Androgen dependence of protein N-glycosylation in rat epididymis
The rat epididymis is known to produce and secrete glycoproteins which interact with spermatozoa during the maturation process. The synthesis of the protein core of these compounds is dependent on androgenic stimulation. As a consequence, we studied the possible androgenic control of the N-glycosyla...
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todo:paper_00137227_v114_n4_p1448_Iusem2023-10-03T14:11:08Z Androgen dependence of protein N-glycosylation in rat epididymis Iusem, N.D. De Larminat, M.A. Tezon, J.G. Blaquier, J.A. Belocopitow, E. glycoprotein testosterone animal cell biological model endocrine system epididymis glycosylation male genital system nonhuman rat Androgen Antagonists Animals Castration Cyproterone Cyproterone Acetate Epididymis Glucosyltransferases Glycoproteins Hexosyltransferases Kinetics Male Mannosyltransferases Microsomes Rats Rats, Inbred Strains Testosterone The rat epididymis is known to produce and secrete glycoproteins which interact with spermatozoa during the maturation process. The synthesis of the protein core of these compounds is dependent on androgenic stimulation. As a consequence, we studied the possible androgenic control of the N-glycosylation process dependent on the dolichol (Dol) pathway. Glucosyl and mannosyl transferase activities in rat epididymal microsomes decreased by approximately 76% after only 2 days of castration with respect to intact controls. Depleted mannosyl transferase activity could be restored to control values by administration of 100 µg/day testosterone propionate (TP) for 4 days. The effect of 20 µg/day TP was blocked by the simultaneous administration of 500 Mg/day of the antiandrogen cyproterone acetate. The addition of excess dolichyl phosphate (12 times the Michaelis-Menten constant (Km) value) to the incubation mixture did not eliminate the difference in mannosyltransferase activity between epididymal microsomes from castrated rats and these from control or testosterone-treated animals. Moreover, the endogenous pool of dolichyl phosphate was found unchanged in the different hormonal situations. Finally, the incorporation of [14C]mannose into lipid-bound oligosaccharides and into glycoproteins was decreased by approximately 60% as a result of castration and reinduced to control values by treatment with TP (50 µg/day for 4 days). The results demonstrate the androgen dependence of the initial steps of N-glycosylation in the rat epididymis and suggest that the hormonal regulation is exerted at the level of Dolnucleotide sugar transferases, rather than upon the size of the endogenous Dol phosphate pool. © 1984 by The Endocrine Society. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_00137227_v114_n4_p1448_Iusem |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
glycoprotein testosterone animal cell biological model endocrine system epididymis glycosylation male genital system nonhuman rat Androgen Antagonists Animals Castration Cyproterone Cyproterone Acetate Epididymis Glucosyltransferases Glycoproteins Hexosyltransferases Kinetics Male Mannosyltransferases Microsomes Rats Rats, Inbred Strains Testosterone |
| spellingShingle |
glycoprotein testosterone animal cell biological model endocrine system epididymis glycosylation male genital system nonhuman rat Androgen Antagonists Animals Castration Cyproterone Cyproterone Acetate Epididymis Glucosyltransferases Glycoproteins Hexosyltransferases Kinetics Male Mannosyltransferases Microsomes Rats Rats, Inbred Strains Testosterone Iusem, N.D. De Larminat, M.A. Tezon, J.G. Blaquier, J.A. Belocopitow, E. Androgen dependence of protein N-glycosylation in rat epididymis |
| topic_facet |
glycoprotein testosterone animal cell biological model endocrine system epididymis glycosylation male genital system nonhuman rat Androgen Antagonists Animals Castration Cyproterone Cyproterone Acetate Epididymis Glucosyltransferases Glycoproteins Hexosyltransferases Kinetics Male Mannosyltransferases Microsomes Rats Rats, Inbred Strains Testosterone |
| description |
The rat epididymis is known to produce and secrete glycoproteins which interact with spermatozoa during the maturation process. The synthesis of the protein core of these compounds is dependent on androgenic stimulation. As a consequence, we studied the possible androgenic control of the N-glycosylation process dependent on the dolichol (Dol) pathway. Glucosyl and mannosyl transferase activities in rat epididymal microsomes decreased by approximately 76% after only 2 days of castration with respect to intact controls. Depleted mannosyl transferase activity could be restored to control values by administration of 100 µg/day testosterone propionate (TP) for 4 days. The effect of 20 µg/day TP was blocked by the simultaneous administration of 500 Mg/day of the antiandrogen cyproterone acetate. The addition of excess dolichyl phosphate (12 times the Michaelis-Menten constant (Km) value) to the incubation mixture did not eliminate the difference in mannosyltransferase activity between epididymal microsomes from castrated rats and these from control or testosterone-treated animals. Moreover, the endogenous pool of dolichyl phosphate was found unchanged in the different hormonal situations. Finally, the incorporation of [14C]mannose into lipid-bound oligosaccharides and into glycoproteins was decreased by approximately 60% as a result of castration and reinduced to control values by treatment with TP (50 µg/day for 4 days). The results demonstrate the androgen dependence of the initial steps of N-glycosylation in the rat epididymis and suggest that the hormonal regulation is exerted at the level of Dolnucleotide sugar transferases, rather than upon the size of the endogenous Dol phosphate pool. © 1984 by The Endocrine Society. |
| format |
JOUR |
| author |
Iusem, N.D. De Larminat, M.A. Tezon, J.G. Blaquier, J.A. Belocopitow, E. |
| author_facet |
Iusem, N.D. De Larminat, M.A. Tezon, J.G. Blaquier, J.A. Belocopitow, E. |
| author_sort |
Iusem, N.D. |
| title |
Androgen dependence of protein N-glycosylation in rat epididymis |
| title_short |
Androgen dependence of protein N-glycosylation in rat epididymis |
| title_full |
Androgen dependence of protein N-glycosylation in rat epididymis |
| title_fullStr |
Androgen dependence of protein N-glycosylation in rat epididymis |
| title_full_unstemmed |
Androgen dependence of protein N-glycosylation in rat epididymis |
| title_sort |
androgen dependence of protein n-glycosylation in rat epididymis |
| url |
http://hdl.handle.net/20.500.12110/paper_00137227_v114_n4_p1448_Iusem |
| work_keys_str_mv |
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| _version_ |
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