Functional characterization and protein-protein interactions of trypanosome splicing factors U2AF35, U2AF65 and SF1.
Mol Biochem Parasitol
; 164(2): 137-46, 2009 Apr.
Article
en En
| MEDLINE
| ID: mdl-19320097
ABSTRACT
Early in the assembly of eukaryotes the branch-point binding protein (BBP, also called SF1) recognizes the branch point sequence, whereas the heterodimer U2AF, consisting of a 65 and a 35 kDa subunit, contacts the polypyrimidine tract and the AG splice site, respectively. Herein, we identified, cloned and expressed the Trypanosoma cruzi and Trypanosoma brucei U2AF35, U2AF65 and SF1. Trypanosomatid U2AF65 strongly diverged from yeast and human homologues. On the contrary, trypanosomatid SF1 was conserved but lacked the C-terminal sequence present in the mammalian protein. Yeast two hybrid approaches were used to assess their interactions. The interaction between U2AF35 and U2AF65 was very weak or not detectable. However, as in other eukaryotes, the interaction between U2AF65 and SF1 was strong. At the cellular level, these results were confirmed by fractionation and affinity-selection experiments in which SF1 and U2AF65 were affinity-selected with TAP tagged SF1, but not with TAP tagged U2AF35. Silencing one of the three factors affected growth and trans-splicing in the first step of this reaction. Trypanosomes are the first described example of eukaryotic cells in which the interaction of two expressed U2AF factors seemed to be very weak, or not detectable.
Buscar en Google
Bases de datos:
MEDLINE
Asunto principal:
Trypanosoma brucei brucei
/
Trypanosoma cruzi
/
Proteínas Protozoarias
/
Empalme del ARN
/
Proteínas de Unión al ARN
/
Mapeo de Interacción de Proteínas
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Mol Biochem Parasitol
Año:
2009
Tipo del documento:
Article
País de afiliación:
Argentina