Mutational analysis of Caenorhabditis elegans CED‐4

FEBS Letters

Seshagiri, Somasekar¹  Miller, Lois K²  Chang, Wen-teh² 

[1] Department of Genetics, The University of Georgia, Athens, GA 30602, USA;Department of Entomology, The University of Georgia, Athens, GA 30602, USA

关键词: Apoptosis;    Ced-4;    Death effector domain;    FADD;    FLICE;    Caspase activation;   

DOI  :  10.1016/S0014-5793(98)00493-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Much of our knowledge concerning the genetics that regulate cell death has come from the studies of cell death during the development of the nematode Caenorhabditis elegans. Of the 14 genes identified as components of nematode cell death pathways, two genes, ced-3 and ced-4, are required to promote cell death and a third, ced-9, blocks cell death. Recent studies show CED-4 to be an activator of CED-3 and CED-9 to be an inhibitor of CED-4. Two published sequence alignments suggest that CED-4 contains a death effector domain (DED), a protein sequence motif present in other death signaling proteins like Fadd and Flice; one study suggests a DED sequence similarity near the N-terminus while the other found sequence similarity near the C-terminus of CED-4. Using mutational analysis we have tested the functional significance of the conserved residues found within the putative DEDs of CED-4. Mutations in two conserved residues within the putative N-terminal DED of CED-4 affected its function, while mutations in the conserved residues within the putative C-terminal DED had no effect on CED-4 function. Our results do not support the presence of a DED in the C-terminus of CED-4 and suggest a potential role for the N-terminus in CED-4 function, possibly as a DED or as a CARD (caspase recruitment domain). We also found that CED-9 associated with all the CED-4 mutants and inhibited the activity of all the active-CED-4 mutants.

【 授权许可】

Unknown