ABCG1

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 White subfamily. It is involved in macrophage cholesterol and phospholipids transport, and may regulate cellular lipid homeostasis in other cell types. Six alternative splice variants have been identified. [provided by RefSeq, Jul 2008]

ATP Binding Cassette Subfamily G Member 1

Catalyzes the efflux of phospholipids such as sphingomyelin, cholesterol and its oxygenated derivatives like 7beta-hydroxycholesterol and this transport is coupled to hydrlysis of ATP. The lipid efflux is ALB-dependent. Is an active component of the macrophage lipid export complex. Could also be involved in intracellular lipid transport processes. The role in cellular lipid homeostasis may not be limited to macrophages. Prevents cell death by transporting cytotoxic 7beta-hydroxycholesterol.

Amyloid precursor protein catabolic process
Cholesterol efflux
Cholesterol homeostasis
Cholesterol metabolic process
Glycoprotein transport
High-density lipoprotein particle remodeling
Intracellular cholesterol transport
Intracellular receptor signaling pathway
Lipid transport
Low-density lipoprotein particle remodeling
Negative regulation of cholesterol storage
Negative regulation of macrophage derived foam cell differentiation
Phospholipid efflux
Phospholipid homeostasis
Positive regulation of amyloid-beta formation
Positive regulation of cholesterol biosynthetic process
Positive regulation of protein secretion
Regulation of cholesterol esterification
Response to lipid
Response to organic substance
Reverse cholesterol transport

Golgi apparatus membrane; Cell membrane; Endoplasmic reticulum membrane. Predominantly localized in the intracellular compartments mainly associated with the endoplasmic reticulum (ER) and Golgi membranes.

Cytoplasmic: 1-426 aa
Helical: 427-445 aa
Extracellular: 446-456 aa
Helical: 457-477 aa
Cytoplasmic: 478-506 aa
Helical: 507-525 aa
Extracellular: 526-533 aa
Helical: 534-555 aa
Cytoplasmic: 556-567 aa
Helical: 568-586 aa
Extracellular: 587-649 aa
Helical: 650-669 aa
Cytoplasmic: 670-678 aa

Palmitoylation at Cys-315 seems important for trafficking from the endoplasmic reticulum.