SLC25A20

This gene product is one of several closely related mitochondrial-membrane carrier proteins that shuttle substrates between cytosol and the intramitochondrial matrix space. This protein mediates the transport of acylcarnitines into mitochondrial matrix for their oxidation by the mitochondrial fatty acid-oxidation pathway. Mutations in this gene are associated with carnitine-acylcarnitine translocase deficiency, which can cause a variety of pathological conditions such as hypoglycemia, cardiac arrest, hepatomegaly, hepatic dysfunction and muscle weakness, and is usually lethal in new born and infants. [provided by RefSeq]

Full Name

solute carrier family 25 (carnitine/acylcarnitine translocase), member 20

Function

Mediates the electroneutral exchange of acylcarnitines (O-acyl-(R)-carnitine or L-acylcarnitine) of different acyl chain lengths (ranging from O-acetyl-(R)-carnitine to long-chain O-acyl-(R)-carnitines) with free carnitine ((R)-carnitine or L-carnitine) across the mitochondrial inner membrane, via a ping-pong mechanism (PubMed:12892634, PubMed:18307102) (Probable). Key player in the mitochondrial oxidation pathway, it translocates the fatty acids in the form of acylcarnitines into the mitochondrial matrix, where the carnitine palmitoyltransferase 2 (CPT-2) activates them to undergo fatty acid beta-oxidation (Probable). Catalyzes the unidirectional transport (uniport) of carnitine at lower rates than the antiport (exchange) (PubMed:18307102).

Biological Process

Biological Process carnitine shuttleTAS:Reactome
Biological Process carnitine transmembrane transportISS:UniProtKB
Biological Process in utero embryonic developmentIEA:Ensembl
Biological Process mitochondrial transportManual Assertion Based On ExperimentIBA:GO_Central

Cellular Location

Mitochondrion inner membrane

Involvement in disease

Carnitine-acylcarnitine translocase deficiency (CACTD):
A rare long-chain fatty acid oxidation disorder. Metabolic consequences include hypoketotic hypoglycemia under fasting conditions, hyperammonemia, elevated creatine kinase and transaminases, dicarboxylic aciduria, very low free carnitine and abnormal acylcarnitine profile with marked elevation of the long-chain acylcarnitines. Clinical features include neurologic abnormalities, cardiomyopathy, arrhythmias, skeletal muscle damage, liver dysfunction and episodes of life-threatening coma, which eventually lead to death. Most patients become symptomatic in the neonatal period with a rapidly progressive deterioration and a high mortality rate.

Topology

Cytoplasmic: 2-12
Helical: 13-31
Mitochondrial matrix: 32-73
Helical: 74-93
Cytoplasmic: 94-112
Helical: 113-131
Mitochondrial matrix: 132-170
Helical: 171-190
Cytoplasmic: 191-211
Helical: 212-230
Mitochondrial matrix: 231-267
Helical: 268-287
Cytoplasmic: 288-301