PTEN

This gene was identified as a tumor suppressor that is mutated in a large number of cancers at high frequency. The protein encoded by this gene is a phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase. It contains a tensin like domain as well as a catalytic domain similar to that of the dual specificity protein tyrosine phosphatases. Unlike most of the protein tyrosine phosphatases, this protein preferentially dephosphorylates phosphoinositide substrates. It negatively regulates intracellular levels of phosphatidylinositol-3,4,5-trisphosphate in cells and functions as a tumor suppressor by negatively regulating AKT/PKB signaling pathway. The use of a non-canonical (CUG) upstream initiation site produces a longer isoform that initiates translation with a leucine, and is thought to be preferentially associated with the mitochondrial inner membrane. This longer isoform may help regulate energy metabolism in the mitochondria. A pseudogene of this gene is found on chromosome 9. Alternative splicing and the use of multiple translation start codons results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Feb 2015]

该基因被鉴定为一种肿瘤抑制因子，其在大量癌症中以高频率发生突变。该基因编码的蛋白是一种磷脂酰肌醇-3,4,5-三磷酸3-磷酸酶。该蛋白包含一个类似于tensin的结构域以及一个类似于双特异性蛋白酪氨酸磷酸酶的催化结构域。与大多数蛋白酪氨酸磷酸酶不同，此蛋白优先去磷酸化磷脂酰肌醇底物。它负向调控细胞内磷脂酰肌醇-3,4,5-三磷酸的水平，并通过负向调控AKT/PKB信号通路发挥肿瘤抑制功能。使用非典型（CUG）上游启动位点产生的更长型异构体以亮氨酸起始翻译，并被认为优先与线粒体内膜结合。这种更长型异构体可能有助于调节线粒体内的能量代谢。该基因的伪基因位于第9号染色体上。可变剪接和多种翻译起始密码子的使用导致编码不同异构体的多种转录变体。[由RefSeq提供，2015年2月]