Apolipoprotein A-II: a protein in search of a function

To summarize current findings relevant to the function of apolipoprotein A-II (apoA-II), a major protein component of high density lipoproteins (HDL).

Studies relating to the structure, regulation and genetics of apoA-II are reviewed. These include studies of apoA-II expression in humans and mouse animal models. All studies cited were published between 1972 and 1993.

Since its discovery over 20 years ago, apoA-II has been a protein in search of a function. In fact, it has often been stated that apoA-II has no major function in plasma lipoprotein metabolism. While it is clear that apoA-II does not serve an essential function in HDL metabolism, the evidence overwhelmingly indicates that apoA-II importantly influences HDL functional states and suggests strongly that apoA-II is likely to contribute to atherogenesis.