Up-Regulation of hERG K+ Channels by B-RAF

نویسندگان

  • Tatsiana Pakladok
  • Zohreh Hosseinzadeh
  • Ahmad Almilaji
  • Aleksandra Lebedeva
  • Ekaterina Shumilina
  • Ioana Alesutan
  • Florian Lang
چکیده

Human ether-a-go-go related-gene K⁺ channels (hERG) participate in the regulation of tumor cell proliferation and apoptosis. HERG channel activity is up-regulated by growth factors. Kinases sensitive to growth factor signaling include the serine/threonine protein kinase B-RAF. The present study thus explored whether B-RAF influences hERG channel expression and activity. To this end, hERG channels were expressed in Xenopus oocytes with or without wild-type B-RAF, hERG channel activity was determined utilizing dual-electrode voltage clamp and hERG protein abundance in the cell membrane was analyzed utilizing confocal microscopy as well as chemiluminescence. Moreover, in rhabdomyosarcoma RD cells the effect of B-RAF inhibitor PLX-4720 on hERG-mediated current was quantified by whole-cell patch clamp and hERG cell surface protein abundance by utilizing biotinylation of cell surface proteins as well as flow cytometry. As a result, co-expression of wild-type B-RAF in hERG-expressing Xenopus oocytes significantly increased hERG channel activity and hERG channel protein abundance in the cell membrane. Treatment for 24 hours of B-RAF and hERG-expressing Xenopus oocytes with B-RAF inhibitor PLX-4720 (10 µM) significantly decreased hERG-mediated current and hERG cell surface expression. Similarly, in rhabdomyosarcoma RD cells, treatment for 24 hours with B-RAF inhibitor PLX-4720 significantly decreased hERG cell membrane protein abundance and hERG-mediated current. In conclusion, B-RAF is a powerful regulator of hERG channel activity and cell surface hERG protein abundance.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

PIKfyve sensitivity of hERG channels.

BACKGROUND/AIMS Human ether-a-go-go (hERG) channels contribute to cardiac repolarization and participate in the regulation of tumor cell proliferation. Mutations in hERG channels may cause long QT syndrome and sudden cardiac death due to ventricular arrhythmias. HERG channel activity is up-regulated by the serum- and glucocorticoid-inducible kinase isoforms SGK1 and SGK3. Related kinases are pr...

متن کامل

Interaction between the cardiac rapidly (IKr) and slowly (IKs) activating delayed rectifier potassium channels revealed by low K+-induced hERG endocytic degradation.

Cardiac repolarization is controlled by the rapidly (I(Kr)) and slowly (I(Ks)) activating delayed rectifier potassium channels. The human ether-a-go-go-related gene (hERG) encodes I(Kr), whereas KCNQ1 and KCNE1 together encode I(Ks). Decreases in I(Kr) or I(Ks) cause long QT syndrome (LQTS), a cardiac disorder with a high risk of sudden death. A reduction in extracellular K(+) concentration ([K...

متن کامل

Regulation of the human ether-a-go-go-related gene (hERG) channel by Rab4 protein through neural precursor cell-expressed developmentally down-regulated protein 4-2 (Nedd4-2).

The human ether-a-go-go-related gene (hERG) encodes the pore-forming α-subunit of the rapidly activating delayed rectifier K(+) channel in the heart, which plays a critical role in cardiac action potential repolarization. Dysfunction of IKr causes long QT syndrome, a cardiac electrical disorder that predisposes affected individuals to fatal arrhythmias and sudden death. The homeostasis of hERG ...

متن کامل

Differential Effects of Ginsenoside Metabolites on HERG K+ Channel Currents

The human ether-a-go-go-related gene (HERG) cardiac K(+) channels are one of the representative pharmacological targets for development of drugs against cardiovascular diseases such as arrhythmia. Panax ginseng has been known to exhibit cardioprotective effects. In a previous report we demonstrated that ginsenoside Rg3 regulates HERG K(+) channels by decelerating deactivation. However, little i...

متن کامل

Upregulation of HERG channels by the serum and glucocorticoid inducible kinase isoform SGK3.

Human ether-a-go-go (HERG) channels participate in the repolarization of the cardiac action potential. Loss of function mutations of HERG lead to delayed cardiac repolarization reflected by prolonged QT interval. HERG channels are regulated through a signaling cascade involving phosphatidylinositol 3 (PI3) kinase. Downstream targets of PI3 kinase include the serum and glucocorticoid inducible k...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره 9  شماره 

صفحات  -

تاریخ انتشار 2014