The low-density lipoprotein receptor gene family: multiple roles in lipid metabolism

The low-density lipoprotein receptor gene family encompasses a class of end ocytic receptors that exhibit structural similarities to the low-density li poprotein receptor. Members of this gene family are present in both vertebr ate and nonvertebrate species. The identification of naturally occurring mu tations and the application of gene targeting to inactivate receptor genes enabled us to develop animal models to investigate the consequences of indi vidual receptor defects in vivo. Analysis of these animal models revealed e xciting new functions of lipoprotein receptors not only in systemic clearan ce of lipoproteins but also in other important biological processes includi ng reproduction, brain development, and adipositas.