ABCB1

The membrane-associated 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 MDR/TAP subfamily. Members of the MDR/TAP subfamily are involved in multidrug resistance. The protein encoded by this gene is an ATP-dependent drug efflux pump for xenobiotic compounds with broad substrate specificity. It is responsible for decreased drug accumulation in multidrug-resistant cells and often mediates the development of resistance to anticancer drugs. This protein also functions as a transporter in the blood-brain barrier. Mutations in this gene are associated with colchicine resistance and Inflammatory bowel disease 13. Alternative splicing and the use of alternative promoters results in multiple transcript variants. [provided by RefSeq, Feb 2017]

ATP Binding Cassette Subfamily B Member 1

Translocates drugs and phospholipids across the membrane. Catalyzes the flop of phospholipids from the cytoplasmic to the exoplasmic leaflet of the apical membrane. Participates mainly to the flop of phosphatidylcholine, phosphatidylethanolamine, beta-D-glucosylceramides and sphingomyelins. Energy-dependent efflux pump responsible for decreased drug accumulation in multidrug-resistant cells.

Carboxylic acid transmembrane transport
Ceramide translocation
Export across plasma membrane
G2/M transition of mitotic cell cycle
Phospholipid translocation
Positive regulation of anion channel activity
Regulation of chloride transport
Regulation of response to osmotic stress
Response to drug
Stem cell proliferation
Terpenoid transport
Transepithelial transport
Transmembrane transport
Transport across blood-brain barrier
Xenobiotic transport across blood-brain barrier

Cell membrane; Apical cell membrane

A chronic, relapsing inflammation of the gastrointestinal tract with a complex etiology. It is subdivided into Crohn disease and ulcerative colitis phenotypes. Crohn disease may affect any part of the gastrointestinal tract from the mouth to the anus, but most frequently it involves the terminal ileum and colon. Bowel inflammation is transmural and discontinuous; it may contain granulomas or be associated with intestinal or perianal fistulas. In contrast, in ulcerative colitis, the inflammation is continuous and limited to rectal and colonic mucosal layers; fistulas and granulomas are not observed. Both diseases include extraintestinal inflammation of the skin, eyes, or joints.

Cytoplasmic: 1-44 aa
Helical: 45-67 aa
Extracellular: 68-116 aa
Helical: 117-137 aa
Cytoplasmic: 138-186 aa
Helical: 187-208 aa
Extracellular: 209-215 aa
Helical: 216-236 aa
Cytoplasmic: 237-292 aa
Helical: 293-316 aa
Extracellular: 317-330 aa
Helical: 331-352 aa
Cytoplasmic: 353-771 aa
Helical: 772-732 aa
Extracellular: 733-756 aa
Helical: 757-777 aa
Cytoplasmic: 778-832 aa
Helical: 833-853 aa
Extracellular: 854 aa
Helical: 855-874 aa
Cytoplasmic: 875-934 aa
Helical: 935-957 aa
Extracellular: 958-973 aa
Helical: 974-995 aa
Cytoplasmic: 996-1280 aa