Identification, Molecular and Functional Characterization of Calmodulin Gene of Phytomonas serpens 15T that Shares High Similarity with its Pathogenic Counterparts Trypanosoma cruzi

Abstract

In trypanosomatids, Ca²+-binding proteins can affect parasite growth, differentiation and invasion. Due to their importance for parasite maintenance, they become an attractive target for drug discovery and design. Phytomonas serpens 15T is a non-human pathogenic trypanosomatid that expresses important protein homologs of human pathogenic trypanosomatids. In this study, the coding sequence of calmodulin, a Ca²+-binding protein, of P. serpens 15T was cloned and characterized. The encoded polypeptide (CaMP) displayed high amino acid identity to homolog protein of Trypanosoma cruzi and four helix-loop-helix motifs were found. CaMP sequence analysis showed 20 amino acid substitutions compared to its mammalian counterparts. This gene is located on a chromosomal band with estimated size of 1,300 kb and two transcripts were detected by Northern blot analysis. A polyclonal antiserum raised against the recombinant protein recognized a polypeptide with an estimated size of 17 kDa in log-phase promastigote extracts. The recombinant CaMP retains its Ca²+-binding capacity.

Oral Exposure to Phytomonas serpens Attenuates Thrombocytopenia and Leukopenia during Acute Infection with Trypanosoma cruzi

“…The results showing that hyperimmune sera against P. serpens attenuated the effect of TS on platelets led us to ask whether this inhibition was due to the presence of specific antibodies directed against the enzymatic domain of TS since P. serpens shares common antigens with T. cruzi [26], [45]. However, the serum from mice immunized with P. serpens do not recognize TS when tested by Western blot or ELISA.…”