cup-4 encodes a non-alpha ligand-gated ion channel with similarity to the nicotinic acetylcholine receptors; cup-4 is required cell autonomously for efficient fluid endocytosis in coelomocytes; cup-4 mutant animals display reduced levels of plasma membrane phosphatidylinositol 4,5-bisphosphate, suggesting that CUP-4 may regulate endocytosis via regulation of phospholipase C activity; in addition, cup-4 mutants display disorganized clathrin and RME-1 at the coelomocyte plasma membrane; CUP-4::GFP is expressed in coelomocytes where it localizes to the cytoplasm, primarily to cytoplasmic vesicles.
Predicted to enable neurotransmitter receptor activity. Involved in several processes, including determination of adult lifespan; positive regulation of egg-laying behavior; and response to caloric restriction. Located in cytoplasmic vesicle membrane.