Theileria annulata surface protein (TaSP) is a target of cyclin-dependent kinase 1 phosphorylation in Theileria annulata-infected cells.
Transbound Emerg Dis
; 67 Suppl 1: 40-55, 2020 Mar.
Article
em En
| MEDLINE
| ID: mdl-32174040
ABSTRACT
Leucoproliferative Theileria parasites possess the unique capability to transform their bovine host cell, resulting in tumour-like characteristics like uncontrolled proliferation. The molecular mechanisms underlying this parasite-dependent process are only poorly understood. In the current study, bioinformatic analysis of the Theileria annulata surface protein (TaSP) from different T. annulata isolates identified a conserved CDK1 phosphorylation motif T131 PTK within the extracellular, polymorphic domain of TaSP. Phosphorylation assays with radioactively labelled ATP as well as ELISA-based experiments using a phospho-threonine-proline (pThr-Pro) antibody revealed, that CDK1-cyclin B specifically phosphorylates T131 , identifying TaSP as a substrate in vitro. Confocal microscopy and proximity ligation assays suggest an interaction between CDK1 and TaSP in T. annulata-infected cells. Further studies demonstrated a nearly complete co-localization of the pThr-Pro signal and TaSP only in cells in interphase, pointing towards a cell cycle-dependent event. Immunostainings of isolated, non-permeabilized schizonts confirmed the presence of the pThr-Pro epitope on the schizont's surface. Lambda phosphatase treatment abolished the pThr-Pro signal of the schizont, which was reconstituted by the addition of CDK1-cyclin B. Treatment of T. annulata-infected cells with the CDK1 inhibitor purvalanol A resulted in morphological changes characterized by tubulin-rich cell protrusions and an extension of the schizont, and a dose-dependent reduction of BrdU incorporation and Ki67 staining of T. annulata-infected cells, demonstrating a clear impact on the Theileria-dependent proliferation of the bovine host cell. Our data reveal the parasite surface protein TaSP as a target for the host cell kinase CDK1, a major player during cell division. Targeting the uncontrolled proliferation of Theileria-infected cells is a novel and reasonable approach to limit parasite load in order to facilitate a successful cellular immune response against the parasite.
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Theileriose
/
Doenças dos Bovinos
/
Proteínas de Protozoários
/
Proteína Quinase CDC2
/
Theileria annulata
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Transbound Emerg Dis
Assunto da revista:
MEDICINA VETERINARIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Alemanha