Abstract
In avian smooth muscles, GTPγS produces a Rho kinase mediated increase in PHI-1 phosphorylation and force, but whether this correlation is causal is unknown. We examined the effect of phosphorylated PHI-1 (P-PHI-1) on force and myosin light chain (MLC20) phosphorylation at a constant [Ca2+]. P-PHI-1, but not PHI-1, increased MLC20 phosphorylation and force, and phosphorylation of PHI-1 increased the interaction of PHI-1 with PP1c. Microcystin induced a dose-dependent reduction in the binding of PHI-1 to PP1c. These results suggest PHI-1 inhibits myosin light chain phosphatase by interacting with the active site of PP1c to produce a Ca2+ independent increase in MLC20 phosphorylation and force.
Original language | English (US) |
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Pages (from-to) | 5779-5784 |
Number of pages | 6 |
Journal | FEBS Letters |
Volume | 580 |
Issue number | 24 |
DOIs | |
State | Published - Oct 16 2006 |
Keywords
- Ca sensitization
- Chicken gizzard
- MYPT1
- Myosin light chain phosphatase
- PHI-1
- PP1c
ASJC Scopus subject areas
- Biophysics
- Structural Biology
- Biochemistry
- Molecular Biology
- Genetics
- Cell Biology