Positive and negative regulation of a SNARE protein by control of intracellular localization
Positive and negative regulation of a SNARE protein by control of intracellular localization
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DOI：
10.1091/mbc.e03-11-0798
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发表时间：
2004-04-01
影响因子：
3.3
通讯作者：
Neiman, AM
中科院分区：
文献类型：
--
作者：
Nakanishi, H;de los Santos, P;Neiman, AM
在酿酒酵母中，发育调节的可溶性N-乙基马来酰亚胺敏感因子附着蛋白受体（SNARE）蛋白Spo 20 p介导囊泡与原孢子膜的融合，这是孢子形成所需的。Spo 20 p受到其氨基末端结构域中不同序列的正向和负向调节。我们报告说，积极的活动是由一个短的，两亲性的螺旋，足以赋予质膜或原孢子膜定位到绿色荧光蛋白。在体外，这种螺旋与酸性磷脂结合，而在体外减少或消除磷脂结合的突变会在体内破坏Spo 20 p。磷脂池的遗传操作表明，该结构域的可能体内配体是磷脂酸。抑制活性是核靶向信号，其赋予营养细胞和进入减数分裂的细胞中的核定位。然而，当细胞启动孢子形成时，含有抑制结构域的融合体离开细胞核并定位于新生的原孢子膜。因此，SNARE Spo 20 p通过控制其细胞内定位而受到正调控和负调控。
In Saccharomyces cerevisiae, the developmentally regulated Soluble N-ethylmaleimide sensitive factor attachment protein receptor (SNARE) protein Spo20p mediates the fusion of vesicles with the prospore membrane, which is required for the formation of spores. Spo20p is subject to both positive and negative regulation by separate sequences in its amino-terminal domain. We report that the positive activity is conferred by a short, amphipathic helix that is sufficient to confer plasma membrane or prospore membrane localization to green fluorescent protein. In vitro, this helix binds to acidic phospholipids, and mutations that reduce or eliminate phospholipid binding in vitro inactivate Spo20p in vivo. Genetic manipulation of phospholipid pools indicates that the likely in vivo ligand of this domain is phosphatidic acid. The inhibitory activity is a nuclear targeting signal, which confers nuclear localization in vegetative cells and in cells entering meiosis. However, as cells initiate spore formation, fusions containing the inhibitory domain exit the nucleus and localize to the nascent prospore membrane. Thus, the SNARE Spo20p is both positively and negatively regulated by control of its intracellular localization.