Apolipoprotein L (APOL1)

Apolipoprotein L (APOL) proteins belong to the high density lipoprotein family, which plays a central role in cholesterol transport. The cholesterol content of membranes is important in cellular processes such as modulating gene transcription and signal transduction both in the adult brain and during neurodevelopment. The 6 APOL genes are clustered on chromosome 22q12.3.

The cDNA encodes a 383-amino acid polypeptide that includes a 12-amino acid secretory signal peptide. Northern blot analysis detected a 1.3-kb APOL transcript in the pancreas but not in any other human tissues. Affinity immunosorption showed that APOL is not free in the plasma, but is associated with lipoproteins containing APOA1. APOL was found in high density lipoprotein fractions.