Dual regulation of the ATP-sensitive potassium channel by activation of cGMP-dependent protein kinase

Yongping Chai, Yu-Fung Lin

Research output: Contribution to journalArticlepeer-review

24 Scopus citations


Adenosine triphosphate (ATP)-sensitive potassium (KATP) channels couple cellular metabolic status to membrane electrical activity. In this study, we performed patch-clamp recordings to investigate how cyclic guanosine monophosphate (cGMP)-dependent protein kinase (PKG) regulates the function of KATP channels, using both transfected human SH-SY5Y neuroblastoma cells and embryonic kidney (HEK) 293 cells. In intact SH-SY5Y cells, the single-channel currents of Kir6.2/sulfonylurea receptor (SUR) 1 channels, a neuronal-type KATP isoform, were enhanced by zaprinast, a cGMP-specific phosphodiesterase inhibitor; this enhancement was abolished by inhibition of PKG, suggesting a stimulatory role of cGMP/PKG signaling in regulating the function of neuronal KATP channels. Similar effects of cGMP accumulation were confirmed in intact HEK293 cells expressing Kir6.2/SUR1 channels. In contrast, direct application of purified PKG suppressed rather than activated Kir6.2/SUR1 channels in excised, inside-out patches, while tetrameric Kir6.2LRKR368/369/370/371AAAA channels expressed without the SUR subunit were not modulated by zaprinast or purified PKG. Lastly, reconstitution of the soluble guanylyl cyclase/cGMP/PKG signaling pathway by generation of nitric oxide led to Kir6.2/SUR1 channel activation in both cell types. Taken together, here, we report novel findings that PKG exerts dual functional regulation of neuronal KATP channels in a SUR subunit-dependent manner, which may provide new means of therapeutic intervention for manipulating neuronal excitability and/or survival.

Original languageEnglish (US)
Pages (from-to)897-915
Number of pages19
JournalPflugers Archiv European Journal of Physiology
Issue number5
StatePublished - Aug 2008


  • K channel
  • Nitric oxide
  • Patch clamp
  • Phosphorylation
  • Protein kinase G
  • Signal transduction
  • Single channel

ASJC Scopus subject areas

  • Physiology


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