Faculty Collaboration Database

Scavenger receptor class B Type I (SR-BI) assembles into detergent-sensitive dimers and tetramers. Biochim Biophys Acta 2007 Jul;1771(7):807-17

Date

04/21/2006

Pubmed ID

16624615

DOI

10.1016/j.bbalip.2006.03.003

Scopus ID

2-s2.0-34250028241 (requires institutional sign-in at Scopus site)   39 Citations

Abstract

High density lipoproteins (HDL) are protective against cardiovascular disease due to their important role in the reverse cholesterol transport (RCT) pathway. The selective transfer of cholesteryl ester (CE) from the HDL core to cells, the last step in RCT, is mediated by scavenger receptor class B type I (SR-BI). SR-BI is a heavily glycosylated cell surface receptor that is highly expressed in the liver, ovaries, testes and adrenal glands, where selective uptake of HDL-CE is most prevalent. Previous studies have shown that SR-BI oligomerizes with itself in steroidogenic tissues as well as in diverse cell lines. In the present study, we provide further evidence for the homo-oligomerization of SR-BI. We show by FPLC and blue native PAGE that SR-BI forms complexes whose sizes suggest the formation of monomers, dimers, and tetramers. Interestingly, homo-oligomerization occurs even with the absence of SR-BI's C-terminal cytoplasmic domain. Finally, we report that an inhibitor of SR-BI-mediated cholesterol transport, BLT-1, and mutations in the putative leucine zipper region of SR-BI have profound effects on SR-BI function, however, they do not affect receptor self-association. These observations indicate that SR-BI homo-oligomerization occurs even when the receptor is non-functional.

Author List

Sahoo D, Darlington YF, Pop D, Williams DL, Connelly MA

Author

Daisy Sahoo PhD Dean, Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
COS Cells
Centrifugation, Density Gradient
Chromatography, Liquid
Cricetinae
Cricetulus
Detergents
Dimerization
Humans
Immunoprecipitation
Mice
Protein Structure, Quaternary
Protein Structure, Tertiary
Scavenger Receptors, Class B