Connexin family members target to lipid raft domains and interact with caveolin-1.

摘要: Lipid rafts are cholesterol-sphingolipid-rich microdomains that function as platforms for membrane trafficking and signal transduction. Caveolae specialized lipid raft domains contain the structural proteins known caveolins. Connexins a family of transmembrane self-associate to form cell-cell connections gap junctions linked cytosolic proteins, forming protein complex or Nexus. To determine extent which these intracellular compartments intersect, we have systematically evaluated whether connexins associated with caveolin-1. We show connexin 43 (Cx43) colocalizes, cofractionates, coimmunoprecipitates A mutational analysis Cx43 reveals hypothesized PDZ- presumptive SH2/SH3-binding within carboxyl terminus not required this targeting event its stable interaction Furthermore, appears interact two distinct caveolin-1 domains, i.e., caveolin-scaffolding domain (residues 82-101) C-terminal (135-178). also other (Cx32, Cx36, Cx46) targeted rafts, while Cx26 Cx50 specifically excluded from microdomains. Interestingly, recombinant coexpression recruits where it colocalizes This be unique Cx26, since investigated in study do require rafts. Our results provide first evidence caveolins partition into indicate interactions specific.