Related Experiment Video

Updated: Aug 6, 2026

A Functional Assay for Gap Junctional Examination; Electroporation of Adherent Cells on Indium-Tin Oxide
11:02

A Functional Assay for Gap Junctional Examination; Electroporation of Adherent Cells on Indium-Tin Oxide

Published on: October 18, 2014

v-Src tyrosine phosphorylation of connexin43: regulation of gap junction communication and effects on cell

Rui Lin1, Kendra D Martyn, Carrie V Guyette

  • 1Department of Immunology, The Scripps Research Institute, La Jolla, California, USA.

Cell Communication & Adhesion
|August 19, 2006
PubMed

Insights

Tyrosine phosphorylation of connexin43 (Cx43) by v-Src disrupts gap junctional communication (GJC). However, this disruption does not involve negative charge changes or affect cell migration, adhesion, or proliferation in cancer cells.

Area of Science:

  • Cell Biology
  • Biochemistry
  • Oncology

Background:

  • The oncogenic tyrosine kinase v-Src phosphorylates connexin43 (Cx43) at tyrosine residues Y247 and Y265.
  • This phosphorylation event is known to inhibit Cx43-mediated gap junctional communication (GJC), crucial for intercellular exchange.

Purpose of the Study:

  • To investigate the role of negative charge introduced by tyrosine phosphorylation in v-Src's inhibition of Cx43 GJC.
  • To determine if mitogen-activated protein (MAP) kinase phosphorylation of Cx43 is necessary for v-Src-induced GJC disruption.
  • To assess the involvement of Cx43 tyrosine phosphorylation and GJC disruption in v-Src-mediated transformed cell properties.

Main Methods:

  • Expressing Cx43 with glutamic acid substitutions (Y247E or Y265E) to mimic negative charge.
  • Utilizing Cx43 knockout fibroblasts to test channel functionality.
  • Employing a triple serine to alanine mutant (Cx43S255/279/282A) to assess MAP kinase phosphorylation.
  • Using v-Src-resistant Cx43 mutants (Cx43Y247/265F) to evaluate transformed cell phenotypes.

Main Results:

  • Cx43Y247E and Cx43Y265E channels were functional, indicating negative charge is not the primary mechanism for v-Src's GJC inhibition.
  • v-Src-induced GJC disruption was confirmed to be dependent on tyrosine phosphorylation and independent of MAP kinase phosphorylation.
  • Cx43Y247/265F cells exhibited transformed properties (migration, adhesion, proliferation) similar to Cx43wt/v-Src cells.

Conclusions:

  • The disruption of Cx43 GJC by v-Src is not mediated by the introduction of a negative charge at Y247 or Y265.
  • Tyrosine phosphorylation of Cx43 by v-Src is sufficient to disrupt GJC, and MAP kinase phosphorylation is not required.
  • Cx43 tyrosine phosphorylation and subsequent GJC inhibition are not responsible for the altered cell migration, adhesion, and proliferation observed in v-Src-transformed cells.

More Related Videos

Perturbing Endothelial Biomechanics via Connexin 43 Structural Disruption09:20

Perturbing Endothelial Biomechanics via Connexin 43 Structural Disruption

Published on: October 4, 2019

Biotinylated Cell-penetrating Peptides to Study Intracellular Protein-protein Interactions10:26

Biotinylated Cell-penetrating Peptides to Study Intracellular Protein-protein Interactions

Published on: December 20, 2017

Related Concept Videos

Gap Junctions01:27

Gap Junctions

The cytoplasm of adjacent animal cells can exchange small molecules, ions, and secondary messengers via the communication channels which form the gap junctions. These junctions comprise a few hundred to thousands of molecular channels, each made of two halves, called the connexon hemichannel. A connexon is a hexamer of six transmembrane connexin proteins, which assemble radially, thus forming a pore or channel in the center. One connexon hemichannel docks with a corresponding connexon on the...
Gap Junctions01:37

Gap Junctions

Multicellular organisms employ a variety of ways for cells to communicate with each other. Gap junctions are specialized proteins that form pores between neighboring cells in animals, connecting the cytoplasm between the two, and allowing for the exchange of molecules and ions. They are found in a wide range of invertebrate and vertebrate species, mediate numerous functions including cell differentiation and development, and are associated with numerous human diseases, including cardiac and...
Receptor Tyrosine Kinases01:26

Receptor Tyrosine Kinases

Receptor tyrosine kinases or RTKs are membrane-bound receptors that phosphorylate specific tyrosine on protein substrates. RTKs regulate cellular growth, differentiation, survival, and migration. They contain an extracellular ligand binding domain, a transmembrane domain, and a cytosolic tail with intrinsic kinase activity. Several extracellular signaling molecules activate RTKs in one or more ways and relay the signal downstream. Ligands such as platelet-derived growth factor (PDGF) or...
Intracellular Signaling Affects Focal Adhesions01:17

Intracellular Signaling Affects Focal Adhesions

Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Tension Response at Adherens Junctions01:26

Tension Response at Adherens Junctions

The adherens junctions that anchor cells together are multi-protein complexes that dynamically adapt to mechanical stimuli such as tensile forces and shear stress. Mechanosensory proteins in these junctions can sense such mechanical stimuli and undergo a shift in their conformation, resulting in an altered function — a process called mechanotransduction.
α-Catenin as a Mechanosensory Protein
The α-catenin of adherens junctions is an allosteric protein with three VH (vinculin homology) domains...
Contact-dependent Signaling01:19

Contact-dependent Signaling

Contact-dependent signaling, as the name suggests, requires that communicating cells be in direct contact with each other. This is achieved either through receptor-ligand interactions or by specialized cytoplasmic channels that allow the flow of small molecules between cells. In animal cells, channels called gap junctions facilitate contact-dependent signaling in certain tissues, whereas, plasmodesmata perform a similar function in plants.
Gap Junctions
In animal cells, gap junctions are formed...