Shemer Gidi, Podbilewicz Benjamin
Department of Biology, Technion-Israel Institute of Technology, Haifa, 32000, Israel.
Genes Dev. 2002 Dec 15;16(24):3136-41. doi: 10.1101/gad.251202.
General mechanisms by which Hox genes establish cell fates are known. However, a few Hox effectors mediating cell behaviors have been identified. Here we found the first effector of LIN-39/HoxD4/Dfd in Caenorhabditis elegans. In specific vulval precursor cells (VPCs), LIN-39 represses early and late expression of EFF-1, a membrane protein essential for cell fusion. Repression of eff-1 is also achieved by the activity of CEH-20/Exd/Pbx, a known cofactor of Hox proteins. Unfused VPCs in lin-39(-);eff-1(-) double mutants fail to divide but migrate, executing vulval fates. Thus, lin-39 is essential for inhibition of EFF-1-dependent cell fusion and stimulation of cell proliferation during vulva formation. Supplemental material is available at http://www.genesdev.org.
Hox基因建立细胞命运的一般机制已为人所知。然而，介导细胞行为的少数Hox效应因子已被鉴定出来。在这里，我们在秀丽隐杆线虫中发现了LIN-39/HoxD4/Dfd的首个效应因子。在特定的外阴前体细胞（VPCs）中，LIN-39抑制EFF-1的早期和晚期表达，EFF-1是一种对细胞融合至关重要的膜蛋白。CEH-20/Exd/Pbx（一种已知的Hox蛋白辅因子）的活性也能实现对eff-1的抑制。lin-39(-);eff-1(-)双突变体中未融合的VPCs无法分裂但能迁移，执行外阴命运。因此，lin-39对于抑制外阴形成过程中EFF-1依赖的细胞融合和刺激细胞增殖至关重要。补充材料可在http://www.genesdev.org获取。
