Ypt32 recruits the Sec4p guanine nucleotide exchange factor, Sec2p, to secretory vesicles; evidence for a Rab cascade in yeast.
Ypt32 recruits the Sec4p guanine nucleotide exchange factor, Sec2p, to secretory vesicles; evidence for a Rab cascade in yeast.
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DOI：
10.1083/jcb.200201003
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发表时间：
2002-06-10
期刊：
影响因子：
--
通讯作者：
Novick P
中科院分区：
文献类型：
--
作者：
Ortiz D;Medkova M;Walch-Solimena C;Novick P
SEC 2基因是酿酒酵母（Saccharomyces cerevisiae）极性生长所必需的基因。它编码一种759个氨基酸的蛋白质，作为小GTdR Sec 4p的鸟嘌呤核苷酸交换因子，这是高尔基体到质膜转运的调节因子。Sec 2 p激活Sec 4p是囊泡向胞吐部位极化转运所必需的。sec 2和sec 4中的温度敏感（ts）突变导致分泌的紧密阻断和随机分布在细胞中的分泌囊泡的积累。Sec 2 p在分泌囊泡中的适当定位对其功能至关重要，并且在很大程度上独立于Sec 4p。虽然ts突变sec 2 -78不影响核苷酸交换活性，但蛋白质被错误定位。在这里，我们提出的证据表明，Ypt 31/32 p，Rab家族的GTP酶的成员，调节Sec 2 p的功能。首先，YPT 31/YPT 32抑制sec 2 -78突变。第二，Ypt 31/32 p的过表达恢复了Sec 2 - 78 p的定位。第三，Ypt 32 p和Sec 2 p发生生物化学相互作用，但Sec 2 p对Ypt 32 p没有交换活性。我们建议，Ypt 32 p和Sec 4p作为一个信号级联的一部分，其中Ypt 32 p招聘Sec 2 p分泌囊泡;一旦囊泡上，Sec 2 p激活Sec 4p，使囊泡的极化运输到质膜。
SEC2 is an essential gene required for polarized growth of the yeast Saccharomyces cerevisiae. It encodes a protein of 759 amino acids that functions as a guanine nucleotide exchange factor for the small GTPase Sec4p, a regulator of Golgi to plasma membrane transport. Activation of Sec4p by Sec2p is needed for polarized transport of vesicles to exocytic sites. Temperature-sensitive (ts) mutations in sec2 and sec4 result in a tight block in secretion and the accumulation of secretory vesicles randomly distributed in the cell. The proper localization of Sec2p to secretory vesicles is essential for its function and is largely independent of Sec4p. Although the ts mutation sec2-78 does not affect nucleotide exchange activity, the protein is mislocalized. Here we present evidence that Ypt31/32p, members of Rab family of GTPases, regulate Sec2p function. First, YPT31/YPT32 suppress the sec2-78 mutation. Second, overexpression of Ypt31/32p restores localization of Sec2-78p. Third, Ypt32p and Sec2p interact biochemically, but Sec2p has no exchange activity on Ypt32p. We propose that Ypt32p and Sec4p act as part of a signaling cascade in which Ypt32p recruits Sec2p to secretory vesicles; once on the vesicle, Sec2p activates Sec4p, enabling the polarized transport of vesicles to the plasma membrane.
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影响因子：
7.8
作者：
Nair, J;Muller, H;Peterson, M;Novick, P
通讯作者：
Novick, P
DOI：
10.1083/jcb.149.1.95
发表时间：
2000-04-03
期刊：
The Journal of cell biology
影响因子：
--
作者：
Elkind NB;Walch-Solimena C;Novick PJ
通讯作者：
Novick PJ
影响因子：
3.3
作者：
Grote, E;Novick, PJ
通讯作者：
Novick, PJ
影响因子：
3.5
作者：
Ahmadian, MR;Mittal, R;Wittinghofer, A
通讯作者：
Wittinghofer, A
影响因子：
11.4
作者：
Benli, M;Doring, F;Gallwitz, D
通讯作者：
Gallwitz, D