SHC-3: a previously unidentified C. elegans Shc family member functions in the insulin-like signaling pathway to enhance survival during L1 arrest

Shc proteins function in many different signaling pathways where they mediate phosphorylation-dependent protein-protein interactions. These proteins are characterized by the presence of two phosphotyrosine-binding domains, an N-terminal PTB and a C-terminal SH2. We describe a previously unrecognized C. elegans Shc gene, shc-3 and characterize its role of in stress response. Both shc-3 and shc-1 are required for long-term survival in L1 arrest, however, they do not act redundantly but rather play distinct roles in this process. SHC-3 function in survival during L1 arrest is DAF-16-dependent, demonstrating that like SHC-1, SHC-3 functions in the Insulin-like signaling pathway. In the absence of SHC-3, nuclear entry and exit are slowed suggesting that SHC-3 is required for rapid changes in DAF-16 signaling.