THE EXPRESSION OF BOTH ISOFORMS OF UGGT ARE DIFFERENTIALLY REGULATED IN T47D CELLS BY PROGESTERONE AND IN MAMMARY GLAND DEVELOPMENT DURING MOUSE PREGNANCY.

ACOSTA AG; MIRANDA S; KORDON E; RIAL HAWILA MR; CASTRO OA

Buenos Aires

Congreso; III CONGRESO INTERNACIONAL DE MEDICINA TRASLACIONAL; 2016

Maestría Internacional en Ciencias Biomédicas (IMBS). FFYB

The expression of both isoforms of UGGT are differentially regulated in T47D cells byProgesterone and in mammary gland development during mouse pregnancy.Acosta-Montalvo A.G1,3., Rial Hawila, R2., Kordon E4., Miranda S.E2., Castro O.A1,3.1 IQUIBICEN (CONICET-UBA); 2 ININCA (CONICET-UBA); 3 FBMC/FCEN/UBA; 4 IFIBYNE(CONICET-UBA)UGGT (UDP-Glc::glycoprotein glucosyltransferase), which has the ability to discriminatefolded from misfolded glycoproteins, is the key component of the quality control mechanismof glycoprotein folding that ensures that only properly folded proteins exit the ER. In yeast,fly, parasites and plants an enzymatically active UGGT is encoded by a single gene whereasthere are two homologues coding for UGGT-like proteins (UGGT-1 and UGGT-2) invertebrates and in some species of nematodes. We reported that both isoforms play differentbiological roles in C.elegans. We showed that the uggt-2 null mutant is lethal, while the uggt-1 null mutant is only barely affected. Recently, we showed that both isoforms weredifferentially regulated by high doses of progesterone (P4) in a mouse hybridoma. Previousanalysis of ChIP-seq datasets for PR in human mammary ductal carcinoma cell line T47Drevealed that it binds uggt2 promoter at different concentrations of R5020 (10-8 M and 10-7M). These facts suggest that the level of expression of uggt2 may be regulated by P4 in adose dependent manner. To confirm this hypothesis, we studied the expression of bothisoforms in T47D cells in the presence of increasing doses of P4. We also analyzed the levelexpression of both isoforms of UGGT in vivo using the mouse mammary gland duringpregnancy as a physiological model. We found that the mRNA level expression of uggt1determined by RT-qPCR in the mammary gland increases throughout pregnancy while thatof uggt-2 shows an opposite pattern. Moreover, when we studied the protein patternexpression of UGGT1 and UGGT-2 in cuboid epithelial cells and in adipocytes we found thatthey were differentially regulated. Both isoforms peak in epithelial cells at day 15, while inadipocytes UGGT1 decreases during pregnancy and UGGT-2 levels remains constant. Onthe other hand, the expression of uggt1 in T47D cells culture increases as the P4concentration raises until two fold increase at 10-5 M P4 at 24 h. Instead, the level ofexpression of uggt-2 diminishes up to 40 % at 10-8 and 10-7 M de P4 and we found no changerespect to the control at 10 -5 M. As a summary we can conclude that both enzymes aredifferentially regulated by P4 in T47D cells and their expression in mammary gland showedalso a different expression pattern supporting the idea that each isoform plays a different biological role