ABCC9

ATP-binding cassette, sub-family C member 9 (ABCC9) also known as sulfonylurea receptor 2 (SUR2) is an is_associated_with::ATP-binding cassette transporter that in humans is encoded by the ABCC9 is_associated_with::gene.

Function
The protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intra-cellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the MRP subfamily which is involved in is_associated_with::multi-drug resistance. This protein is thought to form is_associated_with::ATP-sensitive potassium channels in cardiac, skeletal, and vascular and non-vascular smooth muscle. Protein structure suggests a role as the drug-binding channel-modulating subunit of the extrapancreatic ATP-sensitive potassium channels. is_associated_with::Alternative splicing of this gene results in several products, two of which result from differential usage of two terminal exons and one of which results from exon deletion.
 * SUR2A &mdash; uses exon 38A
 * SUR2B &mdash; uses exon 38B
 * SUR-delta-14 &mdash; lack exon 14 and uses exon 38A

Clinical significance
The gene has been associated with is_associated_with::dilated cardiomyopathy and is_associated_with::Cantú syndrome.

A variant has also been associated with circa 25 minutes more is_associated_with::sleep per day in humans; lack thereof has been associated with three hours less sleep per day in fruit flies.