Abstract
The ability of certain connexins to form open hemichannels has been exploited to study the pore structure of gap junction (hemi)channels. Cysteine scanning mutagenesis was applied to cx46 and to a chimeric connexin, cx32E143, which both form patent hemichannels when expressed in Xenopus oocytes. The thiol reagent maleimido-butyryl-biocytin was used to probe 12 cysteine replacement mutants in the first transmembrane segment and two in the amino-terminal segment. Maleimido-butyryl-biocytin was found to inhibit channel activity with cysteines in two equivalent positions in both connexins: 133C and M34C in cx32E143 and 134C and L35C in cx46. These two positions in the first transmembrane segment are thus accessible from the extracellular space and consequently appear to contribute to the pore lining. The data also suggest that the pore structure is complex and may involve more than one transmembrane segment.
| Original language | English |
|---|---|
| Pages (from-to) | 1946-1953 |
| Number of pages | 8 |
| Journal | Biophysical Journal |
| Volume | 72 |
| Issue number | 5 |
| State | Published - May 1 1997 |
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ASJC Scopus subject areas
- Biophysics
Cite this
Identification of a pore lining segment in gap junction hemichannels. / Zhou, Xiao Wei; Pfahnl, Arnold; Werner, Rudolf; Hudder, Alice; Llanes, Audrey; Luebke, Anne; Dahl, Gerhard.
In: Biophysical Journal, Vol. 72, No. 5, 01.05.1997, p. 1946-1953.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Identification of a pore lining segment in gap junction hemichannels
AU - Zhou, Xiao Wei
AU - Pfahnl, Arnold
AU - Werner, Rudolf
AU - Hudder, Alice
AU - Llanes, Audrey
AU - Luebke, Anne
AU - Dahl, Gerhard
PY - 1997/5/1
Y1 - 1997/5/1
N2 - The ability of certain connexins to form open hemichannels has been exploited to study the pore structure of gap junction (hemi)channels. Cysteine scanning mutagenesis was applied to cx46 and to a chimeric connexin, cx32E143, which both form patent hemichannels when expressed in Xenopus oocytes. The thiol reagent maleimido-butyryl-biocytin was used to probe 12 cysteine replacement mutants in the first transmembrane segment and two in the amino-terminal segment. Maleimido-butyryl-biocytin was found to inhibit channel activity with cysteines in two equivalent positions in both connexins: 133C and M34C in cx32E143 and 134C and L35C in cx46. These two positions in the first transmembrane segment are thus accessible from the extracellular space and consequently appear to contribute to the pore lining. The data also suggest that the pore structure is complex and may involve more than one transmembrane segment.
AB - The ability of certain connexins to form open hemichannels has been exploited to study the pore structure of gap junction (hemi)channels. Cysteine scanning mutagenesis was applied to cx46 and to a chimeric connexin, cx32E143, which both form patent hemichannels when expressed in Xenopus oocytes. The thiol reagent maleimido-butyryl-biocytin was used to probe 12 cysteine replacement mutants in the first transmembrane segment and two in the amino-terminal segment. Maleimido-butyryl-biocytin was found to inhibit channel activity with cysteines in two equivalent positions in both connexins: 133C and M34C in cx32E143 and 134C and L35C in cx46. These two positions in the first transmembrane segment are thus accessible from the extracellular space and consequently appear to contribute to the pore lining. The data also suggest that the pore structure is complex and may involve more than one transmembrane segment.
UR - http://www.scopus.com/inward/record.url?scp=0030897850&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0030897850&partnerID=8YFLogxK
M3 - Article
C2 - 9129799
AN - SCOPUS:0030897850
VL - 72
SP - 1946
EP - 1953
JO - Biophysical Journal
JF - Biophysical Journal
SN - 0006-3495
IS - 5
ER -