PMID- 11058688
OWN - NLM
STAT- MEDLINE
DCOM- 20010125
LR  - 20231213
IS  - 0022-2631 (Print)
IS  - 0022-2631 (Linking)
VI  - 178
IP  - 1
DP  - 2000 Nov 1
TI  - Slow gating of gap junction channels and calmodulin.
PG  - 55-70
AB  - Certain COOH-terminus mutants of connexin32 (Cx32) were previously shown to form 
      channels with unusual transjuctional voltage (V(j)) sensitivity when tested 
      heterotypically in oocytes against Cx32 wild type. Junctional conductance (G(j)) 
      slowly increased by severalfold or decreases to nearly zero with V(j) positive or 
      negative, respectively, at mutant side, and V(j) positive at mutant side reversed 
      CO(2)-induced uncoupling. This suggested that the CO(2)-sensitive gate might be a 
      V(j)-sensitive slow gate. Based on previous data for calmodulin (CaM) involvement 
      in gap junction function, we have hypothesized that the slow gate could be a 
      CaM-like pore plugging molecule (cork gating model). This study describes a 
      similar behavior in heterotypic channels between Cx32 and each of four new Cx32 
      mutants modified in cytoplasmic-loop and/or COOH-terminus residues. The mutants 
      are: ML/NN+3R/N, 3R/N, ML/NN and ML/EE; in these mutants, N or E replace M105 and 
      L106, and N replace R215, R219 and R220. This study also reports that inhibition 
      of CaM expression strongly reduces V(j) and CO(2) sensitivities of two of the 
      most effective mutants, suggesting a CaM role in slow and chemical gating.
FAU - Peracchia, C
AU  - Peracchia C
AD  - Department of Pharmacology and Physiology, University of Rochester, School of 
      Medicine and Dentistry, 601 Elmwood Avenue, Rochester, NY 14642-8711, USA.
FAU - Wang, X G
AU  - Wang XG
FAU - Peracchia, L L
AU  - Peracchia LL
LA  - eng
GR  - GM20113/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, U.S. Gov't, P.H.S.
PL  - United States
TA  - J Membr Biol
JT  - The Journal of membrane biology
JID - 0211301
RN  - 0 (Calmodulin)
RN  - 0 (Connexins)
RN  - 121127-32-0 (connexin 38)
RN  - 142M471B3J (Carbon Dioxide)
SB  - IM
MH  - Animals
MH  - Calmodulin/*biosynthesis/genetics
MH  - Carbon Dioxide/metabolism
MH  - Connexins/genetics
MH  - Electric Conductivity
MH  - Gap Junctions/*physiology
MH  - Gene Expression
MH  - Ion Channel Gating/*physiology
MH  - Oocytes/metabolism/physiology
MH  - Xenopus laevis
MH  - Gap Junction beta-1 Protein
EDAT- 2000/11/04 11:00
MHDA- 2001/02/28 10:01
CRDT- 2000/11/04 11:00
PHST- 2000/11/04 11:00 [pubmed]
PHST- 2001/02/28 10:01 [medline]
PHST- 2000/11/04 11:00 [entrez]
AID - 10.1007/s002320010015 [pii]
AID - 10.1007/s002320010015 [doi]
PST - ppublish
SO  - J Membr Biol. 2000 Nov 1;178(1):55-70. doi: 10.1007/s002320010015.