Cholesterol binding, efflux, and a PDZ-interacting domain of scavenger receptor–BI mediate HDL-initiated signaling
J. Clin. Invest. Chatchawin Assanasen, et al. 115:969 doi:10.1172/JCI23858 [Go to this article.]

Figure 9
CD36 extracellular domain is capable of transducing signal if SR-BI transmembrane and cytoplasmic domains are present. (A) COS-M6 cells were transfected with eNOS cDNA and either wild-type SR-BI, CD/SRCT, SR/CDECL/SR, or SR/CDTM/SR cDNA. For detection of eNOS phosphorylation (left), 24 hours after transfection the cells were starved in serum-free DMEM for another 24 hours, the cells were incubated with HDL (50 μg/ml) for 0 or 10 minutes, and cell lysates were analyzed by Western blotting using anti–phospho-eNOS–specific (Ser1179-specific) antibody and anti-eNOS monoclonal antibody. For detection of eNOS activation (right), parallel sets of transfected cells were used, and [³H]L-arginine conversion to [³H]L-citrulline was measured during 15-minute incubations with control buffer or HDL (50 μg/ml). Values (mean ± SEM) are expressed as percent of HDL-stimulated activity above basal activity; n = 4. *P < 0.05 versus wild-type SR-BI. (B and C) HEK 293 cells were transfected with the constructs shown in A and labeled with [³H]photocholesterol; receptors were immunoprecipitated with antibody to the SR-BI C-terminal tail; and the [³H]photocholesterol associated with the receptor was assessed by autoradiography (top). The abundance of immunoprecipitated receptor was assessed by Western blotting (bottom), and the relative amount of [³H]photocholesterol-bound receptor versus total receptor was calculated.