The PBN1 gene of Saccharomyces cerevisiae: an essential gene that is required for the post-translational processing of the protease B precursor.
The PBN1 gene of Saccharomyces cerevisiae: an essential gene that is required for the post-translational processing of the protease B precursor.
复制标题
酿酒酵母的PBN1基因：蛋白酶B前体翻译后加工所需的必需基因。
DOI：
10.1093/genetics/149.3.1277
复制
发表时间：
1998
期刊：
影响因子：
3.3
通讯作者：
Jones,EW
中科院分区：
文献类型：
--
作者：
Naik,RR;Jones,EW
酿酒酵母液泡水解酶蛋白酶B是一种无活性前体（Prb1p）。前体在经过分泌途径时经历翻译后修饰。除了N链和O链糖基化外，在Prb1p成熟过程中还发生了四种蛋白水解裂解。信号肽酶去除信号肽和大氨基末端前肽的自催化裂解发生在内质网（ER）。在液泡中发生两个羧基末端的裂解：第一次裂解由蛋白酶A催化，第二次裂解由自催化引起。我们已经分离出一个突变体pbn1-1，它在Prb1p的内质网处理中表现出缺陷。Prb1p的前肽不会发生自催化裂解，Prb1p在细胞质中被迅速降解。PBN1与YCL052c在III号染色体上完全相同。PBN1是编码一种新蛋白的重要基因。预测Pbn1p含有亚c端跨膜结构域，但没有信号序列。一个功能性HA表位标记的Pbn1p融合定位于内质网。Pbn1p在其氨基末端区域被n -糖基化，尽管缺乏信号序列，但表明其具有管腔定向。基于这些结果，我们提出Pbn1p的功能之一是帮助Prb1p的自催化处理。
The vacuolar hydrolase protease B in Saccharomyces cerevisiae is synthesized as an inactive precursor (Prb1p). The precursor undergoes post-translational modifications while transiting the secretory pathway. In addition to N- and O -linked glycosylations, four proteolytic cleavages occur during the maturation of Prb1p. Removal of the signal peptide by signal peptidase and the autocatalytic cleavage of the large aminoterminal propeptide occur in the endoplasmic reticulum (ER). Two carboxy-terminal cleavages of the post regions occur in the vacuole: the first cleavage is catalyzed by protease A and the second results from autocatalysis. We have isolated a mutant, pbn1-1, that exhibits a defect in the ER processing of Prb1p. The autocatalytic cleavage of the propeptide from Prb1p does not occur and Prb1p is rapidly degraded in the cytosol. PBN1 was cloned and is identical to YCL052c on chromosome III. PBN1 is an essential gene that encodes a novel protein. Pbn1p is predicted to contain a sub-C-terminal transmembrane domain but no signal sequence. A functional HA epitope-tagged Pbn1p fusion localizes to the ER. Pbn1p is N-glycosylated in its amino-terminal domain, indicating a lumenal orientation despite the lack of a signal sequence. Based on these results, we propose that one of the functions of Pbn1p is to aid in the autocatalytic processing of Prb1p.