State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, People's Republic of China.
Stem Cells. 2012 Apr;30(4):665-72. doi: 10.1002/stem.1034.
OCT4 is a key transcription factor in maintaining the pluripotency and self-renewal of embryonic stem cells (ESCs). Human OCT4 gene can generate three mRNA isoforms (OCT4A, OCT4B, and OCT4B1) by alternative splicing and four protein isoforms (OCT4A, OCT4B-265, OCT4B-190, and OCT4B-164) by alternative splicing or alternative translation initiation. OCT4A is a transcription factor responsible for the stemness of ESCs, while the function of OCT4B protein isoforms is still not clear. We have previously reported that OCT4B-190 functioned in cell stress response. Here, we present another product of OCT4 gene, OCT4B-265, which is upregulated under genotoxic stress in stem cells, and it may function in stress response through p53 signaling pathway. This work gives an insight into the novel function of OCT4B protein isoforms and helps us to understand the complex expression patterns and biological functions of OCT4 gene.
OCT4 是维持胚胎干细胞（ESCs）多能性和自我更新的关键转录因子。人类 OCT4 基因通过选择性剪接可产生三种 mRNA 亚型（OCT4A、OCT4B 和 OCT4B1），通过选择性剪接或选择性翻译起始可产生四种蛋白亚型（OCT4A、OCT4B-265、OCT4B-190 和 OCT4B-164）。OCT4A 是负责 ESCs 干性的转录因子，而 OCT4B 蛋白亚型的功能尚不清楚。我们之前曾报道过 OCT4B-190 在细胞应激反应中发挥作用。在这里，我们介绍 OCT4 基因的另一个产物 OCT4B-265，它在干细胞的遗传毒性应激下上调，可能通过 p53 信号通路在应激反应中发挥作用。这项工作深入了解了 OCT4B 蛋白亚型的新功能，并帮助我们理解 OCT4 基因的复杂表达模式和生物学功能。
