title: Cap-Gly proteins at microtubule plus ends: is EB1 detyrosination involved?
abstract: Localization of CAP-Gly proteins such as CLIP170 at microtubule+ends results from their dual interaction with α-tubulin and EB1 through their C-terminal amino acids -EEY. Detyrosination (cleavage of the terminal tyrosine) of α-tubulin by tubulin-carboxypeptidase abolishes CLIP170 binding. Can detyrosination affect EB1 and thus regulate the presence of CLIP170 at microtubule+ends as well? We developed specific antibodies to discriminate tyrosinated vs detyrosinated forms of EB1 and detected only tyrosinated EB1 in fibroblasts, astrocytes, and total brain tissue. Over-expressed EB1 was not detyrosinated in cells and chimeric EB1 with the eight C-terminal amino acids of α-tubulin was only barely detyrosinated. Our results indicate that detyrosination regulates CLIPs interaction with α-tubulin, but not with EB1. They highlight the specificity of carboxypeptidase toward tubulin.
authors.affiliation: Institut National de la Santé et de la Recherche Médicale (INSERM) U836, Université Joseph Fourier, Grenoble, France.
authors.forename: Anouk
authors.initials: A
authors.lastname: Bosson
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Soleilhac
authors.forename: Odile
authors.initials: O
authors.lastname: Valiron
authors.forename: Didier
authors.initials: D
authors.lastname: Job
authors.forename: Annie
authors.initials: A
authors.lastname: Andrieux
authors.forename: Marie-Jo
authors.initials: MJ
authors.lastname: Moutin
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D000918:Antibody Specificity / Q000276:immunology; D001921:Brain / Q000378:metabolism; D002417:Cattle; D005347:Fibroblasts / Q000378:metabolism; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000737:chemistry / Q000378:metabolism*; D008870:Microtubules / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D014404:Tubulin / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D000906:Antibodies; C405804:EB1 microtubule binding proteins; D008869:Microtubule-Associated Proteins; D011994:Recombinant Proteins; D014404:Tubulin; D014443:Tyrosine