Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
17
|
pubmed:dateCreated |
1990-7-16
|
pubmed:abstractText |
Myosin II from Acanthamoeba castellanii is a conventional myosin composed of two heavy chains and two pairs of light chains. The amino-terminal approximately 90 kDa of each heavy chain form a globular head that contains the ATPase site and an ATP-sensitive actin-binding site. The carboxyl-terminal approximately 80 kDa of both heavy chains interact to form a coiled coil, helical rod (through which the molecules self-associate into bipolar filaments) ending in a short nonhelical tailpiece. Phosphorylation of 3 serine residues at the tip of the tail (at positions 11, 16, and 21 from the carboxyl terminus) inactivates the actin-activated Mg2(+)-ATPase activity of myosin II filaments. Previous work had indicated that the activity of each myosin II molecule in a filament reflects the global state of phosphorylation of the filament rather than the phosphorylation state of the molecule itself. We have now purified the approximately 28-kDa carboxyl-terminal region of the heavy chain lacking the last two phosphorylation sites, and we have shown that this peptide copolymerizes with and regulates the actin-activated Mg2(+)-ATPase activities of native dephosphorylated and phosphorylated myosin II. It can be concluded from these studies that the biologically relevant enzymatic activity of myosin II is regulated by a phosphorylation-dependent conformational change in the myosin filaments.
|
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Actins,
http://linkedlifedata.com/resource/pubmed/chemical/Ca(2 ) Mg(2 )-ATPase,
http://linkedlifedata.com/resource/pubmed/chemical/Macromolecular Substances,
http://linkedlifedata.com/resource/pubmed/chemical/Myosin Subfragments,
http://linkedlifedata.com/resource/pubmed/chemical/Myosins
|
pubmed:status |
MEDLINE
|
pubmed:month |
Jun
|
pubmed:issn |
0021-9258
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:day |
15
|
pubmed:volume |
265
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
9993-8
|
pubmed:dateRevised |
2009-11-19
|
pubmed:meshHeading |
pubmed-meshheading:2141027-Acanthamoeba,
pubmed-meshheading:2141027-Actins,
pubmed-meshheading:2141027-Animals,
pubmed-meshheading:2141027-Ca(2+) Mg(2+)-ATPase,
pubmed-meshheading:2141027-Electrophoresis, Polyacrylamide Gel,
pubmed-meshheading:2141027-Enzyme Activation,
pubmed-meshheading:2141027-Kinetics,
pubmed-meshheading:2141027-Macromolecular Substances,
pubmed-meshheading:2141027-Microscopy, Electron,
pubmed-meshheading:2141027-Models, Structural,
pubmed-meshheading:2141027-Molecular Weight,
pubmed-meshheading:2141027-Myosin Subfragments,
pubmed-meshheading:2141027-Myosins,
pubmed-meshheading:2141027-Phosphorylation
|
pubmed:year |
1990
|
pubmed:articleTitle |
Regulation of the actin-activated ATPase activity of Acanthamoeba myosin II by copolymerization with phosphorylated and dephosphorylated peptides derived from the carboxyl-terminal end of the heavy chain.
|
pubmed:affiliation |
Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892.
|
pubmed:publicationType |
Journal Article
|