Glyceraldehyde-3-phosphate dehydrogenase in the extracellular space inhibits cell spreading
Glyceraldehyde-3-phosphate dehydrogenase in the extracellular space inhibits cell spreading
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DOI：
10.1016/j.bbagen.2005.07.013
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发表时间：
2005-11-30
影响因子：
3
通讯作者：
Nakano, Y
中科院分区：
文献类型：
--
作者：
Yamaji, R;Chatani, E;Nakano, Y
研究了胞外3-磷酸甘油醛脱氢酶(GAPDH)的存在及其新功能。在哺乳动物细胞系COS-7、HEK293、MCF-7、HepG2、PC-12和Neuro-2a细胞的条件培养液中，检测到与细胞内相同分子量的胞外GAPDH。Western印迹分析表明，在COS-7细胞的条件培养液中存在GAPDH，而不是α-微管蛋白(一种细胞内标记蛋白)。此外，在大鼠血清中也发现了GAPDH。这些结果表明GAPDH是在细胞外分泌的。在COS-7、HEK293和HepG2细胞的培养液中加入GAPDH可使细胞发生形态变化。在COS-7细胞中，胞外GAPDH在不影响细胞生长的情况下抑制细胞的铺展。Western印迹和免疫荧光显微镜分析表明，胞外GAPDH以时间和剂量依赖的方式与COS-7细胞结合。然而，在GAPDH151位用丝氨酸取代半胱氨酸的突变体不会与细胞结合，不会降低细胞的铺展效率，也不会引起细胞形态的变化。这些结果表明，Cys151参与了GAPDH与细胞的结合和GAPDH抑制细胞扩散的过程。(C)2005 Elsevier B.V.保留所有权利。
The occurrence and the novel function of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) in the extracellular space were studied. The extracellular GAPDH with the same molecular mass as the intracellular GAPDH was detected in the conditioned medium of mammalian cultured cell lines such as COS-7, HEK293, MCF-7, HepG2, PC-12, and neuro-2a cells. Western blot analysis represented the occurrence of GAPDH, but not alpha-tubulin (an intracellular marker protein), in the conditioned medium of COS-7 cells. Furthermore, GAPDH was found in rat serum. These results indicate that GAPDH was secreted outside of the cells. Addition of GAPDH to the cultured medium of COS-7, HEK293 and HepG2 cells allowed cells to undergo morphological changes. In COS-7 cells, the extracellular GAPDH inhibited cell spreading without influencing the cell growth. Western blot and immunofluorescent microscopy analyses revealed that the extracellular GAPDH bound to COS-7 cells in time- and dose-dependent manners. However, a mutant substituting Ser for Cys at position 151 of GAPDH resulted in no binding to the cells, no decreased cell-spreading efficiency and no cell morphological changes. These results indicate that the Cys151 was involved in the binding of GAPDH to cells and the GAPDH-inhibited cell spreading. (c) 2005 Elsevier B.V. All rights reserved.