Differential O-glycosylation in cortical and medullary thymocytes
Por:
Alvarez G., Lascurain R., Hernández-Cruz P., Tetaert D., Degand P., Gorocica P., Espinosa B., Zenteno E., Chávez R.
Publicada:
1 ene 2006
Resumen:
Differentiation of T lymphocytes is characterized by variable expression of CD8/CD4 co-receptor molecules and changes in the glycosylation pattern. In this work, O-glycosylation was analyzed in microsomes from murine thymocytes purified with the PNA and Amaranthus leucocarpus (ALL) lectins, specific for the T antigen (Gal?1,3GalNAc1,0 Ser/Thr) in cortical and medullary thymocytes, respectively. Three peptides were used as acceptors for UDP-N-acetylgalactosamine: polypeptide N-acetylgalactosaminyl-transferase (GalNAc transferase); the peptide motif TTSAPTTS was the best glycosylated one. Cortical ALL-PNA+ thymocytes showed two-fold higher GalNAc transferase activity than ALL+PNA- thymocytes; however, capillary electrophoresis showed a higher proportion of di- versus mono-glycosylated peptides for ALL+PNA- than for ALL-PNA+. We compared the GalNAc transferase activity of thymocytes from dexamethasone-treated mice versus control mice. GalNAc transferase activity was six-fold higher in thymocytes from control mice than from dexamethasone-treated mice; the rate of di-glycosylated peptides for dexamethosone-resistant ALL+ was two-fold higher than for ALL- thymocytes. Our results confirm an upregulated biosynthesis of O-glycosidically linked glycans on T cell surface glycoproteins, and suggest that the modification of GalNAc transferase activity plays a relevant role during the maturation process of thymic cells. © 2006 Elsevier B.V. All rights reserved.
Filiaciones:
Alvarez G.:
Laboratorio de Inmunología, Departamento de Bioquímica, Facultad de Medicina, P.O. Box 70159, 04510, Mexico
Lascurain R.:
Departamento de Bioquímica, Instituto Nacional de Enfermedades Respiratorias, Sector Salud, 14080, Mexico
Hernández-Cruz P.:
Centro de Investigaciones Médicas-Biológicas, Facultad de Medicina, Universidad Autónoma del Estado de Oaxaca, 68020 Oaxaca, Mexico
Tetaert D.:
Institut National de la Santé et la Recherche Médicale U 560, 59045 Lille, France
Degand P.:
Institut National de la Santé et la Recherche Médicale U 560, 59045 Lille, France
Gorocica P.:
Departamento de Bioquímica, Instituto Nacional de Enfermedades Respiratorias, Sector Salud, 14080, Mexico
Espinosa B.:
Departamento de Bioquímica, Instituto Nacional de Enfermedades Respiratorias, Sector Salud, 14080, Mexico
Zenteno E.:
Laboratorio de Inmunología, Departamento de Bioquímica, Facultad de Medicina, P.O. Box 70159, 04510, Mexico
Chávez R.:
Laboratorio de Inmunología, Departamento de Bioquímica, Facultad de Medicina, P.O. Box 70159, 04510, Mexico
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