., Tatchell K. CDC25: a component of the RAS-adenylate cyclase pathway in Saccharomyces cerevisiae. Science. 1987 Mar 6;235(4793):1218–1221. doi: 10.1126/science.3547648. [DOI] [PubMed] [Google Scholar]
  59. Rothman J. E. Mechanisms of intracellular protein transport. Nature. 1994 Nov 3;372(6501):55–63. doi: 10.1038/372055a0. [DOI] [PubMed] [Google Scholar]
  60. Salminen A., Novick P. J. A ras-like protein is required for a post-Golgi event in yeast secretion. Cell. 1987 May 22;49(4):527–538. doi: 10.1016/0092-8674(87)90455-7. [DOI] [PubMed] [Google Scholar]
  61. Schmitt H. D., Wagner P., Pfaff E., Gallwitz D. The ras-related YPT1 gene product in yeast: a GTP-binding protein that might be involved in microtubule organization. Cell. 1986 Nov 7;47(3):401–412. doi: 10.1016/0092-8674(86)90597-0. [DOI] [PubMed] [Google Scholar]
  62. Segev N. Mediation of the attachment or fusion step in vesicular transport by the GTP-binding Ypt1 protein. Science. 1991 Jun 14;252(5012):1553–1556. doi: 10.1126/science.1904626. [DOI] [PubMed] [Google Scholar]
  63. Segev N., Mulholland J., Botstein D. The yeast GTP-binding YPT1 protein and a mammalian counterpart are associated with the secretion machinery. Cell. 1988 Mar 25;52(6):915–924. doi: 10.1016/0092-8674(88)90433-3. [DOI] [PubMed] [Google Scholar]
  64. Sikorski R. S., Hieter P. A system of shuttle vectors and yeast host strains designed for efficient manipulation of DNA in Saccharomyces cerevisiae. Genetics. 1989 May;122(1):19–27. doi: 10.1093/genetics/122.1.19. [DOI] [PMC free article] [PubMed] [Google Scholar]
  65. Smith D. B., Johnson K. S. Single-step purification of polypeptides expressed in Escherichia coli as fusions with glutathione S-transferase. Gene. 1988 Jul 15;67(1):31–40. doi: 10.1016/0378-1119(88)90005-4. [DOI] [PubMed] [Google Scholar]
  66. Soldati T., Riederer M. A., Pfeffer S. R. Rab GDI: a solubilizing and recycling factor for rab9 protein. Mol Biol Cell. 1993 Apr;4(4):425–434. doi: 10.1091/mbc.4.4.425. [DOI] [PMC free article] [PubMed] [Google Scholar]
  67. Soldati T., Shapiro A. D., Svejstrup A. B., Pfeffer S. R. Membrane targeting of the small GTPase Rab9 is accompanied by nucleotide exchange. Nature. 1994 May 5;369(6475):76–78. doi: 10.1038/369076a0. [DOI] [PubMed] [Google Scholar]
  68. Stenmark H., Parton R. G., Steele-Mortimer O., Lütcke A., Gruenberg J., Zerial M. Inhibition of rab5 GTPase activity stimulates membrane fusion in endocytosis. EMBO J. 1994 Mar 15;13(6):1287–1296. doi: 10.1002/j.1460-2075.1994.tb06381.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  69. Sunyer T., Codina J., Birnbaumer L. GTP hydrolysis by pure Ni, the inhibitory regulatory component of adenylyl cyclases. J Biol Chem. 1984 Dec 25;259(24):15447–15451. [PubMed] [Google Scholar]
  70. Søgaard M., Tani K., Ye R. R., Geromanos S., Tempst P., Kirchhausen T., Rothman J. E., Söllner T. A rab protein is required for the assembly of SNARE complexes in the docking of transport vesicles. Cell. 1994 Sep 23;78(6):937–948. doi: 10.1016/0092-8674(94)90270-4. [DOI] [PubMed] [Google Scholar]
  71. Tisdale E. J., Bourne J. R., Khosravi-Far R., Der C. J., Balch W. E. GTP-binding mutants of rab1 and rab2 are potent inhibitors of vesicular transport from the endoplasmic reticulum to the Golgi complex. J Cell Biol. 1992 Nov;119(4):749–761. doi: 10.1083/jcb.119.4.749. [DOI] [PMC free article] [PubMed] [Google Scholar]
  72. Ullrich O., Horiuchi H., Bucci C., Zerial M. Membrane association of Rab5 mediated by GDP-dissociation inhibitor and accompanied by GDP/GTP exchange. Nature. 1994 Mar 10;368(6467):157–160. doi: 10.1038/368157a0. [DOI] [PubMed] [Google Scholar]
  73. Ullrich O., Stenmark H., Alexandrov K., Huber L. A., Kaibuchi K., Sasaki T., Takai Y., Zerial M. Rab GDP dissociation inhibitor as a general regulator for the membrane association of rab proteins. J Biol Chem. 1993 Aug 25;268(24):18143–18150. [PubMed] [Google Scholar]
  74. Wagner P., Molenaar C. M., Rauh A. J., Brökel R., Schmitt H. D., Gallwitz D. Biochemical properties of the ras-related YPT protein in yeast: a mutational analysis. EMBO J. 1987 Aug;6(8):2373–2379. doi: 10.1002/j.1460-2075.1987.tb02514.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  75. Walter M., Clark S. G., Levinson A. D. The oncogenic activation of human p21ras by a novel mechanism. Science. 1986 Aug 8;233(4764):649–652. doi: 10.1126/science.3487832. [DOI] [PubMed] [Google Scholar]
  76. Walworth N. C., Goud B., Kabcenell A. K., Novick P. J. Mutational analysis of SEC4 suggests a cyclical mechanism for the regulation of vesicular traffic. EMBO J. 1989 Jun;8(6):1685–1693. doi: 10.1002/j.1460-2075.1989.tb03560.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  77. Weijland A., Parmeggiani A. Toward a model for the interaction between elongation factor Tu and the ribosome. Science. 1993 Feb 26;259(5099):1311–1314. doi: 10.1126/science.8446899. [DOI] [PubMed] [Google Scholar]
  78. Wilson B. S., Nuoffer C., Meinkoth J. L., McCaffery M., Feramisco J. R., Balch W. E., Farquhar M. G. A Rab1 mutant affecting guanine nucleotide exchange promotes disassembly of the Golgi apparatus. J Cell Biol. 1994 May;125(3):557–571. doi: 10.1083/jcb.125.3.557. [DOI] [PMC free article] [PubMed] [Google Scholar]
  79. Wuestehube L. J., Schekman R. W. Reconstitution of transport from endoplasmic reticulum to Golgi complex using endoplasmic reticulum-enriched membrane fraction from yeast. Methods Enzymol. 1992;219:124–136. doi: 10.1016/0076-6879(92)19015-x. [DOI] [PubMed] [Google Scholar]
  80. Zerial M., Stenmark H. Rab GTPases in vesicular transport. Curr Opin Cell Biol. 1993 Aug;5(4):613–620. doi: 10.1016/0955-0674(93)90130-i. [DOI] [PubMed] [Google Scholar]
  81. Zhong J. M., Chen-Hwang M. C., Hwang Y. W. Switching nucleotide specificity of Ha-Ras p21 by a single amino acid substitution at aspartate 119. J Biol Chem. 1995 Apr 28;270(17):10002–10007. doi: 10.1074/jbc.270.17.10002. [DOI] [PubMed] [Google Scholar]

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