May function as regulatory subunit of ATP-sensitive potassium channels (KATP) and form KATP channels with a member of the ATP-sensitive inward rectifier potassium channel family (By similarity). May also have channel activity by itself (in vitro). May protect the heart during hypoxia. May protect against heart failure under conditions of tachycardic stress. Highly expressed in adult heart. Detected at lower levels in head and abdomen. Detected in embryonic myocardial cells and in the developing heart tube. Detected in embryonic dorsal vessels and tracheal system. Drosophila is predominantly active around dawn and dusk, and has large sleep periods during the day and during night. Knockdown of Sur reduces sleep duration during the first half of the night, but has little effect on sleep during the day (PubMed:22105623). Belongs to the ABC transporter superfamily. ABCC family. Conjugate transporter (TC 3.A.1.208) subfamily. Extended N-terminus. On The Other Side - Issue 139 of June 2012