Journal: The Journal of Biological Chemistry
Article Title: Activated protein C drives β-arrestin-2- and c-Src-dependent phosphorylation of Cav1 and modulates Cav1 association with PAR1 and GRK5
doi: 10.1016/j.jbc.2026.111190
Figure Lengend Snippet: Model of PAR1–GRK5–βarr2–c-Src regulation by Cav1. A substantial population of PAR1–Cav1 and GRK5–Cav1 complexes coexist at the plasma membrane under basal conditions. APC bound to EPCR cleaves and activates PAR1, resulting in GRK5-dependent phosphorylation of the receptor C-terminal tail within 30 min. This may occur during a time when GRK5 dissociates from Cav1. Next, APC-activated and phosphorylated PAR1 recruits βarr2, which promotes activation of c-Src Y416 phosphorylation and c-Src-dependent Cav1 Y14 phosphorylation, a process that occurs after 30 min and is sustained through 90 min. At 30 min, GRK5–Cav1 may reassociate, whereas activated PAR1 and Y14 phosphorylated Cav1 remain dissociated through the 90 min interval. APC, activated protein C; βarr2, βarr2; Cav1, caveolin-1; EPCR, endothelial protein C receptor; GRK5, GPCR kinase 5; PAR1, protease-activated receptor-1.
Article Snippet: In this study, the following antibodies were used: mouse anti–PAR1 WEDE (Beckman Coulter, #IM2584), anti-Cav1 (CST, #3267S and BD, #610060), anti-Cav1 Y14 phospho antibody (CST, #3251), anti-βarr2 (Abcam, #ab54790), GAPDH (GeneTex, #GT239), c-Src Y416 (CST, #2101), anti-c-Src (CST, #2109), GRK5 (Santa Cruz, #sc-518005), GRK5 polyclonal antibody (Invitrogen, #PA5-96262) anti-GRK4-6 (Millipore, #05-466), anti-HA (CST, #3724S), anti-rabbit IgG (CST, #2729), anti-β-Tubulin (CST, #86298), anti–early endosome antigen-1 (BD Biosciences, #610457), anti-Vinculin (Sigma, #V9131), and anti-HA conjugated to horseradish peroxidase (Roche, #11667475001).
Techniques: Clinical Proteomics, Membrane, Phospho-proteomics, Activation Assay