This receptor probably binds to the four different molluscan insulin-related peptides and has a tyrosine-protein kinase activity. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Probable tetramer of 2 alpha and 2 beta chains linked by disulfide bonds. The alpha chains contribute to the formation of the ligand-binding domain, while the beta chains carry the kinase domain (By similarity). Belongs to the protein kinase superfamily. Tyr protein kinase family. Insulin receptor subfamily.