The C. elegans UDP-Glucose:Glycoprotein Glucosyltransferase Homologues Have Not Identical Function

BUZZI, LUCILA INÉS; SIMONETTA, SERGIO H; PARODI, ARMANDO; CASTRO, OLGA A.

Còrdoba

Otro; Exposición de Posters Curso Microscopá Confocal 2012; 2012

Instituto de Investigación Médica "Mercedes y Martín Ferreyra, Córdoba, Argentina

The UDP-Glc:glycoprotein glucosyltransferase (UGGT) is the key component of the glycoprotein folding quality control mechanism in the endoplasmic reticulum (ER). It behaves as a sensor of glycoprotein conformation as it exclusively glucosylates glycoproteins not displaying their native conformations. Most species have only one gene coding for UGGT-like proteins while Euteleostomi, Caenorhabditis and humans have two homologues. In humans HUGT1 but not HUGT2 displayed UGGT activity and was upregulated under ER stress conditions. Bioinformatics analysis showed that in C.elegans there are two open reading frames F48E3.3 (uggt-1) and F26H9.8 (uggt-2) coding for UGGT homologues. Here we report that C.elegans expresses an active UGGT protein localized in the ER encoded by the uggt-1 gene. We constructed transgenic worms carrying the Puggt-1::gfp construct and found that UGGT-1 is expressed in cells of the nervous system and is upregulated under ER stress. Real time PCR analysis showed that both uggt-1 and uggt-2 are expressed during the entire C. elegans life cycle but at very different levels, being uggt-2 expression at most 3% of uggt-1. Depletion of UGGT-1 by RNAi resulted in a reduced lifespan and that of UGGT-1 and UGGT-2 in a delay in development. With an ER stressor drug the delay was increased. We conclude that UGGT-1 and UGGT-2 play a protective role under ER stress.