PMID- 10488078
OWN - NLM
STAT- MEDLINE
DCOM- 19991104
LR  - 20210209
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 274
IP  - 39
DP  - 1999 Sep 24
TI  - Deletion of protein kinase A phosphorylation sites in the HERG potassium channel 
      inhibits activation shift by protein kinase A.
PG  - 27457-62
AB  - We investigated the role of protein kinase A (PKA) in regulation of the human
      ether-a-go-go-related gene (HERG) potassium channel activation. HERG clones with 
      single mutations destroying one of four consensus PKA phosphorylation sites
      (S283A, S890A, T895A, S1137A), as well as one clone carrying all mutations with
      no PKA phosphorylation sites (HERG 4M) were constructed. These clones were
      expressed heterologously in Xenopus oocytes, and HERG potassium currents were
      measured with the two microelectrode voltage clamp technique. Application of the 
      cAMP-specific phosphodiesterase (PDE IV) inhibitor Ro-20-1724 (100 microM), which
      results in an increased cAMP level and PKA stimulation, induced a reduction of
      HERG wild type outward currents by 19.1% due to a shift in the activation curve
      of 12.4 mV. When 100 microM Ro-20-1724 was applied to the HERG 4M channel,
      missing all PKA sites, there was no significant shift in the activation curve,
      and the current amplitude was not reduced. Furthermore, the adenylate cyclase
      activator forskolin that leads to PKA activation (400 microM, 60 min), shifted
      HERG wild type channel activation by 14.1 mV and reduced currents by 39.9%,
      whereas HERG 4M channels showed only a small shift of 4.3 mV and a weaker current
      reduction of 22.3%. We conclude that PKA regulates HERG channel activation, and
      direct phosphorylation of the HERG channel protein has a functional role that may
      be important in regulation of cardiac repolarization.
FAU - Thomas, D
AU  - Thomas D
AD  - Department of Cardiology, Medical University Hospital Heidelberg,
      Bergheimerstrasse 58, D-69115 Heidelberg, Germany.
FAU - Zhang, W
AU  - Zhang W
FAU - Karle, C A
AU  - Karle CA
FAU - Kathofer, S
AU  - Kathofer S
FAU - Schols, W
AU  - Schols W
FAU - Kubler, W
AU  - Kubler W
FAU - Kiehn, J
AU  - Kiehn J
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Cation Transport Proteins)
RN  - 0 (DNA-Binding Proteins)
RN  - 0 (ERG protein, human)
RN  - 0 (ERG1 Potassium Channel)
RN  - 0 (Ether-A-Go-Go Potassium Channels)
RN  - 0 (KCNH2 protein, human)
RN  - 0 (KCNH6 protein, human)
RN  - 0 (Potassium Channels)
RN  - 0 (Potassium Channels, Voltage-Gated)
RN  - 0 (Recombinant Proteins)
RN  - 0 (Trans-Activators)
RN  - 0 (Transcriptional Regulator ERG)
RN  - 1F7A44V6OU (Colforsin)
RN  - 29925-17-5 (4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone)
RN  - EC 2.7.11.11 (Cyclic AMP-Dependent Protein Kinases)
SB  - IM
MH  - 4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone/pharmacology
MH  - Amino Acid Sequence
MH  - Amino Acid Substitution
MH  - Animals
MH  - *Cation Transport Proteins
MH  - Cell Membrane/drug effects/physiology
MH  - Colforsin/pharmacology
MH  - Consensus Sequence
MH  - Cyclic AMP-Dependent Protein Kinases/*metabolism
MH  - *DNA-Binding Proteins
MH  - ERG1 Potassium Channel
MH  - Ether-A-Go-Go Potassium Channels
MH  - Female
MH  - Humans
MH  - Membrane Potentials/drug effects/physiology
MH  - Models, Molecular
MH  - Mutagenesis, Site-Directed
MH  - Oocytes/physiology
MH  - Phosphorylation
MH  - Potassium Channels/chemistry/*physiology
MH  - *Potassium Channels, Voltage-Gated
MH  - Protein Folding
MH  - Recombinant Proteins/chemistry/metabolism
MH  - Sequence Deletion
MH  - *Trans-Activators
MH  - Transcriptional Regulator ERG
MH  - Xenopus laevis
EDAT- 1999/09/17 00:00
MHDA- 1999/09/17 00:01
CRDT- 1999/09/17 00:00
PHST- 1999/09/17 00:00 [pubmed]
PHST- 1999/09/17 00:01 [medline]
PHST- 1999/09/17 00:00 [entrez]
AID - 10.1074/jbc.274.39.27457 [doi]
AID - S0021-9258(19)52141-X [pii]
PST - ppublish
SO  - J Biol Chem. 1999 Sep 24;274(39):27457-62. doi: 10.1074/jbc.274.39.27457.