The Trypanosoma cruzi PIN1 gene encodes a parvulin peptidyl-prolyl cis/trans isomerase able to replace the essential ESS1 in Saccharomyces cerevisiae.

Parvulins are a conserved group of peptidyl-prolyl cis/trans isomerases (PPIases) that catalyze the cis/trans isomerization of proline-preceding peptide bonds. Parvulin-class PPIases are structurally unrelated to cyclophilins and FK506-binding proteins that are defined as receptors for immunosuppressive drugs. In Trypanosoma cruzi we identified parvulin TcPIN1 as a homolog of the human hPin1 PPIase. The 117 amino acids of the TcPIN1 display 40% identity with the catalytic core of hPin1 and exhibit prolyl cis/trans isomerase activity. TcPIN1 lacks the WW domain at the N-terminus, and is able to rescue the temperature-sensitive phenotype on a mutation in the Saccharomyces cerevisiae hPin1 homolog, ESS1/PTF1. Western blot analysis revealed that the enzyme was present both in dividing and non-dividing forms of T. cruzi. In epimastigote cells neither cell growth kinetics nor cell morphology was affected by the overexpression of the small parvulin TcPIN1. These results suggest the occurrence of a supplementary conserved level of post-translational control in trypanosomatids.