TcADKn an adenylate kinase of T. cruzi involved in ribosome biogenesis

CAMARA, MARIA DE LOS MILAGROS; BOUVIER, LEON; MIRANDA, MARIANA; PEREIRA, CA

Mar del Plata

Congreso; IX Congreso Argentino de Protozoología y Enfermedades Parasitarias (SAP); 2011

Adenylate kinases (ADKs) are enzymes involved in cellular energetic homeostasis; they are involved in nucleotide interconversion. In typical eukaryoticcells, there are very few isoforms of ADKs however, in trypanosomatids there have been characterized a large number of isoforms. Nuclear ADKshave been recently characterized in several organisms; in yeast it has been proved that it is an essential protein involved in the ribosome?s small subunitprocessing. In this work we studied the nuclear ADK isoform (TcADKn) of T. cruzi. We measured the biochemical activity of this enzyme findingthat it presents ADK and ATPase activity being the p-loop essential for both activities. We mapped the non-canonical nuclear localization signal, narrowingit to the amino terminal of the protein. Furthermore we studied the TcADKn localization and expression under different drugs or media treatments,and also along the parasites growth curve: transcription interruption and starvation delocalized TcADKn from the nucleus. Rapamycin treatmentsenhanced its nuclear localization, a typical effect observed for ribosomal proteins dependant on the mTOR pathway. We detected that the3?UTR of TcADKn could be the responsible of the differential expression levels along the growth curve. Finally complementation assays in yeastsrevealed that it could be involved in similar processes as its yeast homolog FAP7.