title: Quantitative phosphoproteomics reveals pathways for coordination of cell growth and division by the conserved fission yeast kinase pom1.
abstract: Complex phosphorylation-dependent signaling networks underlie the coordination of cellular growth and division. In the fission yeast Schizosaccharomyces pombe, the Dual specificity tyrosine-(Y)-phosphorylation regulated kinase (DYRK) family protein kinase Pom1 regulates cell cycle progression through the mitotic inducer Cdr2 and controls cell polarity through unknown targets. Here, we sought to determine the phosphorylation targets of Pom1 kinase activity by SILAC-based phosphoproteomics. We defined a set of high-confidence Pom1 targets that were enriched for cytoskeletal and cell growth functions. Cdr2 was the only cell cycle target of Pom1 kinase activity that we identified in cells. Mutation of Pom1-dependent phosphorylation sites in the C terminus of Cdr2 inhibited mitotic entry but did not impair Cdr2 localization. In addition, we found that Pom1 phosphorylated multiple substrates that function in polarized cell growth, including Tea4, Mod5, Pal1, the Rho GAP Rga7, and the Arf GEF Syt22. Purified Pom1 phosphorylated these cell polarity targets in vitro, confirming that they are direct substrates of Pom1 kinase activity and likely contribute to regulation of polarized growth by Pom1. Our study demonstrates that Pom1 acts in a linear pathway to control cell cycle progression while regulating a complex network of cell growth targets.
authors.affiliation: ‡Department of Biochemistry, ¶Norris Cotton Cancer Center, The Geisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA James.b.moseley@dartmouth.edu Arminja.N.Kettenbach@dartmouth.edu.
authors.forename: Arminja N
authors.initials: AN
authors.lastname: Kettenbach
authors.affiliation: ‡Department of Biochemistry.
authors.forename: Lin
authors.initials: L
authors.lastname: Deng
authors.affiliation: ‡Department of Biochemistry.
authors.forename: Youjun
authors.initials: Y
authors.lastname: Wu
authors.affiliation: ‡Department of Biochemistry.
authors.forename: Suzanne
authors.initials: S
authors.lastname: Baldissard
authors.affiliation: ¶Norris Cotton Cancer Center, The Geisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Adamo
authors.affiliation: ‡Department of Biochemistry, §Department of Genetics, The Geisel School of Medicine at Dartmouth, Hanover, NH 03755, USA; ¶Norris Cotton Cancer Center, The Geisel School of Medicine at Dartmouth, Lebanon, NH 03756, USA.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Gerber
authors.affiliation: ‡Department of Biochemistry, James.b.moseley@dartmouth.edu Arminja.N.Kettenbach@dartmouth.edu.
authors.forename: James B
authors.initials: JB
authors.lastname: Moseley
mesh_terms: D000595:Amino Acid Sequence; D002455:Cell Division / Q000235:genetics; D016764:Cell Polarity; D049109:Cell Proliferation / Q000235:genetics; D002853:Chromatography, Liquid; D015966:Gene Expression Regulation, Fungal; D013058:Mass Spectrometry; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D020543:Proteome / Q000235:genetics* / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics* / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins; C506559:Pal1 protein, S pombe; D010750:Phosphoproteins; D020543:Proteome; D029702:Schizosaccharomyces pombe Proteins; C501888:Tea4 protein, S pombe; C474999:mod5 protein, S pombe; D011494:Protein Kinases; C112212:Pom1 protein, S pombe; C542567:Cdr2 protein, S pombe; D017346:Protein Serine-Threonine Kinases