title: The beta2-adaptin clathrin adaptor interacts with the mitotic checkpoint kinase BubR1.
abstract: The adaptor AP2 is a heterotetrameric complex that associates with clathrin and regulatory proteins to mediate rapid endocytosis from the plasma membrane. Here, we report the identification of the mitotic checkpoint kinase BubR1 as a novel binding partner of beta2-adaptin, one of the AP2 large subunits. Using two-hybrid experiments and in vitro binding assays, we show that beta2-adaptin binds to BubR1 through its amino-terminal beta2-'trunk' domain, while the beta2-binding region of BubR1 maps to the carboxy-terminal kinase domain. Subcellular immunolocalization studies suggest that the interaction between BubR1 and beta2-adaptin could take place in the cytosol at any time during the cell cycle. In addition, we found that BubR1 and the BubR1-related kinase, Bub1, also bind to beta-adaptins of other AP complexes. Together, these results support a model in which the mitotic checkpoint kinases BubR1 and BuB1, by binding to beta-adaptins, may play novel roles in the regulation of vesicular intracellular traffic.
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale du CNRS-UMR 5089, 205 route de Narbonne, 31077 Toulouse, France. Corinne.Cayrol@ipbs.fr
authors.forename: Corinne
authors.initials: C
authors.lastname: Cayrol
authors.forename: Céline
authors.initials: C
authors.lastname: Cougoule
authors.forename: Michel
authors.initials: M
authors.lastname: Wright
mesh_terms: D033966:Adaptor Protein Complex beta Subunits / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D018797:Cell Cycle Proteins; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008938:Mitosis; D008954:Models, Biological; D010449:Peptide Mapping; D011485:Protein Binding; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases; D017434:Protein Structure, Tertiary; D021122:Protein Subunits; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020798:Two-Hybrid System Techniques
chemical_list: D033966:Adaptor Protein Complex beta Subunits; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D021122:Protein Subunits; D011994:Recombinant Proteins; D011494:Protein Kinases; C584277:BUB1 protein, human; C090464:Bub1 spindle checkpoint protein; D017346:Protein Serine-Threonine Kinases