TY - JOUR
T1 - Association of myosin light chain kinase with lymphocyte membrane cytoskeleton complex
AU - Bourguignon, Lilly Y.W.
AU - Nagpal, Madan L.
AU - Balazovich, Kenneth
AU - Guerriero, Vlnce
AU - Means, Anthony R.
PY - 1982/12/1
Y1 - 1982/12/1
N2 - A specific antibody against myosin light chain kinase (MLCK) was used to identify the presence of a Ca2+-calmodulin-activated MLCK in mouse T-lymphoma cells. With a double immunofluorescence technique, MLCK was determined to be accumulated directly under Con A-capped structures in a manner similar to that of previously described accumulation of actomyosin. The lymphocyte MLCK was phosphorylated in the uncapped cell and, by immunoprecipitation with a specific MLCK antibody, was shown to possess a Mr of 130,000. The MLCK was also found to constitute a major fraction of the phosphoproteins present in the plasma membrane associated-cytoskeleton. Myosin light chain kinase catalyzed the phosphorylation of both endogenous lymphocyte myosin light chains and those from smooth and skeletal muscle. The enzyme activity was dependent on the presence of Ca2+-calmodulin and was inhibited by the calmodulin-binding drug, trifluoperazine. These data suggest that the membrane-cytoskeleton-associated MLCK activity may be important in regulation of the actinmyosin contraction which is believed to be required for the collection of surface receptors into capped structures.
AB - A specific antibody against myosin light chain kinase (MLCK) was used to identify the presence of a Ca2+-calmodulin-activated MLCK in mouse T-lymphoma cells. With a double immunofluorescence technique, MLCK was determined to be accumulated directly under Con A-capped structures in a manner similar to that of previously described accumulation of actomyosin. The lymphocyte MLCK was phosphorylated in the uncapped cell and, by immunoprecipitation with a specific MLCK antibody, was shown to possess a Mr of 130,000. The MLCK was also found to constitute a major fraction of the phosphoproteins present in the plasma membrane associated-cytoskeleton. Myosin light chain kinase catalyzed the phosphorylation of both endogenous lymphocyte myosin light chains and those from smooth and skeletal muscle. The enzyme activity was dependent on the presence of Ca2+-calmodulin and was inhibited by the calmodulin-binding drug, trifluoperazine. These data suggest that the membrane-cytoskeleton-associated MLCK activity may be important in regulation of the actinmyosin contraction which is believed to be required for the collection of surface receptors into capped structures.
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U2 - 10.1083/jcb.95.3.793
DO - 10.1083/jcb.95.3.793
M3 - Article
C2 - 6984047
AN - SCOPUS:0020446220
SN - 0021-9525
VL - 95
SP - 793
EP - 797
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 3
ER -