Analysis of the functional notation and distinguishing genics expression of the protein family WD of Trypanosoma cruzi.

by Passos, Tatiana dos

Abstract (Summary)
The WD proteins domain containing represents one of the most common functional groups of proteins Trypanosoma cruzi. This domain, usually found as repeats, is a short ~40 aminoacids motif, often terminating in a Trp-Asp (WD) dipeptide. These repeats are thought to form a circularized beta-propeller structures. The WD proteins are a large family found in all eukaryotes and are implicated in a variety of functions ranging from signal transduction and transcription regulation to cell cycle control and apoptosis. The objective of the present work was to identify, to describe and to characterize WD proteins in T. cruzi, as well as evaluate expression profile from microarray data and proteomics. In T. cruzi, were predicted 211 distinct genes containing WD domains. After a redundancy elimination step, were very common in the current state of theassembly of the genome of this parasite, 117 sequences minimally different were defined, named supra-genes. The great majority of these supra-genes (81.2%) do not present a functional notation, being characterized as hypothetical proteins. The remaining genes contaim a functionalnotation as cytoskeleton association, vesicle trafficking and signaling. A description of the bioinformatics characteristics for similarity of protein sequences, as well as the revision ofpertinent literature, was carried for these 117 proteins. The great majority of described WD proteins in eukaryotes are found in T. cruzi, T. brucei and Leishmania major; organismsphylogenetically related and collectively named TriTryps. Only tree supra-genes were found only in T. cruzi. The great majority of WD proteins (88%) does not present identified accessory modules. After analysis of similarity carried for 117 genes WD, 37 hypothetical proteins (38.9% of the 95 genes without functional notation) were written down with a probable cellular function. The main cellular processes are: biogenesis of ribosome, flagellum and splicing of mRNA. Microarray results related to the process of metacyclogenesis and life cycle of T. cruzi (PROBST et al., in preparation) and proteomics results related to life cycle forms (ATWOOD et al., 2005) were analyzed. A total of 44 WD genes (37.60%) through microarray analysis revealed modulated during the process of differentiation and peptides were identified for 9 WD proteins, reinforcing the functional importance of this family. A 60 mer oligonucleotide practically coring all the genes T. cruzi of WD family, was developed in this work. A total of 41 genes (29.92%) with diferential expression were identified. The cloning of these genes was initiated aiming a posterior molecularand functional characterization.
This document abstract is also available in Portuguese.
Bibliographical Information:

Advisor:Christian Macagnan Probst; Marco Aurélio Krieger

School:Faculdades Oswaldo Cruz

School Location:Brazil

Source Type:Master's Thesis

Keywords:Trypanosoma cruzi Tryptophan Proteins Gene Expression Aspartic Acid


Date of Publication:12/01/2006

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