PROTEIN INTERACTION MAP AND FUNCTIONAL ANALYSIS REVEAL THE UNIQUE ORGANITATION OF THE TRANS-SPLICEOSOMAL E COMPLEX IN TRYPANOSOMES.

ATORRASAGASTI, CATALINA; BERCOVICH, NATALIA; NYAMBEGAH, BENSON; VAZQUEZ, MARTIN; LEVIN, MARIANO J

Iguazú, Misiones

Congreso; Sociedad Argentina de investigación bioquímica y biología molecular; 2004

Data mining of the trypanosome genome data banks (T. cruzi and T. brucei) allowed the identification and cloning of 18 ORFs involved in trans-splicing and 9 polyadenylation factors. Our initial analysis focused on the E complex composed by U2AF, an heterodimer formed by the U2AF 35 and 65 subunits, and the SFI/BBP protein. U2AF35 is a nuclear protein distributed in speckles, and lacking an essential Trp residue in position 134, which is essential for the “tongue in groove” heterodimerization with U2AF65. Accordingly, TcU2AF35 did not interact with the human U2AF65. The trypanosome version of U2AF65 is also largely modified with respect to the human counterpart. The SFI/BBP factor has a modified KH domain and lacks the Zinc finger motifs. A trypanosome specific profile of interactions among these proteins was mapped. Functional analysis showed that “knock down” of U2AF35 affected parasite growth, whereas SFI and U2AF65like did not.