JAM-A interacts with the integrin α_IIbβ₃. (A) Western blot showing the expression levels of several platelet membrane proteins in resting and stimulated platelet lysates. (B) Representative anti-α_IIb immunoblots of proteins immunoprecipitated with anti–JAM-A from lysates of resting- or thrombin-activated human platelets. (C) Quantitation of normalized optical density of “B” from 3 independent experiments (P = .02). (D) Representative anti-α_IIb immunoblots of proteins immunoprecipitated with anti–JAM-A from lysates of human platelets exposed to immobilized Fg or BSA for 60 minutes. (E) Quantitation of normalized optical density of “D” from 3 independent experiments (P = .01). (F) Representative anti-GPIb immunoblots of proteins immunoprecipitated with anti–JAM-A from lysates of resting- or thrombin-activated human platelets. (G) Representative anti-α_IIb immunoblots of proteins immunoprecipitated with anti–JAM-A from lysates of human platelets activated by ADP or collagen at indicated time points. (H) Super resolution SIM images of human platelets exposed to BSA or Fg and stained for JAM-A (Alexa 568, red); integrin α_IIb (Alexa 647, blue); and filamentous actin (Alexa 488, green). Scale bar: 1 μm. Original magnification ×1000. (I) Anti-α_IIb immunoblots of proteins immunoprecipitated with anti–JAM-A from lysates of human platelets incubated with 2 mg/mL RGDS, or 5 mM EDTA, and treated with or without thrombin, or incubated with 5 mM Mn²⁺ in the presence or absence of Fg. In (B,D,F,G,I), blots were reprobed with anti–JAM-A to ensure equal loading. Shown is a representative blot of at least 3 separate experiments.