title: Identification and characterization of Theileria annulata heat-shock protein 90 (HSP90) isoforms.
abstract: Heat-shock proteins (HSPs) refer to a group of proteins whose synthesis is enhanced upon sudden increase in temperature or exposure to a variety of other stressors. In this study, Theileria annulata (T. annulata) HSP90 was identified and characterized as a first step to understand the function of this molecule in T. annulata-infected cells. Our results indicated the existence in the genome of T. annulata of two HSP90 genes: one located in chromosome one (TaHSP90-Chr1) and the other in chromosome four (TaHSP90-Chr4). The amino acid alignment between the two isoforms has shown identity and similarity values of 23.52% and 30.26%, respectively. Theileria annulata recombinant HSP90 proteins were expressed using a bacterial expression system and could be recognized in Western blots by rabbit anti-serum raised against an antigenic peptide derived from a unique sequence of TaHSP90-Chr1. On the other hand, bovine HSP90 was detected in T. annulata-infected cells using Western blot and immunocytostaining. To demonstrate the effect of the inhibition of HSP90 on the survival of T. annulata-infected cells, Geldanamycin (GA), a specific inhibitor for HSP90, was used. Upon GA treatment, p53 was observed to translocate into the host cell nucleus, a phenomenon that occurs in cells undergoing apoptosis. Using flowcytometry, a significant increase (P = 0.028) in cell death (%) was observed in T. annulata-infected cells treated with two different GA concentrations, 0.5 and 1 μm, and incubated for 24, 48 and 72 h.
authors.affiliation: Division of Veterinary Infection-Biology and -Immunology, Department of Infection, Research Center Borstel, Borstel, Schleswig-Holstein, Germany.
authors.forename: S B
authors.initials: SB
authors.lastname: Mohammed
authors.forename: M A
authors.initials: MA
authors.lastname: Bakheit
authors.forename: M
authors.initials: M
authors.lastname: Ernst
authors.forename: J S
authors.initials: JS
authors.lastname: Ahmed
authors.forename: U
authors.initials: U
authors.lastname: Seitzer
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D002460:Cell Line / Q000469:parasitology; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D018841:HSP90 Heat-Shock Proteins / Q000096:biosynthesis / Q000235:genetics*; D016133:Polymerase Chain Reaction; D020033:Protein Isoforms; D016053:RNA, Protozoan / Q000032:analysis / Q000235:genetics*; D016796:Theileria annulata / Q000235:genetics / Q000378:metabolism*; D013801:Theileriasis / Q000469:parasitology* / Q000473:pathology
chemical_list: D018841:HSP90 Heat-Shock Proteins; D020033:Protein Isoforms; D016053:RNA, Protozoan
keywords: Heat-shock protein 90 (HSP90); P53; Theileria; apoptosis