mutation of the zebrafish nucleoporin elys sensitizes tissue progenitors to replication stress突变的斑马鱼nucleoporin伊利糖分会让组织祖细胞复制的压力.pdfVIP

Mutation of the Zebrafish Nucleoporin elys Sensitizes Tissue Progenitors to Replication Stress 1. 1. 1. 1 1 Gangarao Davuluri , Weilong Gong , Shamila Yusuff , Kristin Lorent , Manimegalai Muthumani , Amy C. Dolan1, Michael Pack1,2* 1 Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America, 2 Department of Cell Developmental Biology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America Abstract The recessive lethal mutation flotte lotte (flo) disrupts development of the zebrafish digestive system and other tissues. We show that flo encodes the ortholog of Mel-28/Elys, a highly conserved gene that has been shown to be required for nuclear integrity in worms and nuclear pore complex (NPC) assembly in amphibian and mammalian cells. Maternal elys expression sustains zebrafish flo mutants to larval stages when cells in proliferative tissues that lack nuclear pores undergo cell cycle arrest and apoptosis. p53 mutation rescues apoptosis in the flo retina and optic tectum, but not in the intestine, where the checkpoint kinase Chk2 is activated. Chk2 inhibition and replication stress induced by DNA synthesis inhibitors were lethal to flo larvae. By contrast, flo mutants were not sensitized to agents that cause DNA double strand breaks, thus showing that loss of Elys disrupts responses to selected replication inhibitors. Elys binds Mcm2-7 complexes derived from Xenopus egg extracts. Mutation of elys reduced chromatin binding of Mcm2, but not binding of Mcm3 or Mcm4 in the flo intestine. These in vivo data indicate a role for Elys in Mcm2-chromatin interactions. Furthermore, the