TY - JOUR
T1 - Myosin light chain kinase (210 kDa) is a potential cytoskeleton integrator through its unique N-terminal domain
AU - Kudryashov, Dmitry S.
AU - Stepanova, Olga V.
AU - Vilitkevich, Elena L.
AU - Nikonenko, Tatyana A.
AU - Nadezhdina, Elena S.
AU - Shanina, Nina A.
AU - Lukas, Thomas J.
AU - Van Eldik, Linda J.
AU - Watterson, D. Martin
AU - Shirinsky, Vladimir P.
N1 - Funding Information:
We are grateful to Dr. Elena A. Goncharova and Elena Yu. Kudryashova for the assistance with preliminary experiments. This work was supported by the following grants to V.S.P.: HHMI 55000335 CRDF RU-B1-2576-MO-04 and RFBR 02-04-49341.
PY - 2004/8/15
Y1 - 2004/8/15
N2 - Recently discovered 210-kDa myosin light chain kinase (MLCK-210) is identical to 108-130 kDa MLCK, the principal regulator of the myosin II molecular motor, except for the presence of a unique amino terminal extension. Our in vitro experiments and transfected cell studies demonstrate that the N-terminal half of MLCK-210 unique tail domain has novel microfilament and microtubule binding activity. Consistent with this activity, the MLCK-210 domain codistributes with microfilaments and microtubules in cultured cells and with soluble tubulin in nocodazole-treated cells. This domain is capable of aggregating tubulin dimers in vitro, causing bundling and branching of microtubules induced by taxol. The N-terminal actin-binding region of MLCK-210 has lower affinity to actin (Kd = 7.4 μM) than its central D(F/V)RXXL repeat-based actin-binding site and does not protect stress fibers from disassembly triggered by MLCK inhibition in transfected cells. Obtained results suggest that while being resident on microfilaments, MLCK-210 may interact with other cytoskeletal components through its N-terminal domain. Based on available evidence, we propose a model in which MLCK-210 could organize cell motility by simultaneous control of cytoskeleton architecture and actomyosin activation through the novel protein scaffold function of the unique tail domain and the classical MLCK catalytic function of the kinase domain.
AB - Recently discovered 210-kDa myosin light chain kinase (MLCK-210) is identical to 108-130 kDa MLCK, the principal regulator of the myosin II molecular motor, except for the presence of a unique amino terminal extension. Our in vitro experiments and transfected cell studies demonstrate that the N-terminal half of MLCK-210 unique tail domain has novel microfilament and microtubule binding activity. Consistent with this activity, the MLCK-210 domain codistributes with microfilaments and microtubules in cultured cells and with soluble tubulin in nocodazole-treated cells. This domain is capable of aggregating tubulin dimers in vitro, causing bundling and branching of microtubules induced by taxol. The N-terminal actin-binding region of MLCK-210 has lower affinity to actin (Kd = 7.4 μM) than its central D(F/V)RXXL repeat-based actin-binding site and does not protect stress fibers from disassembly triggered by MLCK inhibition in transfected cells. Obtained results suggest that while being resident on microfilaments, MLCK-210 may interact with other cytoskeletal components through its N-terminal domain. Based on available evidence, we propose a model in which MLCK-210 could organize cell motility by simultaneous control of cytoskeleton architecture and actomyosin activation through the novel protein scaffold function of the unique tail domain and the classical MLCK catalytic function of the kinase domain.
KW - Cytoskeleton
KW - DMSO
KW - EGTA
KW - High molecular weight myosin light chain kinase
KW - Microfilaments
KW - Microtubules
KW - Recombinant fusion proteins
KW - Stress fiber stabilization
KW - Transfection
KW - dimethyl sulfoxide
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U2 - 10.1016/j.yexcr.2004.04.025
DO - 10.1016/j.yexcr.2004.04.025
M3 - Article
C2 - 15265689
AN - SCOPUS:3242677829
VL - 298
SP - 407
EP - 417
JO - Experimental Cell Research
JF - Experimental Cell Research
SN - 0014-4827
IS - 2
ER -