Myosin light chain kinase occurs in bullfrog sympathetic neurons and may modulate voltage-dependent potassium currents.
A polyclonal antibody against myosin light chain kinase (MLCK) of chicken gizzard recognized a 130 kd peptide of bullfrog sympathetic ganglia as MLCK. MLCK immunoreactivity was confined to the neuronal cell body. A synthetic peptide corresponding to an inhibitory domain of MLCK (Ala783-Gly804) was applied intracellularly to isolated sympathetic neurons during whole-cell recordings of ionic currents. The peptide inhibitor reversibly decreased M-type potassium current (IM) while not affecting A-type of delayed rectifier-type potassium currents. Intracellular application of an active fragment of MLCK enhanced IM, whereas application of an inactive MLCK fragment did not. The results suggest that IM can be modulated by MLCK-catalyzed phosphorylation.
Akasu
T
T
Department of Physiology, Kurume University School of Medicine, Japan.
Ito
M
M
Nakano
T
T
Schneider
C R
CR
Simmons
M A
MA
Tanaka
T
T
Tokimasa
T
T
Yoshida
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001464:Barium / Q000494:pharmacology; D015153:Blotting, Western; D002645:Chickens; D005728:Ganglia, Sympathetic / Q000502:physiology*; D005895:Gizzard, Avian / Q000201:enzymology; D007150:Immunohistochemistry; D008564:Membrane Potentials / Q000187:drug effects; D008969:Molecular Sequence Data; D009116:Muscarine / Q000494:pharmacology; D009130:Muscle, Smooth / Q000201:enzymology; D009219:Myosin-Light-Chain Kinase / Q000032:analysis / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D010446:Peptide Fragments / Q000138:chemical synthesis / Q000494:pharmacology; D010455:Peptides / Q000138:chemical synthesis / Q000494:pharmacology*; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D011892:Rana catesbeiana; D014446:Tyrosine 3-Monooxygenase / Q000032:analysis
D010446:Peptide Fragments; D010455:Peptides; D015221:Potassium Channels; D001464:Barium; D009116:Muscarine; D014446:Tyrosine 3-Monooxygenase; D009219:Myosin-Light-Chain Kinase