Neurons and β-Cells of the Pancreas Express Connexin36, Forming Gap Junction Channels that Exhibit Strong Cationic Selectivity

Neurons and β-Cells of the Pancreas Express Connexin36, Forming Gap Junction Channels that... We examined the permeability of connexin36 (Cx36) homotypic gap junction (GJ) channels, expressed in neurons and β-cells of the pancreas, to dyes differing in molecular mass and net charge. Experiments were performed in HeLa cells stably expressing Cx36 tagged with EGFP by combining a dual whole-cell voltage clamp and fluorescence imaging. To assess the permeability of the single GJ channel (P γ), we used a dual-mode excitation of fluorescent dyes that allowed us to measure cell-to-cell dye transfer at levels not resolvable using whole-field excitation solely. We demonstrate that P γ of Cx36 for cationic dyes (EAM-1+ and EAM-2+) is ~10-fold higher than that for an anionic dye of the same net charge and similar molecular mass, Alexa fluor-350 (AFl-350−). In addition, P γ for Lucifer yellow (LY2−) is approximately fourfold smaller than that for AFl-350−, which suggests that the higher negativity of LY2− significantly reduces permeability. The P γ of Cx36 for AFl-350 is approximately 358, 138, 23 and four times smaller than the P γs of Cx43, Cx40, Cx45, and Cx57, respectively. In contrast, it is 6.5-fold higher than the P γ of mCx30.2, which exhibits a smaller single-channel conductance. Thus, Cx36 GJs are highly cation-selective and should exhibit relatively low permeability to numerous vital negatively charged metabolites and high permeability to K+, a major charge carrier in cell–cell communication. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png The Journal of Membrane Biology Springer Journals

Neurons and β-Cells of the Pancreas Express Connexin36, Forming Gap Junction Channels that Exhibit Strong Cationic Selectivity

Loading next page...
 
/lp/springer_journal/neurons-and-cells-of-the-pancreas-express-connexin36-forming-gap-2dbJfuAZWr
Publisher
Springer-Verlag
Copyright
Copyright © 2012 by Springer Science+Business Media, LLC
Subject
Life Sciences; Biochemistry, general; Human Physiology
ISSN
0022-2631
eISSN
1432-1424
D.O.I.
10.1007/s00232-012-9445-3
Publisher site
See Article on Publisher Site

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches

$49/month

Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.

$588

$360/year

billed annually
Start Free Trial

14-day Free Trial