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dc.contributor.authorNakamura, F.
dc.contributor.authorHuang, L.
dc.contributor.authorPestonjamasp, Kersi N.
dc.contributor.authorLuna, Elizabeth J.
dc.contributor.authorFurthmayr, H.
dc.date2022-08-11T08:11:04.000
dc.date.accessioned2022-08-23T17:31:37Z
dc.date.available2022-08-23T17:31:37Z
dc.date.issued1999-08-06
dc.date.submitted2007-11-28
dc.identifier.citation<p>Mol Biol Cell. 1999 Aug;10(8):2669-85.</p>
dc.identifier.issn1059-1524 (Print)
dc.identifier.doi10.1091/mbc.10.8.2669
dc.identifier.pmid10436021
dc.identifier.urihttp://hdl.handle.net/20.500.14038/50776
dc.description.abstractActivation of human platelets with thrombin transiently increases phosphorylation at (558)threonine of moesin as determined with phosphorylation state-specific antibodies. This specific modification is completely inhibited by the kinase inhibitor staurosporine and maximally promoted by the phosphatase inhibitor calyculin A, making it possible to purify the two forms of moesin to homogeneity. Blot overlay assays with F-actin probes labeled with either [32P]ATP or 125I show that only phosphorylated moesin interacts with F-actin in total platelet lysates, in moesin antibody immunoprecipitates, and when purified. In the absence of detergents, both forms of the isolated protein are aggregated. Phosphorylated, purified moesin co-sediments with alpha- or beta/gamma-actin filaments in cationic, but not in anionic, nonionic, or amphoteric detergents. The interaction affinity is high (Kd, approximately 1.5 nM), and the maximal moesin:actin stoichiometry is 1:1. This interaction is also observed in platelets extracted with cationic but not with nonionic detergents. In 0.1% Triton X-100, F-actin interacts with phosphorylated moesin only in the presence of polyphosphatidylinositides. Thus, both polyphosphatidylinositides and phosphorylation can activate moesin's high-affinity F-actin binding site in vitro. Dual regulation by both mechanisms may be important for proper cellular control of moesin-mediated linkages between the actin cytoskeleton and the plasma membrane.
dc.language.isoen_US
dc.relation<p><a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=10436021&dopt=Abstract">Link to article in PubMed</a></p>
dc.subjectActins
dc.subjectAmino Acid Sequence
dc.subjectBiochemistry
dc.subjectBlood Platelets
dc.subjectCytoskeleton
dc.subjectDetergents
dc.subjectHumans
dc.subjectMicrofilament Proteins
dc.subjectMolecular Sequence Data
dc.subjectPhosphatidylinositol 4,5-Diphosphate
dc.subjectPhosphatidylinositols
dc.subjectPhosphorylation
dc.subjectQuaternary Ammonium Compounds
dc.subjectThreonine
dc.subjectCell Biology
dc.subjectLife Sciences
dc.subjectMedicine and Health Sciences
dc.titleRegulation of F-actin binding to platelet moesin in vitro by both phosphorylation of threonine 558 and polyphosphatidylinositides
dc.typeJournal Article
dc.source.journaltitleMolecular biology of the cell
dc.source.volume10
dc.source.issue8
dc.identifier.legacyfulltexthttps://escholarship.umassmed.edu/cgi/viewcontent.cgi?article=1300&amp;context=wfc_pp&amp;unstamped=1
dc.identifier.legacycoverpagehttps://escholarship.umassmed.edu/wfc_pp/301
dc.identifier.contextkey397391
refterms.dateFOA2022-08-23T17:31:38Z
html.description.abstract<p>Activation of human platelets with thrombin transiently increases phosphorylation at (558)threonine of moesin as determined with phosphorylation state-specific antibodies. This specific modification is completely inhibited by the kinase inhibitor staurosporine and maximally promoted by the phosphatase inhibitor calyculin A, making it possible to purify the two forms of moesin to homogeneity. Blot overlay assays with F-actin probes labeled with either [32P]ATP or 125I show that only phosphorylated moesin interacts with F-actin in total platelet lysates, in moesin antibody immunoprecipitates, and when purified. In the absence of detergents, both forms of the isolated protein are aggregated. Phosphorylated, purified moesin co-sediments with alpha- or beta/gamma-actin filaments in cationic, but not in anionic, nonionic, or amphoteric detergents. The interaction affinity is high (Kd, approximately 1.5 nM), and the maximal moesin:actin stoichiometry is 1:1. This interaction is also observed in platelets extracted with cationic but not with nonionic detergents. In 0.1% Triton X-100, F-actin interacts with phosphorylated moesin only in the presence of polyphosphatidylinositides. Thus, both polyphosphatidylinositides and phosphorylation can activate moesin's high-affinity F-actin binding site in vitro. Dual regulation by both mechanisms may be important for proper cellular control of moesin-mediated linkages between the actin cytoskeleton and the plasma membrane.</p>
dc.identifier.submissionpathwfc_pp/301
dc.contributor.departmentDepartment of Cell Biology
dc.source.pages2669-85


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