Apolipoprotein D

Apolipoprotein D is a is_associated_with::protein that in humans is encoded by the APOD is_associated_with::gene. Unlike other is_associated_with::lipoproteins, which are mainly produced in the liver, apolipoprotein D is mainly produced in the brain and testes.

Function
is_associated_with::Apolipoprotein D (Apo-D) is a component of is_associated_with::high-density lipoprotein that has no marked similarity to other apolipoprotein sequences. It has a high degree of homology to plasma is_associated_with::retinol-binding protein and other members of the alpha 2 microglobulin protein superfamily of carrier proteins, also known as lipocalins. It is a glycoprotein of estimated molecular weight 33 KDa. Apo-D is closely associated with the enzyme lecithin:cholesterol acyltransferase - an enzyme involved in lipoprotein metabolism. ApoD has also been shown to be an important link in the transient interaction between HDL and LDL particles and between HDL particles and cells.

Clinical significance
APOD is a biomarker of androgen insensitivity syndrome (AIS). APOD is an androgen up-regulated gene in normal scrotal fibroblast cells in comparison to CAIS labia majora cells.

APOD is associated with neurological disorders and nerve injury, especially related to is_associated_with::myelin sheath. APOD was shown to be elevated in a rat model of is_associated_with::stroke. APOD is elevated in patients with is_associated_with::schizophrenia, is_associated_with::bipolar disorder, and is_associated_with::Alzheimer's disease.