Insulin Receptor Substrate 4 (IRS4)

IRS4 encodes the insulin receptor substrate 4, a cytoplasmic protein that contains many potential tyrosine and serine/threonine phosphorylation sites. Tyrosine-phosphorylated IRS4 protein has been shown to associate with cytoplasmic signalling molecules that contain SH2 domains. The IRS4 protein is phosphorylated by the insulin receptor tyrosine kinase upon receptor stimulation..Acts as an interface between multiple growth factor receptors possessing tyrosine kinase activity, such as insulin receptor, IGF1R and FGFR1, and a complex network of intracellular signaling molecules containing SH2 domains. Involved in the IGF1R mitogenic signaling pathway. Promotes the AKT1 signaling pathway and BAD phosphorylation during insulin stimulation without activation of RPS6KB1 or the inhibition of apoptosis.