Bioinformatioc prediction and characteritation of the SNARE protein family in the divergent protozoan Giardia lamblia

RODRIGO QUIROGA; VANINA ELÍAS; CESAR GERMAN PRUCCA; HUGO DANIEL LUJÁN

Cordoba Argentina

Congreso; XXI Reunion Anual de la Sociedad Argentina de Prodtozoologia; 2007

Sociedad Argentina de Protozoologia

Giardia is an early branching protist with unusual eukaryotic characteristics, including the absence of a morphologically evident Golgi aparatus. Altough both constitutive and regulated pathways for proteins secretion exist in Giardia spp, little is known about the molecules and mechanisms specifically involved in vesicular docking and fusion. In higher eukaryotes, the SNARE proteins play essential roles in these processes through the formation of complexes between proteins present on donor and target membranes. Here, we present results from complete bioinformatic analysis of the Giardia genome for SNARE enconding genes, the validation of this data through Hidden Markov Model construction and evaluation, as well as the prediction of the 3D protein structure through modeling by satisfaction of spacial restraints. The characterization of these proteins in Giardia allowed a more sensitive and effective prediction of this protein family in other eukaryotes who hav completely sequenced genomes but do not have a complete set of SNARE proteins characterized. The description of all these novel SNAREs  in ancient eukaryotes will allow a detailed study of the evolution of this proteins family and more specifically of the SNAP proteins due to the factthat they are present in only some of the aforementioned organisms and it has been proposed that SNAP proteins appeared during eukaryotic evolution by fusion of two SNARE proteins