通过核质转运调节细胞凋亡的蛋白质

Proteins Regulating Cell Apoptosis through Nucleocytoplasmic Transport

凋亡,也称Ⅰ型程序性细胞死亡,是细胞在面临严重威胁时发起的保护性主动死亡机制.凋亡对于个体的生长发育及各种生理功能具有不可或缺的作用.作为涉及整个细胞的复杂过程,凋亡的顺利进行有赖于众多凋亡相关因子的协调合作与精确调控.细胞受到凋亡刺激后,核内的某些蛋白质转运出核,将凋亡信号传递到核外,胞质内的多种蛋白质则转运入核,在细胞核这一信息整合的大本营直接发挥作用.这种双向交流机制在胞核与胞质间建立起密切的联系,同时使得相关蛋白质在特定场所发挥促进或抑制凋亡的作用,确保凋亡信号及时、通畅、有序地传递.因此,蛋白质的核质转运作为介导胞核与胞质物质交换、信号交流的关键机制,在凋亡过程中就显得尤为重要.本文主要就核质转运的机制、通过核质转运调节凋亡的蛋白质及其作用机理作一综述.

Apoptosis, also called type I programmed cell death, is a kind of protective and initiative death mechanism for cells under rigorous threats. Apoptosis plays an indispensable role in growth, development and physiological functions of organisms. As a complicated process the whole cell runs on, various apoptotic proteins in nucleus and cytoplasm must team up mutually by precise regulations to ensure apoptosis. Some of the apoptotic proteins, distributing in both cytoplasm and nucleus, shuttle between the two compartments by virtue of nucleocytoplasmic transport. It has been shown that after apoptotic stimulation, some protein factors find ways into cytoplasm from nucleus, conveying apoptotic signals derived from the latter. Meanwhile, related factors in cytoplasm are transloeated into nucleus, functioning directly in the headquarter of ceils. Based on such bi-directional communications, close links are established between the two separate compartments, and related proteins are able to play their pro-apoptotic or anti-apoptotic roles in specific sites of cells, ensuring prompt, uninterrupted and ordered transferring of apoptotic signals. Therefore, as a critical mechanism mediating substance-exchange and signal-crosstalk between nucleus and cytoplasm, nucleocytoplasmic transport is essential for initiating and progressing apoptosis. In this review, we mainly focused on the current knowledge regarding mechanisms of nucleocytoplasmic transport, apoptotic proteins relying on such mechanisms, as well as their effects on apoptosis.