APOO

This gene is a member of the apolipoprotein family. Members of this protein family are involved in the transport and metabolism of lipids. The encoded protein associates with HDL, LDL and VLDL lipoproteins and is characterized by chondroitin-sulfate glycosylation. This protein may be involved in preventing lipid accumulation in the myocardium in obese and diabetic patients. Alternative splicing results in multiple transcript variants. Pseudogenes of this gene are found on chromosomes 3, 4, 5, 12 and 16.[provided by RefSeq, Sep 2009]

Full Name

Apolipoprotein O

Function

Component of the MICOS complex, a large protein complex of the mitochondrial inner membrane that plays crucial roles in the maintenance of crista junctions, inner membrane architecture, and formation of contact sites to the outer membrane. Plays a crucial role in crista junction formation and mitochondrial function (PubMed:25764979). Can promote cardiac lipotoxicity by enhancing mitochondrial respiration and fatty acid metabolism in cardiac myoblasts (PubMed:24743151). Promotes cholesterol efflux from macrophage cells. Detected in HDL, LDL and VLDL. Secreted by a microsomal triglyceride transfer protein (MTTP)-dependent mechanism, probably as a VLDL-associated protein that is subsequently transferred to HDL (PubMed:16956892).

Biological Process

Cristae formation Source: UniProtKB
Inner mitochondrial membrane organization Source: UniProtKB
Lipid transport Source: UniProtKB-KW

Cellular Location

Endoplasmic reticulum membrane; Secreted; Golgi apparatus membrane; Mitochondrion inner membrane; Mitochondrion. Exists in three distinct forms: a glycosylated and secreted form, an ER/Golgi-resident form and a non-glycosylated mitochondrial form.

Topology

Helical: 108-128 aa

PTM

O-glycosylation; glycosaminoglycan of chondroitin-sulfate type.