3.A.1.204.12
The intracellular sterol transporter, ABCG1 (Tarling and Edwards, 2011). Involved in cell signalling, creation of membrane asymmetry and apoptosis (Quazi and Molday, 2011). Promotes cholesterol efflux from macrophages and other cells to the mature forms of HDL (HDL2 and HDL3) (Voloshyna and Reiss, 2011).  Plays a role in arteriosclerosis (Münch et al. 2012).  The diverse functions in various cell types have been reviewed by Tarling (2013).  Many mammals have two isoforms, long and short, but mice have only the short isoform (Burns et al. 2013).  Residues have been identified that play roles in stability, oligomerization and trafficking (Wang et al. 2013).  Both the full-length and the short isoforms of ABCG1 can dimerize with ABCG4 (3.A.1.204.20) (Hegyi and Homolya 2016). Cholesterol-binding motifs in the membrane may allow transport of different cholesterol pools (Dergunov et al. 2018). It is required for maintenance of cellular cholesterol levels (Sun et al. 2021). It plays a role in the occurrance of some lipids and protein in HDL such as 7-ketocholesterol and some essential proteins such as alpha-1-antitrypsin, apoA-4, apoB-100, and serum amyloid A (SAA) (Wu et al. 2022). ABCG1-mediated cholesterol efflux influences coronary atherosclerosis and cardiovascular risk in Rheumatoid Arthritis (Karpouzas et al. 2023). Aberrant cholesterol homeostasis is a hallmark of cancer and is implicated in metastasis as well as chemotherapeutic resistance. Liver X receptors (LXRs) are the key transcription factors that induce cholesterol efflux via enhancing the expression of ABCA1 and ABCG1 (Taank et al. 2024). Ergosterol and its metabolites are agonists of Liver X receptor and their anticancer potential in colorectal cancer.  Cholesterol accumulation promotes cellular senescence in photoreceptor rod cells (Terao et al. 2024).