apolipoprotein A1 (APOA1)

Function

• role in the reverse transport of cholesterol from tissues to the liver for excretion by promoting cholesterol efflux from tissues & by acting as a cofactor for the lecithin cholesterol acyltransferase (LCAT)
• as part of the SPAP complex, activates spermatozoa motility
• phosphorylation sites are present in plasma
• interacts with APOA1BP & CLU.
• component of a sperm activating protein complex
• interacts with NDRG1

Structure

• palmitoylated
• Met-110 & Met-136 are oxidized to methionine sulfoxides
• belongs to the apolipoprotein A1/A4/E family

Compartment

secreted

Expression

• major protein of plasma HDL
• also found in chylomicrons
• synthesized in the liver & small intestine

Pathology

• oxidized form at Met-110 & Met-136 is increased in individuals with increased risk for coronary artery disease, such as in carrier of the eNOSa/b genotype & exposure to cigarette smoking
  • present in increased levels in aortic lesions relative to native apoA-I & increased levels are seen with increasing severity of disease
• defects in APOA1 are a cause of
  • familial HDL deficiency type 2
  • low HDL levels observed in HDL deficiency type 1
  • amyloidosis type 8
• a mutation in APOA1 is the cause of amyloid polyneuropathy-nephropathy Iowa type (AMYLIOWA)

More general terms

• apolipoprotein A
• phosphoprotein

More specific terms

• apolipoprotein A1 variant (APOA1 variant)
• ETC-216

Additional terms

• apolipoprotein A1/B in serum

Component of

• sperm activating protein complex (SPAP)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=335
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:335
• OMIM: https://mirror.omim.org/entry/105200
• OMIM: https://mirror.omim.org/entry/107680
• OMIM: https://mirror.omim.org/entry/205400
• OMIM: https://mirror.omim.org/entry/604091
• UniProt: http://www.uniprot.org/uniprot/P02647.html