Identification of SUMO targets in Trypanosoma brucei by proteomic analysis

IRIBARREN P; BAYONA, J.; CARMONA SJ; ARIGI E; AGÜERO F; JOSÉ CAZZULO, JUAN; ALMEIDA I; ALVAREZ, V. E.

Mendoza

Congreso; XLVIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

SUMOylation is a conserved post translational modification that involves the covalent attachment of a small ubiquitin-like protein called SUMO to a variety of proteins participating in diverse cellular processes including transcriptional control, nuclear transport, DNA repair and signal transduction. The functional consequences of SUMO attachment depend on each particular substrate but are based on the alteration of the target interaction surface, leading mainly to changes in its activity or subcellular localization. Previous studies performed by our group and others have shown the importance of SUMO in the biology of trypanosomatids as can be inferred from a global proteomic map of SUMOylated proteins in T. cruzi and as it was demonstrated by the essentiality of the system in T. brucei procyclic (PC) and bloodstream (BS) forms. The aim of this work is to improve the proteomic identification of SUMO targets in T. brucei by performing SUMO chromosomal tagging. This strategy enables SUMO expression at physiological levels, avoids the competition with the endogenous form, while providing tags for tandem affinity purification of SUMO and SUMO conjugates. We have successfully purified SUMOylated proteins from PC and BS hemizygote clones, and obtained their proteomic profile. We are currently validating these results in vivo for the top 20 targets.