Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
Pt 15
pubmed:dateCreated
2001-10-30
pubmed:abstractText
In human cells, MAP4, a microtubule-associated protein ubiquitously expressed in proliferating cells, has been shown to undergo in vivo phosphorylation. Two phosphorylation sites, serines 696 and 787, lie within the proline-rich region of its microtubule-binding domain. To test the hypothesis that phosphorylation at these sites influences microtubule properties or cell cycle progression, we prepared stable cell lines that inducibly express versions of MAP4 in which phosphorylation of these two serines was prevented by their replacement with alanine, lysine, or glutamate residues (AA-, KK-, or EE-MAP4). All nonphosphorylatable mutant forms of MAP4 expressed in mouse Ltk- cells were localized to MT arrays that were unremarkable in appearance. Expression of nonphosphorylatable mutants of MAP4 did not affect cell doubling time; however, expression of some mutants altered progression into or through cell division. Interactions of mutant MAP4 with MTs were examined in vitro. KK mutant MAP4 bound MTs more avidly than its wild-type counterpart, WT-MAP4. In vivo MT polymer also differed among the mutants: MTs in cells expressing the KK- and AA-MAP4 forms were more resistant to nocodazole depolymerization than those in cells expressing EE- or WT-MAP4 forms. Our results demonstrate that phosphorylation alters MAP4 properties and suggest a raison d'être for phosphorylation of the MAP4 microtubule-binding domain during cell cycle progression.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9533
pubmed:author
pubmed:issnType
Print
pubmed:volume
114
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2879-87
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:11683421-Amino Acid Sequence, pubmed-meshheading:11683421-Animals, pubmed-meshheading:11683421-Antineoplastic Agents, pubmed-meshheading:11683421-Binding Sites, pubmed-meshheading:11683421-CDC2 Protein Kinase, pubmed-meshheading:11683421-Cell Line, pubmed-meshheading:11683421-Culture Media, Serum-Free, pubmed-meshheading:11683421-Cyclin B, pubmed-meshheading:11683421-Fibroblasts, pubmed-meshheading:11683421-Gene Expression, pubmed-meshheading:11683421-Mice, pubmed-meshheading:11683421-Microtubule-Associated Proteins, pubmed-meshheading:11683421-Microtubules, pubmed-meshheading:11683421-Mitosis, pubmed-meshheading:11683421-Molecular Sequence Data, pubmed-meshheading:11683421-Mutagenesis, Site-Directed, pubmed-meshheading:11683421-Nocodazole, pubmed-meshheading:11683421-Phosphorylation, pubmed-meshheading:11683421-Serine
pubmed:year
2001
pubmed:articleTitle
Phosphorylation of MAP4 affects microtubule properties and cell cycle progression.
pubmed:affiliation
Department of Biological Sciences, College of Arts & Sciences, Columbia University, New York, NY 10027-2450, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.