Myosin light chain kinase binding to actin filaments.
Smooth muscle myosin light chain kinase (MLCK) plays important roles in contractile-motile processes of a variety of cells. Three DFRxxL motifs at the kinase N-terminus (residues 2-63) are critical for high-affinity binding to actin-containing filaments [Smith et al. (1999) J. Biol. Chem. 274, 29433-29438]. A GST fusion protein containing residues 1-75 of MLCK (GST75-MLCK) bound maximally to both smooth muscle myofilaments and F-actin at 0.28 and 0.31 mol GST75-MLCK/mol actin with respective K(D) values of 0.1 microM and 0.8 microM. High-affinity binding of MLCK to actin-containing filaments may be due to each DFRxxL motif binding to one actin monomer in filaments.
Smith
L
L
Department of Physiology, The University of Texas Southwestern Medical Center at Dallas, 75390-9040, USA.
Stull
J T
JT
D008841:Actin Cytoskeleton / Q000378:metabolism*; D000199:Actins / Q000378:metabolism*; D020816:Amino Acid Motifs; D000818:Animals; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D009130:Muscle, Smooth / Q000201:enzymology; D009219:Myosin-Light-Chain Kinase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D000199:Actins; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; D009219:Myosin-Light-Chain Kinase