Neurochemical Research

, Volume 35, Issue 12, pp 2161–2167

Defective GM3 Synthesis in Cog2 Null Mutant CHO Cells Associates to Mislocalization of Lactosylceramide Sialyltransferase in the Golgi Complex

Authors

  • Waldo Spessott
    • Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC (UNC-CONICET), Departamento de Química Biológica, Facultad de Ciencias QuímicasUniversidad Nacional de Córdoba
  • Andrea Uliana
    • Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC (UNC-CONICET), Departamento de Química Biológica, Facultad de Ciencias QuímicasUniversidad Nacional de Córdoba
    • Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC (UNC-CONICET), Departamento de Química Biológica, Facultad de Ciencias QuímicasUniversidad Nacional de Córdoba
ORIGINAL PAPER

DOI: 10.1007/s11064-010-0319-8

Cite this article as:
Spessott, W., Uliana, A. & Maccioni, H.J.F. Neurochem Res (2010) 35: 2161. doi:10.1007/s11064-010-0319-8

Abstract

The conserved oligomeric Golgi (COG) complex is a eight subunit (COG1 to 8) tethering complex involved in the retrograde trafficking of multiple Golgi processing proteins. Here we studied the glycolipid synthesis status in ldlC cells, a Cog2 null mutant CHO cell line. Biochemical studies revealed a block in the coupling between LacCer and GM3 synthesis, resulting in decreased levels of GM3 in these cells. Uncoupling was not attributable to decreased activity of the glycosyltransferase that uses LacCer as acceptor substrate (SialT1). Rather, immunocytochemical experiments evidenced a mislocalization of SialT1 as consequence of the lack of Cog2 in these cells. Co-immunoprecipitation experiments disclose a Cog2 mediated interaction of SialT1 with the COG complex member Cog1. Results indicate that cycling of some Golgi glycolipid glycosyltransferases depends on the participation of the COG complex and that deficiencies in COG complex subunits, by altering their traffic and localization, affect glycolipid composition.

Keywords

GolgiCOG complexGlycosiltransferasesGlycolipids-Sialyltransferase

Copyright information

© Springer Science+Business Media, LLC 2010