Linked Life Data

11448958

Source:http://linkedlifedata.com/resource/pubmed/id/11448958

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
36
pubmed:dateCreated
2001-9-4
pubmed:abstractText
We expressed the small subunit of smooth muscle myosin light chain phosphatase (MPs) in Escherichia coli, and have studied its molecular properties as well as its interaction with the targeting subunit (MPt). MPs (M(r) = 18,500) has an anomalously low electrophoretic mobility, running with an apparent M(r) of approximately 21,000 in sodium dodecyl sulfate-gel electrophoresis. CD spectroscopy shows that it is approximately 45% alpha-helix and undergoes a cooperative temperature-induced unfolding with a transition midpoint of 73 degrees C. Limited proteolysis rapidly degrades MPs to a stable C-terminal fragment (M(r) = 10,000) that retains most of the helical content. Rotary shadowing electron microscopy reveals that it is an elongated protein with two domains. Sedimentation velocity measurements show that recombinant MPt (M(r) = 107,000), intact MPs, and the 10-kDa MPs fragment are all dimeric, and that MPs and MPt form a complex with a molar mass consistent with a 1:1 heterodimer. Sequence analysis predicts that regions in the C-terminal portions of both MPs and MPt have high probabilities for coiled coil formation. A synthetic peptide from a region of MPs encompassing residues 77-116 was found to be 100% alpha-helical, dimeric, and formed a complex with MPt with a molecular mass corresponding to a heterodimer. Based on these results, we propose that MPs is an elongated molecule with an N-terminal head and a C-terminal stalk domain. It dimerizes via a coiled coil interaction in the stalk domain, and interacts with MPt via heterodimeric coiled coil formation. Since other proteins with known regulatory function toward MP also have predicted coiled coil regions, our results suggest that these regulatory proteins target MP via the same coiled coil strand exchange mechanism with MPt.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
276
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
34318-22
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:11448958-Animals, pubmed-meshheading:11448958-Binding Sites, pubmed-meshheading:11448958-Chickens, pubmed-meshheading:11448958-Circular Dichroism, pubmed-meshheading:11448958-DNA, Complementary, pubmed-meshheading:11448958-Dimerization, pubmed-meshheading:11448958-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:11448958-Gene Library, pubmed-meshheading:11448958-Microscopy, Electron, pubmed-meshheading:11448958-Muscle, Smooth, pubmed-meshheading:11448958-Myosin-Light-Chain Phosphatase, pubmed-meshheading:11448958-Phosphoprotein Phosphatases, pubmed-meshheading:11448958-Protein Binding, pubmed-meshheading:11448958-Protein Conformation, pubmed-meshheading:11448958-Protein Isoforms, pubmed-meshheading:11448958-Protein Structure, Secondary, pubmed-meshheading:11448958-Recombinant Proteins, pubmed-meshheading:11448958-Signal Transduction, pubmed-meshheading:11448958-Ultracentrifugation
pubmed:year
2001
pubmed:articleTitle
Recombinant small subunit of smooth muscle myosin light chain phosphatase. Molecular properties and interactions with the targeting subunit.
pubmed:affiliation
Muscle and Motility Group, Boston Biomedical Research Institute, Watertown, Massachusetts 02472, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.