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Publication Abstract from PubMed

Scavenger receptor class A (SR-A) proteins are type II transmembrane glycoproteins that form homotrimers on the cell surface. This family has five known members (SCARA1 to 5, or SR-A1 to A5) that recognize a variety of ligands and are involved in multiple biological pathways. Previous reports have shown that some SR-A family members can bind modified low-density lipoproteins (LDL); however, the mechanisms of the interactions between the SR-A members and these lipoproteins are not fully understood. Here we systematically characterize the recognition of SR-A receptors with lipoproteins and report that SCARA1 (SR-A1, CD204), MARCO (SCARA2), and SCARA5 recognize acetylated or oxidized LDL and very low-density lipoproteins (VLDL) in a Ca(2+)-dependent manner through their C-terminal scavenger receptor cysteine-rich (SRCR) domains. These interactions occur specifically between the SRCR domains and the modified apoB component of the lipoproteins, suggesting that they might share a similar mechanism for lipoprotein recognition. Meanwhile, SCARA4, a SR-A member with a carbohydrate recognition domain instead of the SRCR domain at the C-terminus, shows low affinity for modified LDL and VLDL, but binds in a Ca(2+)-independent manner. SCARA3, which does not have a globular domain at the C-terminus, was found to have no detectable binding with these lipoproteins. Taken together, these results provide mechanistic insights into the interactions between SR-A family members and lipoproteins that may help us to understand the roles of SR-A receptors in lipid transport and related diseases such as atherosclerosis.

Recognition of lipoproteins by scavenger receptor class A members.,Cheng C, Zheng E, Yu B, Zhang Z, Wang Y, Liu Y, He Y J Biol Chem. 2021 Jul 9:100948. doi: 10.1016/j.jbc.2021.100948. PMID:34252459^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.