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Functional analysis of selective interactions among rodent connexins
T W White1, D L Paul, D A Goodenough
1Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Molecular Biology of the Cell
|April 1, 1995
Summary
Cell communication depends on connexin (Cx) protein interactions. This study reveals Cx40 and Cx46 exhibit specific pairing preferences, with extracellular domains influencing compatibility and internal sequences affecting voltage gating.
Area of Science:
- Cell biology
- Biophysics
- Molecular biology
Background:
- Gap junctions mediate direct cell-to-cell communication.
- Diverse connexin (Cx) proteins form these junctions.
- Heterotypic junctions (mixed connexin content) raise questions about compatibility.
Purpose of the Study:
- To systematically examine communication between cells expressing different connexins.
- To identify the molecular basis of connexin compatibility and voltage gating.
Main Methods:
- Co-expression of various connexins in adjacent cells.
- Functional assessment of intercellular communication.
- Construction and analysis of a Cx32/Cx43 chimera.
Main Results:
- Connexins exhibit specific interaction preferences for forming heterotypic channels.
- Connexin40 (Cx40) showed restricted interactions, while Connexin46 (Cx46) interacted broadly.
- The chimera's selectivity resembled Cx43, while voltage dependence resembled Cx32.
Conclusions:
- The second extracellular domain influences connexin compatibility.
- Sequences between the N-terminus and second transmembrane domain impact voltage gating.
- Connexin interactions are specific and molecularly determined.