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

Anne Lane Schubert, William Schubert, David C. Spray, Michael P. Lisanti

Research output: Contribution to journalArticle

209 Citations (Scopus)

Abstract

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

Original languageEnglish (US)
Pages (from-to)5754-5764
Number of pages11
JournalBiochemistry
Volume41
Issue number18
DOIs
StatePublished - May 7 2002

Fingerprint

Caveolin 1
Connexins
Connexin 43
Lipids
Caveolins
Membrane Microdomains
Proteins
Membranes
Caveolae
Signal transduction
Sphingolipids
src Homology Domains
Gap Junctions
Signal Transduction
Cholesterol

ASJC Scopus subject areas

  • Biochemistry

Cite this

Connexin family members target to lipid raft domains and interact with caveolin-1. / Schubert, Anne Lane; Schubert, William; Spray, David C.; Lisanti, Michael P.

In: Biochemistry, Vol. 41, No. 18, 07.05.2002, p. 5754-5764.

Research output: Contribution to journalArticle

Schubert, Anne Lane ; Schubert, William ; Spray, David C. ; Lisanti, Michael P. / Connexin family members target to lipid raft domains and interact with caveolin-1. In: Biochemistry. 2002 ; Vol. 41, No. 18. pp. 5754-5764.
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