Xiaochen Wang, Jin Wang, Keiko Gengyo-Ando, Lichuan Gu, Chun-Ling Sun, Chonglin Yang, Yong Shi, Tetsuo Kobayashi, Yigong Shi, Shohei Mitani, Xiao-Song Xie, Ding Xue
Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, CO 80309, USA.
Nature cell biology 2007 MayExternalization of phosphatidylserine, which is normally restricted to the inner leaflet of plasma membrane, is a hallmark of mammalian apoptosis. It is not known what activates and mediates the phosphatidylserine externalization process in apoptotic cells. Here, we report the development of an annexin V-based phosphatidylserine labelling method and show that a majority of apoptotic germ cells in Caenorhabditis elegans have surface-exposed phosphatidylserine, indicating that phosphatidylserine externalization is a conserved apoptotic event in worms. Importantly, inactivation of the gene encoding either the C. elegans apoptosis-inducing factor (AIF) homologue (WAH-1), a mitochondrial apoptogenic factor, or the C. elegans phospholipid scramblase 1 (SCRM-1), a plasma membrane protein, reduces phosphatidylserine exposure on the surface of apoptotic germ cells and compromises cell-corpse engulfment. WAH-1 associates with SCRM-1 and activates its phospholipid scrambling activity in vitro. Thus WAH-1, after its release from mitochondria during apoptosis, promotes plasma membrane phosphatidylserine externalization through its downstream effector, SCRM-1.
Xiaochen Wang, Jin Wang, Keiko Gengyo-Ando, Lichuan Gu, Chun-Ling Sun, Chonglin Yang, Yong Shi, Tetsuo Kobayashi, Yigong Shi, Shohei Mitani, Xiao-Song Xie, Ding Xue. C. elegans mitochondrial factor WAH-1 promotes phosphatidylserine externalization in apoptotic cells through phospholipid scramblase SCRM-1. Nature cell biology. 2007 May;9(5):541-9
PMID: 17401362
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