Identification of homologous and orthologous genes of the sap multigenic family in trypanosomes isolated from bats, Trypanosoma Cruzi marinkellei and Trypanosoma Cruzi bat

Abstract

The gene SAP (Serine-, Alanine-, and Proline-rich protein) encodes polypeptidescontaining a high percentage of serine, alanine and proline residues. With the availability ofthe sequences of T. cruzi Genome Projects, we demonstrated that the SAP proteins areencoded by a multigenic family whose members share a conserved central domain and can begrouped into four subfamilies. Some SAP members may be secreted and involved in theprocess of mammalian cell invasion by metacyclic trypomastigotes. SAP binding in the hostcell induces the activation of signal transduction pathways leading to increased intracellularcalcium concentration, an essential event for the internalization of the parasite.Previous work by our group has demonstrated that SAP genes are species-specific andhave similarity to some members of multigenic families, such as mucins and MucinAssociated Surface Protein (MASP). We suggest that SAP evolved from the mucin familyduring the expansion of this family in the process of speciation of the T. cruzi clade.Considering the relevant role of SAP, our objective is to identify and characterizehomologous genes and orthologs of the SAP family in the T. cruzi lineages, including T. cruzibat, and also in the subspecies Trypanosoma cruzi marinkellei. (AU)