Association of CD36 with integrins and tetraspanins. HDMECs were lysed in 1% Brij 99 (supplemental Figures 1-2). One milligram of protein was immunoprecipitated with a combination of 3 μg of FA6-152 and 2 μg of CRF-2712 anti-CD36 Abs (lane 2) or 5 μg of nonimmune mouse Ab (lane 1). The immunoprecipitants were Western blotted with Abs against (A) identified integrin subunits in Ab-array assays in supplemental Figure 1B or in platelets and (B) tetraspanin family members. (C) To address the role of CD9 and CD151 as linkers for the association of integrin β1 with CD36, lungs from CD151- and CD9-null mice were isolated, and proteins were extracted, as described in the immunoprecipitation section in “Methods.” Anti-CD36 Abs (lane 2) or nonimmune IgG (lane 1) immunoprecipitants were probed for anti-integrin β1 Abs. The lack of CD9 or CD151 did not abolish the CD36-β1 interaction suggesting that either these 2 tetraspanins can compensate for each other,²⁴  or there is a direct interaction between CD36 and β1, as proposed by others.^8,18