SR-BI Overexpression Lysate

HEK293T cells in 10-cm dishes were transiently transfected with a non-lipid polymer transfection reagent specially designed and manufactured for large volume DNA transfection. Transfected cells were cultured for 48hrs before collection. The cells were lysed in modified RIPA buffer (25mM Tris-HCl pH7.6, 150mM NaCl, 1% NP-40, 1mM EDTA, 1xProteinase inhibitor cocktail mix, 1mM PMSF and 1mM Na3VO4, and then centrifuged to clarify the lysate. Protein concentration was measured by BCA protein assay kit.

SR-BI (scavenger receptor class B member 1, SCARB1) belongs to the CD36 family and acts as a cell surface lipoprotein receptor for a variety of ligands including high density lipoprotein (HDL), phospholipids, phosphatidylserine, and lipoproteins such as lipopolysaccharide (LPS). SR-BI mediates selective uptake of HDL cholesteryl (HDL-C) ester in the liver, steroidogenic tissues, and adipose tissue and facilitates the flux of free and esterified cholesterol between the cell surface and apoB-containing lipoproteins and modified lipoproteins. SR-BI plays a role in antigen capture and cross-presentation from bacteria, parasites, and viruses such as Hepatitis C. In endothelial cells and macrophages, SR-BI is involved in anti-inflammatory and pro-survival signaling, providing protection against atherosclerosis and clearing apoptotic cells (efferocytosis) (1, 2).

At least 5 different human splice variants have been identified with theoretical molecular weights ranging from 60.9 kDa for the canonical sequence to 45 kDa for an N-terminally truncated variant (SR-BII) (3). The extracellular domain of human SR-BI (CLA-1) shares 80%, 80%, 89%, 86% and 84% aa sequence identity with mouse, rat, porcine, rabbit, and bovine SR-BI, respectively. SR-BI is highly glycosylated and removal of N-linked glycosylation reduces lipid transport.

References

1. Linton MF, Tao H, Linton EF, Yancey PG. (2017) SR-BI: A Multifunctional Receptor in Cholesterol Homeostasis and Atherosclerosis. Trends Endocrinol Metab. 28(6):461-472. PMID: 28259375

2. Hoekstra M, Sorci-Thomas M. (2017) Rediscovering scavenger receptor type BI: surprising new roles for the HDL receptor. Curr Opin Lipidol. 28(3):255-260. PMID: 28301373

3. Shen WJ, Asthana S, Kraemer FB, Azhar S. (2018) Scavenger receptor B type 1: expression, molecular regulation, and cholesterol transport function.

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Lysates are guaranteed for 6 months from date of receipt.

Array NBL1-15720

• SR-BI Antibodies
• SR-BI ELISA Kits
• SR-BI Lysate
• SR-BI Proteins
• SR-BI Proteins and Enzymes