Departamento de Tecnologia Bioquímico-Farmacêutica, Faculdade de Ciências Farmacêuticas, Universidade de São Paulo - USP, São Paulo-SP, Brazil.
BMC Microbiol. 2011 Dec 28;11:268. doi: 10.1186/1471-2180-11-268.
The gene YCL047C, which has been renamed promoter of filamentation gene (POF1), has recently been described as a cell component involved in yeast filamentous growth. The objective of this work is to understand the molecular and biological function of this gene.
Here, we report that the protein encoded by the POF1 gene, Pof1p, is an ATPase that may be part of the Saccharomyces cerevisiae protein quality control pathway. According to the results, Δpof1 cells showed increased sensitivity to hydrogen peroxide, tert-butyl hydroperoxide, heat shock and protein unfolding agents, such as dithiothreitol and tunicamycin. Besides, the overexpression of POF1 suppressed the sensitivity of Δpct1, a strain that lacks a gene that encodes a phosphocholine cytidylyltransferase, to heat shock. In vitro analysis showed, however, that the purified Pof1p enzyme had no cytidylyltransferase activity but does have ATPase activity, with catalytic efficiency comparable to other ATPases involved in endoplasmic reticulum-associated degradation of proteins (ERAD). Supporting these findings, co-immunoprecipitation experiments showed a physical interaction between Pof1p and Ubc7p (an ubiquitin conjugating enzyme) in vivo.
Taken together, the results strongly suggest that the biological function of Pof1p is related to the regulation of protein degradation.
最近，一个被重新命名为丝状生长基因启动子（POF1）的基因 YCL047C 被描述为参与酵母丝状生长的细胞成分。本研究的目的是了解该基因的分子和生物学功能。
在这里，我们报告称，POF1 基因编码的蛋白 Pof1p 是一种 ATP 酶，可能是酿酒酵母蛋白质质量控制途径的一部分。结果表明，Δpof1 细胞对过氧化氢、叔丁基过氧化氢、热休克和蛋白质变性剂（如二硫苏糖醇和衣霉素）的敏感性增加。此外，POF1 的过表达抑制了缺乏编码磷酸胆碱胞苷转移酶的基因的Δpct1 菌株对热休克的敏感性。然而，体外分析表明，纯化的 Pof1p 酶没有胞苷转移酶活性，但具有 ATP 酶活性，催化效率可与其他参与内质网相关蛋白降解（ERAD）的 ATP 酶相媲美。这些发现表明，共免疫沉淀实验表明 Pof1p 与 Ubc7p（一种泛素连接酶）在体内存在物理相互作用。
综上所述，这些结果强烈表明 Pof1p 的生物学功能与蛋白质降解的调节有关。
