title: SR-BI and cholesterol uptake into steroidogenic cells.
abstract: Scavenger receptor class B, type I (SR-BI) is a receptor for high-density lipoprotein (HDL) that mediates cellular uptake of HDL cholesteryl ester (HDL CE) and is the major route for cholesterol delivery to the steroidogenic pathway. SR-BI is localized in specialized microvillar channels in the plasma membrane that retain HDL and are sites of selective uptake of HDL CE. The formation of microvillar channels in the adrenal gland requires SR-BI and is regulated by adrenocorticotropin hormone. SR-BI-mediated uptake of HDL CE is a two-step process that requires high-affinity binding of HDL followed by transfer of CE to the membrane. CE uptake is followed by hydrolysis to free cholesterol by a neutral CE hydrolase. In this review, we describe new information on the mechanism of transfer of cholesterol from plasma HDL to the steroidogenic pathway in endocrine cells.
authors.affiliation: Department of Pharmacological Sciences, University Medical Center, State University of New York at Stony Brook, Stony Brook, New York 11794-8651, USA.
authors.forename: Margery A
authors.initials: MA
authors.lastname: Connelly
authors.forename: David L
authors.initials: DL
authors.lastname: Williams
mesh_terms: D000311:Adrenal Glands / Q000166:cytology* / Q000378:metabolism*; D000818:Animals; D018955:CD36 Antigens; D002784:Cholesterol / Q000378:metabolism*; D008076:Cholesterol, HDL / Q000378:metabolism; D006801:Humans; D011971:Receptors, Immunologic / Q000502:physiology*; D051116:Receptors, Scavenger; D051122:Scavenger Receptors, Class B; D013256:Steroids / Q000096:biosynthesis*
chemical_list: D018955:CD36 Antigens; D008076:Cholesterol, HDL; D011971:Receptors, Immunologic; D051116:Receptors, Scavenger; C495124:SCARB1 protein, human; D051122:Scavenger Receptors, Class B; D013256:Steroids; D002784:Cholesterol