Development of a SRPK-null model for evaluating SR network components in trypanosomatids.

LOBO, GUILLERMO; FLAWIÁ, MIRTHA M; TORRES, HÉCTOR N.

Rosario- Argentina

Congreso; XLII Reunión Anual de SAIB; 2006

SAIB

SR proteins are the main non-snRNP components of spliceosome and together with their specific kinases constitute the “SR Network”. Several kinases have been reported to phosphorylate RS domain-containing splicing factors, including SRPK’s and Cdc28/Cdc2-like kinase (Clk/Sty). Gene expression is also synchronized with the cell division cycle. Therefore, intricate interplay exists among pre-mRNA splicing, transcription, and cell cycle. SR proteins and SR protein-specific kinases may constitute a protein relay or networks to regulate the coupling of splicing, transcription, and cell cycle in mammalian cells. In trypanosomatids, the SR network is composed by only one SR and its specific kinase protein, TcSR-TcSRPK in <i>T. cruzi</i> and TSR1-TbSRPK in <i>T. brucei</i>. These proteins were functionally characterized in different <i>in vitro</i> and in vivo models, as HeLa cells, yeast and <i>T. brucei</i>. The fission yeast <i>Schizosaccharomyces pombe</i> presents two SRPKs, Dsk1 (SRPK) and Kic1 (Clk/Sty). Yeast <i>dsk1</i>-null <i>kic1</i>-null mutant cells grew extremely slowly and formed microcolonies. The current work presents the development of TbSRPK-deleted cell line. The initial characterization shows differences in growth rate compared to 1913 strain (<i>wild type</i>), suggesting TbSRPK-deleted cell line must be a useful model to study SR Network components in a homologous model.