Downregulation of KCNQ4 by Janus Kinase 2

Downregulation of KCNQ4 by Janus Kinase 2 Janus kinase-2 (JAK2) participates in the signaling of several hormones, growth factors and cytokines. Further stimulators of JAK2 include osmotic cell shrinkage, and the kinase activates the cell volume regulatory Na+/H+ exchanger. The kinase may thus participate in cell volume regulation. Cell shrinkage is known to inhibit K+ channels. Volume-regulatory K+ channels include the voltage-gated K+ channel KCNQ4. The present study explored the effect of JAK2 on KCNQ4 channel activity. KCNQ4 was expressed in Xenopus oocytes with or without wild-type JAK2, constitutively active V617FJAK2 or inactive K882EJAK2; and cell membrane conductance was determined by dual-electrode voltage clamp. Expression of KCNQ4 was followed by the appearance of voltage-gated K+ conductance. Coexpression of JAK2 or of V617FJAK2, but not of K882EJAK2, resulted in a significant decrease in conductance. Treatment of KCNQ4 and JAK2 coexpressing oocytes with the JAK2 inhibitor AG490 (40 μM) was followed by an increase in conductance. Treatment of KCNQ4 expressing oocytes with brefeldin A (5 μM) was followed by a decrease in conductance, which was similar in oocytes expressing KCNQ4 together with JAK2 as in oocytes expressing KCNQ4 alone. Thus, JAK2 apparently does not accelerate channel protein retrieval from the cell membrane. In conclusion, JAK2 downregulates KCNQ4 activity and thus counteracts K+ exit, an effect which may contribute to cell volume regulation. The Journal of Membrane Biology Springer Journals

Loading next page...
Copyright © 2013 by Springer Science+Business Media New York
Life Sciences; Biochemistry, general; Human Physiology
Publisher site
See Article on Publisher Site


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


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.



billed annually
Start Free Trial

14-day Free Trial