P-TEFb的功能及其活性调控机制

The function and regulation mechanism of P-TEFb

P-TEFb是调控真核基因转录延伸的核心转录因子之一,为大多数mRNA转录所必需;与艾滋病、心肌肥大和肿瘤均有密切关系;目前有关P-TEFb的生物学功能及其活性调控机制仍在不断的发现之中。在细胞内,P-TEFb以无活性和可被募集两种复合体存在,并且两种复合体之间可互相转化,以严格维持细胞内P-TEFb的总体活性水平。近年的研究已逐渐揭示P-TEFb活性调控的分子模式,以及调控细胞内P-TEFb活化的信号和分子机理。本文综述近年有关P-TEFb的功能和活性调控机制的研究进展。

P-TEFb,a kinase composed of CDK9 and cyclin T1,is the core factor for stimulating protein-encoding gene transcription elongation in eukaryotic cell.In addition to play important roles in HIV/AIDS,cardiac hypertrophy and tumor pathogenesis,more and more cell biological functions of P-TEFb are still in discovery.In human cells,P-TEFb exists in two distinct complexes：one is inactive and unrecruitable complex and the other is active and recruitable one.Through alternative interaction with its negative or positive regulators,the total cellular P-TEFb activity can be dynamically regulated in response to the demands of cell growth or differentiation and extracellular stimulations.In the past years,the regulation model and signaling pathways of P-TEFb activation have been revealed step by step.Here,these pioneering progressions were summarily reviewed.