Beta-2-glycoprotein 1-dependent macrophage uptake of apoptotic cells. Binding to lipoprotein receptor-related protein receptor family members

Department of Cancer Biology, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA.
Journal of Biological Chemistry (Impact Factor: 4.57). 03/2008; 283(7):3761-6. DOI: 10.1074/jbc.M704990200
Source: PubMed


The recognition and removal of apoptotic cells is critical to development, tissue homeostasis, and the resolution of inflammation.
Many studies have shown that phagocytosis is regulated by signaling mechanisms that involve distinct ligand-receptor interactions
that drive the engulfment of apoptotic cells. Studies from our laboratory have shown that the plasma protein β-2-glycoprotein
1 (β2GP1), a member of the short consensus repeat superfamily, binds phosphatidylserine-containing vesicles and apoptotic
cells and promotes their bridging and subsequent engulfment by phagocytes. The phagocyte receptor for the protein/apoptotic
cell complex, however, is unknown. Here we report that a member of the low density lipoprotein receptor-related protein family
on phagocytes binds and facilitates engulfment of β2GP1-phosphatidylserine and β2GP1-apoptotic cell complexes. Using recombinant
β2GP1, we also show that β2GP1-dependent uptake is mediated by bridging of the target cell to the phagocyte through the protein
C- and N-terminal domains, respectively.

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Available from: Krishnakumar Balasubramanian, Nov 21, 2015
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