Wang Jihong, Yan Zhihui, Shen Shi-Hsiang, Whiteway Malcolm, Jiang Linghuo
Department of Molecular and Cellular Pharmacology, College of Pharmaceuticals and Biotechnology, Tianjin University, Tianjin 300072, China.
Can J Microbiol. 2007 Feb;53(2):237-44. doi: 10.1139/w06-125.
Type 2C protein phosphatases (PP2C) represent a diversified protein phosphatase family and play various roles in cells. We previously identified and characterized a novel PP2C phosphatase encoded by the CaPTC7 gene in the human fungal pathogen Candida albicans. The CaPtc7p has 365 amino acids with a PP2C core domain at the C terminus and an additional 116-residue N-terminal sequence containing a mitochondrion-targeting sequence. Here, we show that CaPtc7p is indeed localized in the mitochondrion, the only eukaryotic PP2C phosphatase that has been directly shown to reside in the mitochondrion, suggesting its potential role in the regulation of mitochondrial physiology. Furthermore, we show that the expression of CaPTC7 at both transcriptional and protein levels is developmentally regulated during the serum-induced morphogenesis of C. albicans cells. However, disruption of the two alleles of CaPTC7 does not affect cell viability or filamentous development in C. albicans.
2C型蛋白磷酸酶(PP2C)代表一个多样化的蛋白磷酸酶家族,在细胞中发挥多种作用。我们之前在人类真菌病原体白色念珠菌中鉴定并表征了一种由CaPTC7基因编码的新型PP2C磷酸酶。CaPtc7p有365个氨基酸,在C末端有一个PP2C核心结构域,以及一个包含线粒体靶向序列的额外116个残基的N末端序列。在这里,我们表明CaPtc7p确实定位于线粒体中,这是唯一一种已被直接证明存在于线粒体中的真核PP2C磷酸酶,提示其在调节线粒体生理功能方面的潜在作用。此外,我们表明在白色念珠菌细胞的血清诱导形态发生过程中,CaPTC7在转录和蛋白质水平的表达均受到发育调控。然而,CaPTC7两个等位基因的破坏并不影响白色念珠菌的细胞活力或丝状发育。