Calmodulin directly interacts with the cx43 carboxyl-terminus and cytoplasmic loop containing three oddd-linked mutants (M147t, r148q, and t154a) that retain α-helical structure, but exhibit loss-of-function and cellular trafficking defects

Li Zheng, Sylvie Chenavas, Fabien Kieken, Andrew Trease, Sarah Brownell, Asokan Anbanandam, Paul L. Sorgen, Gaelle Spagnol

Research output: Contribution to journalArticlepeer-review

1 Scopus citations

Abstract

The autosomal-dominant pleiotropic disorder called oculodentodigital dysplasia (ODDD) is caused by mutations in the gap junction protein Cx43. Of the 73 mutations identified to date, over one-third are localized in the cytoplasmic loop (Cx43CL) domain. Here, we determined the mechanism by which three ODDD mutations (M147T, R148Q, and T154A), all of which localize within the predicted 1-5-10 calmodulin-binding motif of the Cx43CL, manifest the disease. Nuclear magnetic resonance (NMR) and circular dichroism revealed that the three ODDD mutations had little-to-no effect on the ability of the Cx43CL to form α-helical structure as well as bind calmodulin. Combination of microscopy and a dye-transfer assay uncovered these mutations increased the intracellular level of Cx43 and those that trafficked to the plasma membrane did not form functional channels. NMR also identify that CaM can directly interact with the Cx43CT domain. The Cx43CT residues involved in the CaM interaction overlap with tyrosines phosphorylated by Pyk2 and Src. In vitro and in cyto data provide evidence that the importance of the CaM interaction with the Cx43CT may lie in restricting Pyk2 and Src phosphorylation, and their subsequent downstream effects.

Original languageEnglish (US)
Article number1452
Pages (from-to)1-23
Number of pages23
JournalBiomolecules
Volume10
Issue number10
DOIs
StatePublished - Oct 2020

Keywords

  • Calmodulin
  • Circular dichroism
  • Connexin43
  • Cytoplasmic loop domain
  • Gap junctions
  • NMR
  • ODDD

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology

Fingerprint Dive into the research topics of 'Calmodulin directly interacts with the cx43 carboxyl-terminus and cytoplasmic loop containing three oddd-linked mutants (M147t, r148q, and t154a) that retain α-helical structure, but exhibit loss-of-function and cellular trafficking defects'. Together they form a unique fingerprint.

Cite this