Structural and Biological Analysis of Retromer Complex in the protozoan parasite Giardia lamblia

MIRAS S.L; RIVERO M.R; ROPOLO A.S; TOUZ M.C

Montevideo

Conferencia; First Latin America Regional Conference of the Society for Computational Biology; 2010

Giardia lamblia is a primitive unicellular eukaryotic microorganism that passes through two stages or phases in their biological life cycle: the trophozoite, a vegetative replication of the parasite, and the cyst, the infective form. This cell has organelles characteristic eukaryotic organisms, as two nuclei, endoplasmic reticulum (ER: endoplasmic reticulum) and peripheral vacuoles (PVs: Peripheral vacuoles) with hydrolytic activity that would meet simultaneously functions endosomes and lysosomes. Even without a typical Golgi apparatus, transport, distribution and protein secretion occur normally. The retrómero is a multimeric complex associated with the cytosolic face of endosomes and mediates the retrograde transport of transmembrane proteins from endosomes to the trans-Golgi (TGN). The same is constituted by the protein subcomplex Vps (vacuolar protein sorting) and the subcomplex proteins belonging to the family of Sorting nexin (SNX). This has a central role in the transport of transmembrane receptors via a tubulovesicular structure. By searching the GiardiaDB, we found genes that codified to the subcomplex gVps35, gVps29, and gVps26 but not SNX1 or SNX2. Analysis of the sequence and structure of these proteins showed similarities with the ones described in yeast and mammalian cells (Fig.1A  and 1B)