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Phosphorylation in the C-terminus of the rat connexin46 (rCx46) and regulation of the conducting activity of the formed connexons

  • Wilhelm J. Walter
  • Carsten Zeilinger
  • Willem Bintig
  • Hans-Albert Kolb
  • Anaclet NgezahayoEmail author
Article

Abstract

To analyse the role of PKC-dependent phosphorylation in the C-terminus of rCx46 in regulation of rCx46 connexons, truncated mutants rCx4645.3 and rCx4644.2 which end before and after PKC-dependent phosphorylation sites respectively were generated. Both rCx4645.3 and rCx4644.2 formed connexons in Xenopus oocytes similar to Cx46wt-connexons. They were activated by depolarisation above −40 mV and at voltages above 50 mV, inactivation was spontaneously observed or induced by PKC activator TPA, suggesting that inactivation does not require PKC-dependent phosphorylation in the C-terminus. Three casein-kinase-II-(CKII)-dependent phosphorylation sites were also identified. rCx4637.7 and rCx4628.2 respectively without two or all of these sites were generated. rCx4637.7-connexons were similar to rCx46wt-connexons. rCx4628.2-connexons comparable to rCx46wt-connexons were observed after injection of 50 times more rCx4628.2-mRNA (25 ng per oocyte). CKII-blocker inhibited depolarisation-evoked currents in oocytes injected with 0.5 ng per oocyte rCx4637.7-mRNA or rCx46wt-mRNA. Injection of 25 ng per oocyte rCx4637.7-mRNA or rCx46wt-mRNA overcame the effect of CKII-inhibitor. We propose that CKII-dependent phosphorylation in the C-terminus accelerates formation of rCx46-connexons.

Keywords

Connexin46 Gap junction Connexon PKC Casein kinase TPA Inactivation 

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Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Wilhelm J. Walter
    • 2
  • Carsten Zeilinger
    • 1
  • Willem Bintig
    • 1
  • Hans-Albert Kolb
    • 1
  • Anaclet Ngezahayo
    • 1
    Email author
  1. 1.Institute of BiophysicsLeibniz University HannoverHannoverGermany
  2. 2.Molecular and Cell PhysiologyHannover Medical SchoolHannoverGermany

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