SUMOylation determines the voltage required to activate cardiac IKs channels [Physiology]
![SUMOylation determines the voltage required to activate cardiac IKs channels [Physiology]](/image/eyJ1cmkiOiJodHRwOi8vc3RhY2thZGVtaWMuaGVyb2t1YXBwLmNvbS9pbWFnZT9pbWFnZV9pZD04MTA4IiwiZm9ybWF0Ijoid2VicCIsInF1YWxpdHkiOjEwMCwibm9DYWNoZSI6dHJ1ZX0=.webp)
IKs channels open in response to depolarization of the membrane voltage during the cardiac action potential, passing potassium ions outward to repolarize ventricular myocytes and end each beat. Here, we show that the voltage required to activate IKs channels depends on their covalent modification by small ubiquitin-like modifier (SUMO) proteins. IKs channels are comprised of four KCNQ1 pore-forming subunits, two KCNE1 accessory subunits, and up to four SUMOs, one on Lys424 of each KCNQ1 subunit. Each SUMO shifts the half-maximal activation voltage (V1/2) of IKs ∼ +8 mV, producing a maximal +34-mV shift in neonatal mouse cardiac myocytes or Chinese hamster ovary (CHO) cells expressing the mouse or human subunits. Unexpectedly, channels formed without KCNE1 carry at most two SUMOs despite having four available KCNQ1-Lys424 sites. SUMOylation of KCNQ1 is KCNE1 dependent and determines the native attributes of cardiac IKs in vivo.
Publisher URL: http://feedproxy.google.com/~r/Pnas-RssFeedOfEarlyEditionArticles/~3/Xh-rNj31Ip0/1706267114.short
DOI: 10.1073/pnas.1706267114
Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.
Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.