title: Tight binding between a pool of the heterodimeric alpha/beta tubulin and a protein kinase CK2 in Trypanosoma cruzi epimastigotes.
abstract: Tubulin is the predominant phosphoprotein in Trypanosoma cruzi epimastigotes and is phosphorylated by a protein kinase CK2. Interestingly, the presence or absence of divalent cations affected the solubilization of a pool of the parasite tubulin and the CK2 responsible for its phosphorylation. This fraction of tubulin and its kinase co-eluted using phosphocellulose, DEAE-Sepharose and Sephacryl S-300 chromatographies. Anti-alpha tubulin antibodies co-immunoprecipitated both tubulin and the CK2 responsible for its phosphorylation, and anti-CK2 alpha-subunit antibodies immunoprecipitated radioactively labelled alpha and beta tubulin from phosphorylated epimastigote homogenates. Additionally, native polyacrylamide gel electrophoresis of the purified and radioactively labelled fraction containing tubulin and its kinase demonstrated the phosphorylation of a unique band that reacted with both anti-CK2 alpha-subunit and anti-tubulin antibodies. Together, these results establish a strong interaction between a pool of the heterodimeric alpha/beta tubulin and a CK2 in this parasite. Hydrodynamic measurements indicated that the T. cruzi tubulin-CK2 complex is globular with an estimated size of 145.4-147.5 kDa.
authors.affiliation: Departamento de Biología Celular, Universidad Simón Bolívar, Apartado 89.000, Valle de Sartenejas, Caracas 1081-A, Venezuela.
authors.forename: A R
authors.initials: AR
authors.lastname: De Lima
authors.forename: R
authors.initials: R
authors.lastname: Medina
authors.forename: G L
authors.initials: GL
authors.lastname: Uzcanga
authors.forename: K
authors.initials: K
authors.lastname: Noris Suárez
authors.forename: V T
authors.initials: VT
authors.lastname: Contreras
authors.forename: M C
authors.initials: MC
authors.lastname: Navarro
authors.forename: R
authors.initials: R
authors.lastname: Arteaga
authors.forename: J
authors.initials: J
authors.lastname: Bubis
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000276:immunology; D015153:Blotting, Western / Q000379:methods; D047390:Casein Kinase II / Q000378:metabolism*; D047388:Casein Kinases / Q000378:metabolism; D002413:Cations, Divalent / Q000378:metabolism / Q000494:pharmacology; D002478:Cells, Cultured; D002845:Chromatography / Q000379:methods; D047468:Immunoprecipitation / Q000379:methods; D010766:Phosphorylation; D011485:Protein Binding / Q000502:physiology; D011817:Rabbits; D014349:Trypanosoma cruzi / Q000378:metabolism*; D014404:Tubulin / Q000187:drug effects / Q000276:immunology / Q000378:metabolism*
chemical_list: D000913:Antibodies, Protozoan; D002413:Cations, Divalent; D014404:Tubulin; D047390:Casein Kinase II; D047388:Casein Kinases