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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
32
pubmed:dateCreated
2003-8-4
pubmed:abstractText
The p21-activated kinase (PAK) homolog, Shk1, is a critical component of a multifunctional Ras/Cdc42/PAK complex required for viability, polarized growth and cell shape, and sexual differentiation in the fission yeast, Schizosaccharomyces pombe. Substrate targets of the Shk1 kinase have not previously been described. Here we show that the S. pombe cell polarity factor, Tea1, is directly phosphorylated by Shk1 in vitro. We demonstrate further that Tea1 is phosphorylated in S. pombe cells and that its level of phosphorylation is significantly reduced in cells defective in Shk1 function. Consistent with a role for Tea1 as a potential downstream effector of Shk1, we show that a tea1 null mutation rescues the Shk1 hyperactivity-induced lethal phenotype caused by loss of function of the essential Shk1 inhibitor, Skb15. All phenotypes associated with Skb15 loss, including defects in actin cytoskeletal organization, chromosome segregation, and cytokinesis, are suppressed by tea1 Delta, suggesting that Tea1 is a potential mediator of multiple Shk1 functions. S. pombe cells carrying a weak hypomorphic allele of shk1 together with a tea1 Delta mutation exhibit a cytokinesis defective phenotype that is significantly more severe than that observed in the respective single mutants, providing evidence that Shk1 and Tea1 cooperate to regulate cytokinesis. In addition, we show that S. pombe cells carrying the orb2-34 allele of shk1 exhibit a pattern of monopolar growth similar to that observed in tea1 Delta cells, suggesting that Shk1 and Tea1 may regulate one or more common processes involved in the regulation of polarized cell growth. Taken together, our results strongly implicate Tea1 as a potential substrate-effector of the Shk1 kinase.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
8
pubmed:volume
278
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
30074-82
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed-meshheading:12764130-Actins, pubmed-meshheading:12764130-Alleles, pubmed-meshheading:12764130-Cell Division, pubmed-meshheading:12764130-Cell Wall, pubmed-meshheading:12764130-Cytoskeleton, pubmed-meshheading:12764130-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:12764130-Glutathione Transferase, pubmed-meshheading:12764130-Microtubule-Associated Proteins, pubmed-meshheading:12764130-Mitosis, pubmed-meshheading:12764130-Models, Biological, pubmed-meshheading:12764130-Mutation, pubmed-meshheading:12764130-Phenotype, pubmed-meshheading:12764130-Phosphorylation, pubmed-meshheading:12764130-Plasmids, pubmed-meshheading:12764130-Precipitin Tests, pubmed-meshheading:12764130-Protein-Serine-Threonine Kinases, pubmed-meshheading:12764130-Schizosaccharomyces, pubmed-meshheading:12764130-Schizosaccharomyces pombe Proteins, pubmed-meshheading:12764130-Time Factors, pubmed-meshheading:12764130-p21-Activated Kinases
pubmed:year
2003
pubmed:articleTitle
The kelch repeat protein, Tea1, is a potential substrate target of the p21-activated kinase, Shk1, in the fission yeast, Schizosaccharomyces pombe.
pubmed:affiliation
Department of Molecular Genetics and Program in Genes and Development, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't