Wilms' tumor 1-associating protein regulates G2/M transition through stabilization of cyclin A2 mRNA
Wilms' tumor 1-associating protein regulates G2/M transition through stabilization of cyclin A2 mRNA
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DOI：
10.1073/pnas.0608357103
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发表时间：
2006-11-14
影响因子：
11.1
通讯作者：
Kodama, Tatsuhiko
中科院分区：
文献类型：
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作者：
Horiuchi, Keiko;Umetani, Michihisa;Kodama, Tatsuhiko
肾母细胞瘤1相关蛋白（WTAP）是一种广泛表达的核蛋白。虽然与剪接因子的关系已被假定，但其实际的生理功能仍有待阐明。为了研究WTAP的作用，我们产生了WTAP基因敲除小鼠，并在原代培养细胞中进行了小干扰RNA（siRNA）介导的敲减分析。在使用人脐静脉内皮细胞的DNA微阵列中，WTAP靶向siRNA处理导致细胞周期相关基因的表达显著降低。siRNA介导的WTAP基因敲除可通过cyclin A2 mRNA 3' UTR的一段9个核苷酸的必需序列下调cyclin A2 mRNA的稳定性。WTAP敲低诱导G（2）积累，这部分是由腺病毒过表达细胞周期蛋白A2拯救。此外，WTAP基因敲除小鼠表现出增殖失败，在胚胎第6.5天左右死亡，这一病因与细胞周期蛋白A2基因敲除小鼠几乎相同。总的来说，这些发现确立了WTAP作为稳定细胞周期蛋白A2 mRNA的重要因素，从而调节G（2）/M细胞周期转换。
Wilms' tumor 1-associating protein (WTAP) has been reported to be a ubiquitously expressed nuclear protein. Although a relation to splicing factors has been postulated, its actual physiological function still remains to be elucidated. To investigate the role of WTAP, we generated WTAP-knockout mice and performed small interfering RNA (siRNA)-mediated knockdown analyses in primary cultured cells. In DNA microarrays using human umbilical vein endothelial cells, WTAP-targeted siRNA treatment resulted in markedly reduced expression of cell-cycle-related genes. siRNA-mediated WTAP knockdown down-regulated the stability of cyclin A2 mRNA through a nine-nucleotide essential sequence in cyclin A2 mRNA 3' UTR. WTAP knockdown induced G(2) accumulation, which is partially rescued by adenoviral overexpression of cyclin A2. Moreover, WTAP-null mice exhibited proliferative failure with death resulting at approximately embryonic day 6.5, an etiology almost identical to cyclin A2-null mice. Collectively, these findings establish WTAP as an essential factor for the stabilization of cyclin A2 mRNA, thereby regulating G(2)/M cell-cycle transition.