Quantitative measurements of Ca(2+)/calmodulin binding and activation of myosin light chain kinase in cells.
Article Details
- CitationCopy to clipboard
Geguchadze R, Zhi G, Lau KS, Isotani E, Persechini A, Kamm KE, Stull JT
Quantitative measurements of Ca(2+)/calmodulin binding and activation of myosin light chain kinase in cells.
FEBS Lett. 2004 Jan 16;557(1-3):121-4.
- PubMed ID
- 14741352 [ View in PubMed]
- Abstract
Myosin II regulatory light chain (RLC) phosphorylation by Ca(2+)/calmodulin (CaM)-dependent myosin light chain kinase (MLCK) is implicated in many cellular actin cytoskeletal functions. We examined MLCK activation quantitatively with a fluorescent biosensor MLCK where Ca(2+)-dependent increases in kinase activity were coincident with decreases in fluorescence resonance energy transfer (FRET) in vitro. In cells stably transfected with CaM sensor MLCK, increasing [Ca(2+)](i) increased MLCK activation and RLC phosphorylation coincidently. There was no evidence for CaM binding but not activating MLCK at low [Ca(2+)](i). At saturating [Ca(2+)](i) MLCK was not fully activated probably due to limited availability of cellular Ca(2+)/CaM.