PMID- 10191254
OWN - NLM
STAT- MEDLINE
DCOM- 19990623
LR  - 20181113
IS  - 0264-6021 (Print)
IS  - 0264-6021 (Linking)
VI  - 339 ( Pt 2)
DP  - 1999 Apr 15
TI  - Synthesis and assembly of connexins in vitro into homomeric and heteromeric
      functional gap junction hemichannels.
PG  - 247-53
AB  - The biogenesis of connexins and their assembly into functional gap junction
      hemichannels (connexons) was studied with the use of a cell-free
      transcription/translation system. Velocity sedimentation on sucrose gradients
      showed that a small proportion of connexin (Cx) 26 and Cx32 that were
      co-translationally translocated into microsomes were oligomers of Cx26 and Cx32. 
      Chemical cross-linking studies showed that these corresponded to hexameric
      connexons. Reconstitution of connexons synthesized in vitro into liposomes
      induced permeability properties consistent with the view that open gap junction
      hemichannels were produced. By using an immunoprecipitation approach, a
      simultaneous translation of Cx26 and Cx32 incorporated into microsomes resulted
      in homomeric connexons. However, supplementation of the translation system in
      vitro with liver Golgi membranes produced heteromeric connexons constructed of
      Cx32 and Cx26, and also resulted in an increased oligomerization especially of
      Cx32. All of the connexins analysed were inserted co-translationally into canine 
      pancreatic microsomal membranes. In addition, Cx26 and Cx43, but not Cx32, were
      also inserted into microsomal membranes post-translationally. Analysis of various
      connexin constructs in which the cytoplasmic carboxy tails were transposed, the
      cytoplasmic tail of Cx43 was truncated or a reporter protein, aequorin, was
      attached to the C-terminus showed that tail length was not the major determinant 
      of the post-translational membrane insertion of connexins.
FAU - Ahmad, S
AU  - Ahmad S
AD  - Department of Medical Biochemistry, University of Wales College of Medicine,
      Heath Park, Cardiff CF4 4XN, Wales, UK.
FAU - Diez, J A
AU  - Diez JA
FAU - George, C H
AU  - George CH
FAU - Evans, W H
AU  - Evans WH
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Biochem J
JT  - The Biochemical journal
JID - 2984726R
RN  - 0 (Biopolymers)
RN  - 0 (Connexins)
RN  - 0 (Liposomes)
SB  - IM
MH  - Animals
MH  - Biopolymers
MH  - Connexins/*chemical synthesis/genetics/metabolism
MH  - Dogs
MH  - Gap Junctions/*metabolism
MH  - Intracellular Membranes/metabolism
MH  - Liposomes
MH  - Microsomes/metabolism
MH  - Precipitin Tests
MH  - Protein Biosynthesis
MH  - Protein Processing, Post-Translational
MH  - Transcription, Genetic
PMC - PMC1220152
EDAT- 1999/04/07 00:00
MHDA- 1999/04/07 00:01
CRDT- 1999/04/07 00:00
PHST- 1999/04/07 00:00 [pubmed]
PHST- 1999/04/07 00:01 [medline]
PHST- 1999/04/07 00:00 [entrez]
PST - ppublish
SO  - Biochem J. 1999 Apr 15;339 ( Pt 2):247-53.