Advances on trypanosomatid TcPIN1 function

ERBEN E.D; ROJAS F; VALGUARNERA E.,; TÉLLEZ-IÑÓN M.T.

Rosario, Argentina

Congreso; XLII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology (SAIB).; 2006

Sociedad Argentina de Investigación en Bioquímica y Biología Moelcular

Studies in multiple systems have suggested that PIN-1 is a protein that plays a critical role for mitosis progression in mammalian cells and yeast. PIN1 participate in the phosphorylation-dependent prolyl isomerase that changes the conformation of its substrates controlling cell-cycle progression. The peptidyl-prolyl cis/trans isomerases (PPIases) are a conserved family of proteins that catalyzes the cis/trans isomerization of proline preceding peptide bonds. This post-phosphorylation isomerization can lead to conformational changes in the substrate proteins and modulate their functions.   In Trypanosoma cruzi we identified TcPIN1 as a homologue of the essential hPin1 parvulin PPIase. Based on functional assays, subcellular localization and preliminary enzymatic PPIase activity, we showed that TcPIN1 is a member of the Pin1-type PPIases, suggesting the existence of an additional conserved level of post-translational control in trypanosomatids. To gain a broader understanding of how TcPIN1 is regulated and explain to its role in trypanosomatids cell biology, a two-hybrid screen was performed using TcPIN1 as bait. Several different open reading frames were identified that codify for putative interacting proteins. Although the outcome of a screening often results in many new hypotheses, they still need to be validated by other techniques. The determination of the actual function of these novel candidates will be discussed. Supported by FONCYT, CONICET, UBA.