TRAPP stimulates guanine nucleotide exchange on Ypt1p

被引:160
作者
Wang, W [1 ]
Sacher, M [1 ]
Ferro-Novick, S [1 ]
机构
[1] Yale Univ, Sch Med, Howard Hughes Med Inst, Boyer Ctr Mol Med,Dept Cell Biol, New Haven, CT 06519 USA
关键词
exchange factor; small GTPase; secretion; ER-to-Golgi; tethering factor;
D O I
10.1083/jcb.151.2.289
中图分类号
Q2 [细胞生物学];
学科分类号
071009 ; 090102 ;
摘要
TRAPP, a novel complex that resides on early Golgi, mediates the targeting of ER-to-Golgi vesicles to the Golgi apparatus. Previous studies have shown that YPT1, which encodes the small OTP-binding protein that regulates membrane traffic at this stage of the secretory pathway, interacts genetically with BET3 and BET5. Bet3p and Bet5p are 2 of the 10 identified subunits of TRAPP. Here we show that TRAPP preferentially binds to the nucleotide-free form of Ypt1p. Mutants with defects in several TRAPP subunits are temperature-sensitive in their ability to displace GDP from Ypt1p. Furthermore, the purified TRAPP complex accelerates nucleotide exchange on Ypt1p. Our findings imply that Ypt1p, which is present on ER-to-Golgi transport vesicles, is activated at the Golgi once it interacts with TRAPP.
引用
收藏
页码:289 / 295
页数:7
相关论文
共 31 条
[1]   THE GTP-BINDING PROTEIN YPT1 IS REQUIRED FOR TRANSPORT INVITRO - THE GOLGI-APPARATUS IS DEFECTIVE IN YPT1 MUTANTS [J].
BACON, RA ;
SALMINEN, A ;
RUOHOLA, H ;
NOVICK, P ;
FERRONOVICK, S .
JOURNAL OF CELL BIOLOGY, 1989, 109 (03) :1015-1022
[2]   Coupled ER to Golgi transport reconstituted with purified cytosolic proteins [J].
Barlowe, C .
JOURNAL OF CELL BIOLOGY, 1997, 139 (05) :1097-1108
[3]   TRAPP stably associates with the Golgi and is required for vesicle docking [J].
Barrowman, J ;
Sacher, M ;
Ferro-Novick, S .
EMBO JOURNAL, 2000, 19 (05) :862-869
[4]   Two GTPase isoforms, ypt31p and ypt32p, are essential for Golgi function in yeast [J].
Benli, M ;
Doring, F ;
Robinson, DG ;
Yang, XP ;
Gallwitz, D .
EMBO JOURNAL, 1996, 15 (23) :6460-6475
[5]   Asymmetric requirements for a Rab GTPase and SNARE proteins in fusion of COPII vesicles with acceptor membranes [J].
Cao, XC ;
Barlowe, C .
JOURNAL OF CELL BIOLOGY, 2000, 149 (01) :55-65
[6]   IDENTIFICATION AND STRUCTURE OF 4 YEAST GENES (SLY) THAT ARE ABLE TO SUPPRESS THE FUNCTIONAL LOSS OF YPT1, A MEMBER OF THE RAS SUPERFAMILY [J].
DASCHER, C ;
OSSIG, R ;
GALLWITZ, D ;
SCHMITT, HD .
MOLECULAR AND CELLULAR BIOLOGY, 1991, 11 (02) :872-885
[7]   Identification of a Sec4p GTPase-activating protein (GAP) as a novel member of a Rab GAP family [J].
Du, LL ;
Collins, RN ;
Novick, PJ .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1998, 273 (06) :3253-3256
[8]   Vps9p is a guanine nucleotide exchange factor involved in vesicle-mediated vacuolar protein transport [J].
Hama, H ;
Tall, GG ;
Horazdovsky, BF .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1999, 274 (21) :15284-15291
[9]   VPS21 ENCODES A RAB5-LIKE GTP-BINDING PROTEIN THAT IS REQUIRED FOR THE SORTING OF YEAST VACUOLAR PROTEINS [J].
HORAZDOVSKY, BF ;
BUSCH, GR ;
EMR, SD .
EMBO JOURNAL, 1994, 13 (06) :1297-1309
[10]   A novel Rab5 GDP/GTP exchange factor complexed to Rabaptin-5 links nucleotide exchange to effector recruitment and function [J].
Horiuchi, H ;
Lippe, R ;
McBride, HM ;
Rubino, M ;
Woodman, P ;
Stenmark, H ;
Rybin, V ;
Wilm, M ;
Ashman, K ;
Mann, M ;
Zerial, M .
CELL, 1997, 90 (06) :1149-1159