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Phosphorylation of the Small Heat Shock-related Protein, HSP20, in Vascular Smooth Muscles Is Associated with Changes in the Macromolecular Associations of HSP20
Cyclic nucleotide-dependent vasorelaxation is associated with increases in the phosphorylation of a small heat shock-related protein, HSP20. We hypothesized that phosphorylation of HSP20 in vascular smooth muscles is associated with alterations in the macromolecular associations of HSP20. Treatment...
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Published in: | The Journal of biological chemistry 1999-03, Vol.274 (10), p.6324-6329 |
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Main Authors: | , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | Cyclic nucleotide-dependent vasorelaxation is associated with increases in the phosphorylation of a small heat shock-related
protein, HSP20. We hypothesized that phosphorylation of HSP20 in vascular smooth muscles is associated with alterations in
the macromolecular associations of HSP20. Treatment of bovine carotid artery smooth muscles with the phosphodiesterase inhibitor,
3-isobutyl-1-methylxanthine, and the adenylate cyclase activator, forskolin, led to increases in the phosphorylation of HSP20
and dissociation of macromolecular aggregates of HSP20. However, 3-isobutyl-1-methylxanthine and forskolin treatment of a
muscle that is uniquely refractory to cyclic nucleotide-dependent vasorelaxation, human umbilical artery smooth muscle, did
not result in increases in the phosphorylation of HSP20 or to dissociation of macromolecular aggregates. HSP20 can be phosphorylated
in vitro by the catalytic subunit of cAMP-dependent protein kinase (PKA) in both carotid and umbilical arteries and this phosphorylation
of HSP20 is associated with dissociation of macromolecular aggregates of HSP20. Activation of cyclic nucleotide-dependent
signaling pathways does not lead to changes in the macromolecular associations of another small heat shock protein, HSP27.
Interestingly, the myosin light chains (MLC 20 ) are in similar fractions as the HSP20, and phosphorylation of HSP20 is associated with changes in the macromolecular associations
of MLC 20 . These data suggest that increases in the phosphorylation of HSP20 are associated with changes in the macromolecular associations
of HSP20. HSP20 may regulate vasorelaxation through a direct interaction with specific contractile regulatory proteins. |
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ISSN: | 0021-9258 1083-351X |
DOI: | 10.1074/jbc.274.10.6324 |