The Class B Scavenger Receptors SR-BI and CD36 Are Receptors for Anionic Phospholipids

Abstract

The specific recognition of anionic phospholipids in the outer leaflets of cell membranes and lipoproteins by cell surface receptors may play an important role in a variety of physiologic and pathophysiologic processes (e.g. recognition of damaged or senescent cells by the reticuloendothelial system or lipoprotein homeostasis). Several investigators have described anionic phospholipid binding to cells, and phosphatidylserine (PS) binding to a partially purified approximately 95-kDa membrane protein has recently been reported (Sambrano, G.R., and Steinberg, D. (1995) Proc. Natl. Acad. Sci. U.S.A. 92, 1396-1400). Using both direct binding and ligand competition assays in transfected cells, we have found that two class B scavenger receptors, SR-BI and CD36, can tightly bind PS and phosphatidylinositol (PI)-containing liposomes (Kd for PS liposome binding to SR-BI is approximately 15 micrograms phospholipid/ml or 0.18 nM (mol PS liposomes/l), but not phosphatidylcholine, phosphatidylethanolamine, or sphingomyelin liposomes. PS and PI liposomes, but not the others, could effectively compete with PS liposomes and modified or native lipoproteins for binding to these receptors. Phosphatidic acid, another anionic phospholipid, could also compete, but was not as effective as PS or PI. Class B scavenger receptors are the first molecularly well-defined, specific cell surface receptors for anionic phospholipids to be described.

IL‐13 induces expression of CD36 in human monocytes through PPARγ activation

“…This scavenger receptor also recognizes anionic phospholipids [8], apoptotic cells [9], thrombospondin [29] and P. falciparum-infected erythrocytes [10]. Thus, CD36 is a necessary signaling component of a pattern recognition receptor complex on monocytes/Mu that recognizes modified host proteins.…”

“…The scavenger receptor CD36, an 88-kDa integral membrane protein, is a class B scavenger receptor expressed on a wide variety of cells, in particular on monocytes and monocytederived Mu [5,6]. CD36 is known as a receptor for the uptake of oxidatively modified low-density lipoprotein (LDL) [7] and is also able to bind anionic phospholipid phosphatidylserine [8]. This scavenger receptor is implicated in the clearance of apoptotic cells [9].…”

CD36 Is Important for Chylomicron Formation and Secretion and May Mediate Cholesterol Uptake in the Proximal Intestine

“…The radioactive [9, H(N)] triolein (labels were on the 3 FA molecules, not on the glycerol moiety) and [4][5][6][7][8][9][10][11][12][13][14] C] cholesterol were purchased from New England Nuclear (Boston, MA). Silica gel 60 plates were purchased from Fisher Scientific (Pittsburgh, PA) and were activated before use.…”

Involvement of phosphatidylserine, αvβ3, CD14, CD36, and complement C1q in the phagocytosis of primary necrotic lymphocytes by macrophages

“…Some macrophage receptors, such as CD36, might be able to directly interact with PS on the surface of apoptotic cells (18). In addition, several bridging molecules have been described as binding to PS on apoptotic cells, as follows: the milk fat globule protein MFG-E8 interacting with the vitronectin receptor ␣v␤3 (19,20), the growth arrest-specific gene product GAS-6 representing a ligand for the tyrosine protein kinase receptor MER (6), ␤ 2 -glycoprotein I binding to its receptor (21), and annexin I binding to its receptor (22).…”