Authors: Mariana L Ferrari Guillermo A Gomez Hugo J F Maccioni
Publish Date: 2012/03/03
Volume: 37, Issue: 6, Pages: 1325-1334
Abstract
The functional link between glycolipid glycosyltransferases GT relies on the ability of these proteins to form organized molecular complexes The organization stoichiometry and composition of these complexes may impact their sorting properties subGolgi localization and may determine relative efficiency of GT in different glycolipid biosynthetic pathways In this work by using Förster resonance energy transfer microscopy in live CHOK1 cells we investigated homo and heterocomplex formation by different GT as well as their spatial organization and molecular stoichiometry on Golgi membranes We find that GalNAcT and GalT2 Ntd are able to form heterocomplexes in a 12 molar ratio at the transGolgi network and that GalT2 but not GalNAcT forms homocomplexes Also GalNAcT/GalT2 complexes exhibit a stable behavior reflected by its clustered lateral organization These results reveals that particular topological organization of GTs may have functional implications in determining the composition of glycolipids in cellular membranesThis work was supported in part by Grants from Agencia Nacional de Promoción Científica y Tecnológica PICT·200601239 Universidad Nacional de Córdoba y MinCyT Córdoba We thank the technical assistance of G Schachner and S Deza with cell cultures and of C Mas and M C Sampedro with confocal microscopy MLF and GAG were recipients of CONICET Fellowships and HJFM is Career Investigator of CONICET Argentina
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