PMID- 10234007
OWN - NLM
STAT- MEDLINE
DCOM- 19990601
LR  - 20191023
IS  - 1529-2401 (Electronic)
IS  - 0270-6474 (Linking)
VI  - 19
IP  - 10
DP  - 1999 May 15
TI  - Altered formation of hemichannels and gap junction channels caused by C-terminal 
      connexin-32 mutations.
PG  - 3752-60
AB  - Hexamers of connexins (Cxs) form hemichannels that dock tightly in series via
      their extracellular domains to give rise to gap junction channels. Here we
      examined the ability of a variety of C-terminal Cx32 mutations, most of which
      have been identified in X-linked Charcot-Marie-Tooth disease, to form
      hemichannels and to complete gap junction channels using the Xenopus oocyte
      system. First, we show that undocked wild-type Cx32 hemichannels at the plasma
      membrane can be detected as opening channels activated by depolarization. We have
      been able to estimate the efficiency of assembly of complete channels by
      measuring the time-dependent incorporation of preformed hemichannels into gap
      junction channels after cell-to-cell contact. These data offer strong evidence
      that hemichannels are the direct precursors of gap junction channels. Of 11 Cx32 
      mutants tested, a group of 5 mutations prevented the formation of functional
      hemichannels at the cell surface, whereas 4 mutations were fully able to form
      precursors but reduced the ability of hemichannels to assemble into complete
      channels, and 2 mutants formed channels normally. The data revealed that a
      minimum length of human Cx32 including the residue Arg-215 is required for the
      expression of hemichannels at the cell surface and that the efficiency of
      hemichannel incorporation into complete channels decreased gradually with the
      progressive shortening of the cytoplasmic C-terminal domain.
FAU - Castro, C
AU  - Castro C
AD  - Unidad de Neurologia Experimental-Consejo Superior de Investigaciones
      Cientificas, Departamento de Investigacion, Hospital "Ramon y Cajal," 28034
      Madrid, Spain.
FAU - Gomez-Hernandez, J M
AU  - Gomez-Hernandez JM
FAU - Silander, K
AU  - Silander K
FAU - Barrio, L C
AU  - Barrio LC
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Neurosci
JT  - The Journal of neuroscience : the official journal of the Society for
      Neuroscience
JID - 8102140
RN  - 0 (Connexins)
RN  - 0 (connexin 32)
SB  - IM
MH  - Animals
MH  - Charcot-Marie-Tooth Disease/genetics/physiopathology
MH  - Connexins/*genetics
MH  - Female
MH  - Gap Junctions/*physiology
MH  - Humans
MH  - *Ion Channel Gating
MH  - Membrane Potentials/physiology
MH  - Mutation
MH  - Patch-Clamp Techniques
MH  - Xenopus
PMC - PMC6782695
EDAT- 1999/05/11 00:00
MHDA- 1999/05/11 00:01
CRDT- 1999/05/11 00:00
PHST- 1999/05/11 00:00 [pubmed]
PHST- 1999/05/11 00:01 [medline]
PHST- 1999/05/11 00:00 [entrez]
PST - ppublish
SO  - J Neurosci. 1999 May 15;19(10):3752-60.