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A Small Molecule Pyrazolo[3,4-d]pyrimidinone Inhibitor of Zipper-Interacting Protein Kinase Suppresses Calcium Sensitization of Vascular Smooth Muscle.

MacDonald, Justin A; Sutherland, Cindy; Carlson, David A; Bhaidani, Sabreena; Al-Ghabkari, Abdulhameed; Swärd, Karl LU ; Haystead, Timothy Aj and Walsh, Michael P (2016) In Molecular Pharmacology 89(1). p.105-117
Abstract
A novel inhibitor of zipper-interacting protein kinase (ZIPK) was utilized to examine the involvement of ZIPK in the regulation of smooth muscle contraction. Pre-treatment of de-endothelialized rat caudal arterial smooth muscle strips with the pyrazolo[3,4-d]pyrimidinone inhibitor HS38 decreased the velocity of contraction (time to reach half-maximal force) induced by the phosphatase inhibitor calyculin A in the presence of Ca2+ without affecting maximal force development. This effect was reversed following washout of HS38 and correlated with a reduction in the rate of phosphorylation of LC20 (myosin 20-kDa regulatory light chains) but not of CPI-17 (protein kinase C-potentiated inhibitory protein for myosin phosphatase of 17 kDa), Par-4... (More)
A novel inhibitor of zipper-interacting protein kinase (ZIPK) was utilized to examine the involvement of ZIPK in the regulation of smooth muscle contraction. Pre-treatment of de-endothelialized rat caudal arterial smooth muscle strips with the pyrazolo[3,4-d]pyrimidinone inhibitor HS38 decreased the velocity of contraction (time to reach half-maximal force) induced by the phosphatase inhibitor calyculin A in the presence of Ca2+ without affecting maximal force development. This effect was reversed following washout of HS38 and correlated with a reduction in the rate of phosphorylation of LC20 (myosin 20-kDa regulatory light chains) but not of CPI-17 (protein kinase C-potentiated inhibitory protein for myosin phosphatase of 17 kDa), Par-4 (prostate apoptosis response-4) or MYPT1 (myosin phosphatase targeting subunit 1), all of which have been implicated in the regulation of vascular contractility. A structural analog of HS38, with inhibitory activity towards PIM3 kinase but not ZIPK, had no effect on calyculin A-induced contraction or protein phosphorylations. We conclude that a pool of constitutively-active ZIPK is involved in regulation of vascular smooth muscle contraction through direct phosphorylation of LC20 upon inhibition of myosin light chain phosphatase activity. HS38 also significantly attenuated both phasic and tonic contractile responses elicited by phenylephrine, angiotensin II, endothelin-1, U46619 and K+-induced membrane depolarization in the presence of Ca2+, which correlated with inhibition of phosphorylation of LC20, MYPT1 and CPI-17. These effects of HS38 suggest that ZIPK also lies downstream of G protein-coupled receptors that signal through both Gα12/13 and Gαq/11. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Molecular Pharmacology
volume
89
issue
1
pages
105 - 117
publisher
American Society for Pharmacology and Experimental Therapeutics
external identifiers
  • pmid:26464323
  • wos:000366672200010
  • scopus:84958177070
ISSN
1521-0111
DOI
10.1124/mol.115.100529
language
English
LU publication?
yes
id
06be4574-1878-40e6-a9fb-88c8fabac3d9 (old id 8152412)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/26464323?dopt=Abstract
date added to LUP
2015-11-03 12:47:37
date last changed
2017-07-09 03:07:55
@article{06be4574-1878-40e6-a9fb-88c8fabac3d9,
  abstract     = {A novel inhibitor of zipper-interacting protein kinase (ZIPK) was utilized to examine the involvement of ZIPK in the regulation of smooth muscle contraction. Pre-treatment of de-endothelialized rat caudal arterial smooth muscle strips with the pyrazolo[3,4-d]pyrimidinone inhibitor HS38 decreased the velocity of contraction (time to reach half-maximal force) induced by the phosphatase inhibitor calyculin A in the presence of Ca2+ without affecting maximal force development. This effect was reversed following washout of HS38 and correlated with a reduction in the rate of phosphorylation of LC20 (myosin 20-kDa regulatory light chains) but not of CPI-17 (protein kinase C-potentiated inhibitory protein for myosin phosphatase of 17 kDa), Par-4 (prostate apoptosis response-4) or MYPT1 (myosin phosphatase targeting subunit 1), all of which have been implicated in the regulation of vascular contractility. A structural analog of HS38, with inhibitory activity towards PIM3 kinase but not ZIPK, had no effect on calyculin A-induced contraction or protein phosphorylations. We conclude that a pool of constitutively-active ZIPK is involved in regulation of vascular smooth muscle contraction through direct phosphorylation of LC20 upon inhibition of myosin light chain phosphatase activity. HS38 also significantly attenuated both phasic and tonic contractile responses elicited by phenylephrine, angiotensin II, endothelin-1, U46619 and K+-induced membrane depolarization in the presence of Ca2+, which correlated with inhibition of phosphorylation of LC20, MYPT1 and CPI-17. These effects of HS38 suggest that ZIPK also lies downstream of G protein-coupled receptors that signal through both Gα12/13 and Gαq/11.},
  author       = {MacDonald, Justin A and Sutherland, Cindy and Carlson, David A and Bhaidani, Sabreena and Al-Ghabkari, Abdulhameed and Swärd, Karl and Haystead, Timothy Aj and Walsh, Michael P},
  issn         = {1521-0111},
  language     = {eng},
  number       = {1},
  pages        = {105--117},
  publisher    = {American Society for Pharmacology and Experimental Therapeutics},
  series       = {Molecular Pharmacology},
  title        = {A Small Molecule Pyrazolo[3,4-d]pyrimidinone Inhibitor of Zipper-Interacting Protein Kinase Suppresses Calcium Sensitization of Vascular Smooth Muscle.},
  url          = {http://dx.doi.org/10.1124/mol.115.100529},
  volume       = {89},
  year         = {2016},
}