title: Cloning and expression analysis of two novel paraflagellar rod domain genes found in Trypanosoma cruzi.
abstract: The eukaryotic flagellum is one of the most complex macromolecular structures found in cells, containing more than 250 proteins. One unique structure in the flagella of trypanomastids is the paraflagellar rod (PFR). The PFR constitutes a lattice of cytoskeletal filaments that lies alongside the axoneme in the flagella. This unique and complex structure is critical for cell motility, though little is known about its molecular assembly or its role in the lifecycle of trypanosomatids. These proteins are of particular importance in Trypanosoma cruzi, as purified or recombinant PFR proteins have been demonstrated to be immunogenic, protecting mice from a lethal challenge with the parasite. We have searched the T. cruzi databases and discovered two novel genes containing PFR domains. Both these genes are transcribed in vivo and are significantly larger than the previously described PFR genes identified in T. cruzi (>2 Kb). Real-time PCR was used to examine the relative expression levels of six PFR genes, including the two we describe here, in all three stages of T. cruzi's lifecycle. Database searches have further provided EST and genomic sequence support for the presence of these genes in two other pathogenic trypanosomatids, Trypanosoma brucei and Leishmania spp. One of these genes, designated PFR5 contains a carboxy terminal SH3 domain not previously seen in PFR family genes. We propose that this proline-binding SH3 domain may play an important role in the assembly of the PFR.
authors.affiliation: Department of Biological Sciences, Oakland University, Rochester, MI 48309-4401, USA.
authors.forename: April K
authors.initials: AK
authors.lastname: Clark
authors.forename: Gennadiy
authors.initials: G
authors.lastname: Kovtunovych
authors.forename: Sachin
authors.initials: S
authors.lastname: Kandlikar
authors.forename: Shailesh
authors.initials: S
authors.lastname: Lal
authors.forename: Gabrielle A
authors.initials: GA
authors.lastname: Stryker
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015870:Gene Expression; D017125:Genes, Protozoan; D008969:Molecular Sequence Data; D010802:Phylogeny; D017434:Protein Structure, Tertiary / Q000235:genetics; D015800:Protozoan Proteins / Q000235:genetics*; D016415:Sequence Alignment; D017385:Sequence Homology; D014349:Trypanosoma cruzi / Q000235:genetics*
chemical_list: D015800:Protozoan Proteins; C045519:paraflagellar rod proteins, Trypanosoma brucei