Apolipoprotein C-I (IPR006781)

Short name: ApoC-I

Overlapping homologous superfamilies


Family relationships



Exchangeable apolipoproteins are water-soluble protein components of lipoproteins that solubilise lipids and regulate their metabolism by binding to cell receptors or activating specific enzymes. Apolipoprotein C-I (ApoC-1) is the smallest exchangeable apolipoprotein and transfers among HDL (high density lipoprotein), VLDL (very low-density lipoprotein) and chlylomicrons. ApoC-1 activates lecithin:choline acetyltransferase (LCAT), inhibits cholesteryl ester transfer protein, can inhibit hepatic lipase and phospholipase 2 and can stimulate cell growth. ApoC-1 delays the clearance of beta-VLDL by inhibiting its uptake via the LDL receptor-related pathway [PMID: 11580293]. ApoC-1 has been implicated in hypertriglyceridemia [PMID: 11353333], and Alzheimer s disease [PMID: 11741391].

ApoC-1 is believed to comprise of two dynamic helices that are stabilised by interhelical interactions and are connected by a short linker region. The minimal folding unit in the lipid-free state of this and other exchangeable apolipoproteins comprises the helix-turn-helix motif formed of four 11-mer sequence repeats.

GO terms

Biological Process

GO:0042157 lipoprotein metabolic process

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0005576 extracellular region

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.