title: Cdk5 kinase regulates the association between adaptor protein Bem1 and GEF Cdc24 in the fungus Ustilago maydis.
abstract: Cyclin-dependent kinases from the Cdk5/Pho85 family are thought to play important roles in morphogenesis in species as diverse as yeast and humans. In the phytopathogenic fungus Ustilago maydis Cdk5 has a major role in the maintenance of cell polarity and virulence. This role seems to be related to the ability of the guanine-nucleotide exchange factor (GEF) Cdc24 to localize at the cell tips. However, the elements behind the Cdk5-dependent stabilization of Cdc24 at the cell poles are not well understood. Here we investigate the role of the adaptor protein Bem1 in polarity maintenance in U. maydis. We found that Bem1 and Cdc24 physically interact and colocalize at cell tips and that Cdk5 regulates this interaction. Our data suggest a method by which Cdk5 could regulate polar growth in this phytopathogenic fungus.
authors.affiliation: Departamento de Biotecnología Microbiana, Centro Nacional de Biotecnología-CSIC, 28049 Madrid, Spain. iatabare@cnb.csic.es
authors.forename: Isabel
authors.initials: I
authors.lastname: Alvarez-Tabarés
authors.forename: José
authors.initials: J
authors.lastname: Pérez-Martín
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry / Q000378:metabolism*; D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000378:metabolism; D016764:Cell Polarity; D051360:Cyclin-Dependent Kinase 5 / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D008969:Molecular Sequence Data; D009024:Morphogenesis; D049790:Nuclear Export Signals; D011485:Protein Binding; D021381:Protein Transport; D013347:Subcellular Fractions / Q000378:metabolism; D014588:Ustilago / Q000166:cytology / Q000201:enzymology* / Q000254:growth & development
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D005656:Fungal Proteins; D020662:Guanine Nucleotide Exchange Factors; D049790:Nuclear Export Signals; D051360:Cyclin-Dependent Kinase 5