Evidence for the presence of a free C-Terminal fragment of Cx43 in cultured cells

Rosy Joshi-Mukherjee, Wanda Coombs, Christine Burrer, Isabel Alvarez de Mora, Mario Delmar, Steven M. Taffet

Research output: Contribution to journalArticle

Abstract

Migration of the gap junction protein connexin 43 (Cx43) in SDS-PAGE yields 2 to 4 distinct bands, detectable in the 40-47 kDa range. Here, we show that antibodies against the carboxy-terminal domain of Cx43 recognized an additional 20-kDa product. This protein was detected in some culture cell lysates. The presence of the 20-kDa band was not prevented by the use of protease inhibitors (Complete® and phenylmethylsulfonyl fluoride (PMSF), 1-5 mM). The band was absent from cells treated with Cx43-specific RNAi, and from those derived from Cx43-deficient mice, indicating that this Cx43-immunoreactive protein is a product of the Cx43 gene. Treatment of CHO cells with cyclosporin A caused a reduction in the amount of full-length Cx43 and a concomitant increase in the amount of the 20-kDa band. Overall, our data show that a fraction of the Cx43-immunoreactive protein pool within a given cell may correspond to a C-terminal fragment of the protein.

Original languageEnglish (US)
Pages (from-to)75-84
Number of pages10
JournalCell Communication and Adhesion
Volume14
Issue number2-3
DOIs
StatePublished - Mar 2007
Externally publishedYes

Fingerprint

Connexin 43
Cultured Cells
Cells
Proteins
Phenylmethylsulfonyl Fluoride
Connexins
CHO Cells
RNA Interference
Protease Inhibitors
Cell culture
Cyclosporine
Polyacrylamide Gel Electrophoresis
Cell Culture Techniques
Genes
Antibodies

Keywords

  • Connexin
  • Connexin 43
  • Cx43
  • Cx43 C-terminal fragment
  • Gap junction

ASJC Scopus subject areas

  • Cell Biology
  • Clinical Biochemistry

Cite this

Evidence for the presence of a free C-Terminal fragment of Cx43 in cultured cells. / Joshi-Mukherjee, Rosy; Coombs, Wanda; Burrer, Christine; Alvarez de Mora, Isabel; Delmar, Mario; Taffet, Steven M.

In: Cell Communication and Adhesion, Vol. 14, No. 2-3, 03.2007, p. 75-84.

Research output: Contribution to journalArticle

Joshi-Mukherjee, Rosy ; Coombs, Wanda ; Burrer, Christine ; Alvarez de Mora, Isabel ; Delmar, Mario ; Taffet, Steven M. / Evidence for the presence of a free C-Terminal fragment of Cx43 in cultured cells. In: Cell Communication and Adhesion. 2007 ; Vol. 14, No. 2-3. pp. 75-84.
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