Two GTPase isoforms, ypt31p and ypt32p, are essential for Golgi function in yeast
Two GTPase isoforms, ypt31p and ypt32p, are essential for Golgi function in yeast
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DOI：
10.1002/j.1460-2075.1996.tb01037.x
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发表时间：
1996-12-02
期刊：
影响因子：
11.4
通讯作者：
Gallwitz, D
中科院分区：
文献类型：
--
作者：
Benli, M;Doring, F;Gallwitz, D
在真核细胞中，Ypt/Rab家族的单体GTP酶在胞吞和胞吐过程中的囊泡转运的特定步骤中起调节作用。（YPT 31和YPT 32），其编码表现出>80%序列同一性的Ypt家族成员，而两种基因之一的破坏是表型中性的，YPT 31和YPT 32两者的破坏导致致死性，野生型Ypt 31 p或ypt 32空白背景中短暂的遍在蛋白-Ypt 31 p的耗尽导致高尔基体样膜的大量积累、转化酶分泌的抑制和液泡蛋白成熟的缺陷，在条件致死性ypt 31 -1突变体中观察到类似的变化，在30分钟后，转变到非允许的温度。根据亚细胞分馏，Ypt 31 p的一个显着的部分似乎位于高尔基体富集的膜组分。根据这一点，间接免疫荧光使用亲和纯化的抗Ypt 31 p抗体得到了类似于高尔基体定位的蛋白质观察到的点状染色，从ypt 31和ypt 32突变体中观察到的表型改变，这似乎可能是两个GTP酶参与内高尔基体运输或在最远端的高尔基体隔室的运输囊泡的形成。
In eukaryotic cells, monomeric GTPases of the Ypt/Rab family function as regulators at defined steps of vesicular transport in exo- and endocytosis, Here we report on the isolation and characterization of two genes (YPT31 and YPT32) of the yeast Saccharomyces cerevisiae which encode members of the Ypt family exhibiting >80% sequence identity, Whereas the disruption of one of the two genes was phenotypically neutral, the disruption of both YPT31 and YPT32 led to lethality, Depletion of wild-type Ypt31p or of a short-lived ubiquitin-Ypt31p in a ypt32 null background led to a massive accumulation of Golgi-like membranes, an inhibition of invertase secretion and defects in vacuolar protein maturation, Similar alterations were observed in a conditional-lethal ypt31-1 mutant at 30 min after shift to the non-permissive temperature. According to subcellular fractionation, a significant part of Ypt31p appeared to be located in Golgi-enriched membrane fractions. In accordance with this, indirect immunofluorescence using affinity-purified anti-Ypt31p antibodies gave a punctate staining similar to that observed with Golgi-located proteins, From the phenotypic alterations observed in ypt31 and ypt32 mutants, it seems likely that the two GTPases are involved in intra-Golgi transport or in the formation of transport vesicles at the most distal Golgi compartment.