SCP2
Description
The SCP2 (sterol carrier protein 2) is a protein-coding gene located on chromosome 1.
Sterol carrier protein 2 (SCP-2), also known as non-specific lipid-transfer protein or propanoyl-CoA C-acyltransferase, is a protein encoded by the SCP2 gene in humans. This gene produces two proteins: sterol carrier protein X (SCPx) and sterol carrier protein 2 (SCP2). SCPx is a longer protein produced by transcription initiated from the proximal promoter, while SCP2 is a shorter protein produced by transcription initiated from the distal promoter. Both proteins share a common C-terminus. SCPx is a peroxisome-associated thiolase involved in the oxidation of branched-chain fatty acids, while SCP2 is believed to be an intracellular lipid transfer protein. Alternative splicing of this gene generates multiple transcript variants, some of which encode different isoforms. The full-length nature of all transcript variants has not been determined. SCP2 is highly expressed in organs involved in lipid metabolism and may play a role in Zellweger syndrome, where cells lack peroxisomes and have impaired bile acid synthesis. SCP2 interacts with Caveolin 1 and peroxisomal receptor PEX5.
[Isoform SCPx]: A crucial enzyme for the breakdown of branched-chain fatty acids within peroxisomes (PubMed:10706581). It catalyzes the final step of the peroxisomal beta-oxidation process for these fatty acids and also for the side chains of bile acid intermediates, di- and trihydroxycoprostanic acids (DHCA and THCA) (PubMed:10706581). SCPx is also active with medium and long straight chain 3-oxoacyl-CoAs. In vitro, it stimulates the conversion of 7-dehydrocholesterol to cholesterol and facilitates the transfer of phosphatidylcholine and 7-dehydrocholesterol between membranes (By similarity). Both isoforms, SCP2 and SCPx, work together in the peroxisomal oxidation of certain naturally occurring tetramethyl-branched fatty acyl-CoAs (By similarity). {ECO:0000250|UniProtKB:P11915, ECO:0000250|UniProtKB:P32020, ECO:0000269|PubMed:10706581}.
SCP2 is also known as NLTP, NSL-TP, SCOX, SCP-2, SCP-CHI, SCP-X, SCPX.
