Pyruvate kinase isozyme type M2 (PKM2) interacts and cooperates with Oct-4 in regulating transcription
Pyruvate kinase isozyme type M2 (PKM2) interacts and cooperates with Oct-4 in regulating transcription
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DOI：
10.1016/j.biocel.2007.11.009
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发表时间：
2008-01-01
影响因子：
4
通讯作者：
Kim, Jungho
中科院分区：
文献类型：
--
作者：
Lee, Jungwoon;Kim, Hye Kyoung;Kim, Jungho
Oct-4基因编码一种转录因子，在维持胚胎干细胞的多能性状态中起重要作用，并可能阻止分化过程中激活的基因表达。虽然它在维持胚胎干细胞多能性方面的作用已经得到了很好的证实，但对调节其功能的结合伴侣仍然知之甚少。为了鉴定控制Oct-4功能的蛋白质，我们使用亲和色谱固定Oct-4（POU）与MALDI-TOF（基质辅助激光解吸电离飞行时间）MS（质谱），并分离出一种新的Oct-4相互作用蛋白，丙酮酸激酶型M2（PKM2或M2-PK）。PKM2是丙酮酸激酶的同工酶，其在增殖细胞如胚胎干细胞、胚胎癌细胞以及癌细胞中特异性表达。Oct-4和PKM2从细胞提取物中共亲和沉淀，谷胱甘肽S-转移酶下拉测定显示Oct-4的POU DNA结合结构域是与PKM2相互作用所必需的。此外，PKM2的C-末端结构域（氨基酸307 - 531）参与与Oct-4的结合。此外，PKM2的异位表达增强了Oct-4介导的转录。这些观察结果表明Oct-4转录因子的反式激活潜力受到PKM2的正调控。(C)2007爱思唯尔有限公司保留所有权利。
The Oct-4 gene encodes a transcription factor that plays an important role in maintaining the pluripotent state of embryonic stem cells and may prevent expression of genes activated during differentiation. Although its role in maintaining embryonic stem cell pluripotency is well established, there is still little known about the binding partners that regulate its function. To identify proteins that control Oct-4 function, we used affinity chromatography on immobilized Oct-4 (POU) together with MALDI-TOF (matrix-assisted laser-desorption ionization-time-of-flight) MS (mass spectrometry) and isolated a novel Oct-4-interacting protein, pyruvate kinase type M2 (PKM2 or M2-PK). PKM2 is an isozyme of pyruvate kinase that is specifically expressed in proliferating cells, such as embryonic stem cells, embryonic carcinoma cells, as well as cancer cells. Oct-4 and PKM2 were co-affinity precipitated from cell extracts, and glutathione S-transferase pull-down assays revealed that the POU DNA binding domain of Oct-4 was required for interaction with PKM2. In addition, the C-terminal domain of PKM2 (amino acids 307-531) was involved in binding to Oct-4. Moreover, ectopic expression of the PKM2 enhanced Oct-4-mediated transcription. These observations indicate that the transactivation potential of the Oct-4 transcription factor is positively modulated by PKM2. (C) 2007 Elsevier Ltd. All rights reserved.