The role of the COOH terminus of Sec2p in the transport of post-Golgi vesicles.
The role of the COOH terminus of Sec2p in the transport of post-Golgi vesicles.
复制标题
DOI：
10.1083/jcb.149.1.95
复制
发表时间：
2000-04-03
期刊：
影响因子：
--
通讯作者：
Novick PJ
中科院分区：
文献类型：
--
作者：
Elkind NB;Walch-Solimena C;Novick PJ
Sec2p是S.啤酒。Sec2p NH2末端编码Rab蛋白Sec4p的交换因子。Sec2p与囊泡相关，在Sec2p COOH末端突变体中，Sec4p和囊泡不再积累在芽尖。因此，Sec2p COOH末端在靶向囊泡中起作用，然而，功能机制尚不清楚。我们发现截短和全长Sec2蛋白的交换活性相当，这意味着COOH末端不改变交换率。与Sec4p相似，全长Sec2-GFP集中在芽尖。一个COOH末端的58个氨基酸的结构域是必需的，但不足以定位。Sec2p定位依赖于肌动蛋白、Myo2p和Sec1p、Sec6p和Sec9p功能。全长，但不是羧基末端截短的Sec2蛋白富集在膜上。在37 ° C下，全长Sec2p的膜结合在sec6 - 4和sec9 - 4背景中减少，但在25 ° C下不受影响。总之，这些数据与Sec2蛋白的定位损失与膜结合减少相关。此外，Sec2p膜附着基本上是Sec4p独立的，支持Sec2p通过未鉴定的Sec2p受体与膜相互作用的观点，这将增加Sec4p的Sec2p交换活性的可及性。
Sec2p is required for the polarized transport of secretory vesicles in S. cerevisiae. The Sec2p NH2 terminus encodes an exchange factor for the Rab protein Sec4p. Sec2p associates with vesicles and in Sec2p COOH-terminal mutants Sec4p and vesicles no longer accumulate at bud tips. Thus, the Sec2p COOH terminus functions in targeting vesicles, however, the mechanism of function is unknown. We found comparable exchange activity for truncated and full-length Sec2 proteins, implying that the COOH terminus does not alter the exchange rate. Full-length Sec2-GFP, similar to Sec4p, concentrates at bud tips. A COOH-terminal 58–amino acid domain is necessary but not sufficient for localization. Sec2p localization depends on actin, Myo2p and Sec1p, Sec6p, and Sec9p function. Full-length, but not COOH-terminally truncated Sec2 proteins are enriched on membranes. Membrane association of full-length Sec2p is reduced in sec6-4 and sec9-4 backgrounds at 37°C but unaffected at 25°C. Taken together, these data correlate loss of localization of Sec2 proteins with reduced membrane association. In addition, Sec2p membrane attachment is substantially Sec4p independent, supporting the notion that Sec2p interacts with membranes via an unidentified Sec2p receptor, which would increase the accessibility of Sec2p exchange activity for Sec4p.
登录
查看更多内容
影响因子：
7.8
作者：
Nair, J;Muller, H;Peterson, M;Novick, P
通讯作者：
Novick, P
影响因子：
5.9
作者：
GRISCELLI, C;DURANDY, A;PRUNIERAS, M
通讯作者：
PRUNIERAS, M
影响因子：
3.5
作者：
Cormack, BP;Valdivia, RH;Falkow, S
通讯作者：
Falkow, S
影响因子：
3.6
作者：
HURVITZ, H;GILLIS, R;OKON, E
通讯作者：
OKON, E
影响因子：
56.9
作者：
Echard, A;Jollivet, F;Goud, B
通讯作者：
Goud, B