CHARACTERIZATION OF TRYPANOSOMA CRUZI ALPHA-TUBULIN ACETYLTRANSFERASE (TCATAT)

ALONSO VL; CARLONI ME; SERRA EC; PEZZA A; TAVERNELLI LE

Mar del Plata

Congreso; Reunion Anual de Sociedades de Biociencias SAIC - SAFE - SAB - SAP; 2019

Sociedades de Biociencias

Microtubules are essential cellular structures built from tubulin that show promise as antimicrobial drug targets. The arrangement of trypanosomatid cytoskeleton is simpler than those of other eukaryotic cells but it is precisely organized and constituted by stable microtubules. Such microtubules compose the mitotic spindle, the basal body, the flagellar and the subpellicular microtubules, which are connected to each other and to the plasma membrane forming a helical arrangement along the cell body. Acetylation on K40 of α-tubulin is conserved from lower eukaryotes to mammals and is associated with microtubule stability. It is also known that K40 acetylation occurs significantly on flagella, centrioles, cilia, basal body and the mitotic spindle. The primary acetyltransferase that delivers this modification was recently identified as Mec-17/ATAT, a Gcn5-related N-acetyltransferase. Despite evidence supporting a role for K40 acetylation in microtubule stability, its biological function in vivo is unclear. We have expressed T. cruzi ATAT with an HA tag in epimastigotes using the inducible vector pTcINDEX-GW. Over-expressing parasites present a growth defect and also we observed a diminished infectivity and an alteration in the differentiation from amastigotes to trypomastigotes. TcATAT is located in the cytoskeleton and flagella of T. cruzi as determined by western blot and confocal microscopy. Moreover, TcATAT colocalizes with acetylated alpha-tubulin in these structures and over-expression causes increased levels of the acetylated isoform. Also, over-expression causes a halt in the cell cycle progression of epimastigotes determined by flow cytometry and SEM. Finally, when this ATAT is over-expressed we observed that parasites become more resistant to microtubule depolymerizing drugs. These evidence supports the idea that tubulin acetylation is crucial for T. cruzi replication and differentiation and that TcATAT is responsible for this postranslational modification.