Signaling by the High-Affinity HDL Receptor Scavenger Receptor B Type I

Signaling by the high-affinity HDL receptor scavenger receptor B type I.

Scavenger receptor B type I (SR-BI) plays an important role in mediating cholesterol exchange between cells, high-density lipoprotein (HDL) cholesterol, and other lipoproteins. SR-BI in hepatocytes is essential for reverse cholesterol transport and biliary secretion of HDL cholesterol; thus, it is atheroprotective. More recently, it has been discovered that the HDL-SR-BI tandem serves other fun...

Scavenger receptor class B type I is a multiligand HDL receptor that influences diverse physiologic systems.

Scavenger receptors (SRs) are defined as cell surface membrane proteins that bind chemically modified lipoproteins, such as acetylated LDL (AcLDL) and oxidized LDL (OxLDL), and often many other types of ligands (1–3). Initially, scavenger receptor activity was identified as “AcLDL receptor activity” by Brown, Goldstein, and colleagues (2), who were developing an in vitro model for the depositio...

Remodeling of HDL remnants generated by scavenger receptor class B type I.

Scavenger receptor class B type I (SR-BI) mediates the selective transfer of cholesteryl ester from HDL to cells. We previously established that SR-BI overexpressed in livers of apolipoprotein A-I-deficient mice processes exogenous human HDL2 to incrementally smaller HDL particles. When mixed with normal mouse plasma either in vivo or ex vivo, SR-BI-generated HDL "remnants" rapidly remodel to f...

HDL modification by secretory phospholipase A(2) promotes scavenger receptor class B type I interaction and accelerates HDL catabolism.

During inflammatory states plasma levels of high density lipoprotein (HDL) cholesterol and apolipoprotein A-I (apoA-I) are reduced. Secretory group IIa phospholipase A(2) (sPLA(2)) is a cytokine-induced acute-phase enzyme associated with HDL. Transgenic mice overexpressing sPLA(2) have reduced HDL levels. Studies were performed to define the mechanism for the HDL reduction in these mice. HDL is...

HDL Uptake by Scavenger Receptor SR-BII