Evidence for N-glycosylation and ubiquitination of the prolactin receptor expressed in a baculovirus-insect cell system.
The molecular mass of the rabbit prolactin receptor (rbPRLR) deduced from cDNA cloning is 66 kDa. However, the molecular mass of the full-length receptor expressed in the insect Sf9 cells was found to be 94 kDa. In order to explain this discrepancy, we analyzed the possible post-translational modifications of the PRLR. Sf9 cells were infected with recombinant baculoviruses in the presence of tunicamycin, an inhibitor of N-glycosylation. Results showed that an additional approximately 9 kDa of the extracellular domain could be attributed to the N-glycosylation and another additional approximately 20 kDa covalent modification occurred in the cytoplasmic part of the receptor. Western blot analysis, using anti-ubiquitin antibodies, revealed that the rbPRLR was ubiquitinated in its cytoplasmic domain.
Cahoreau
C
C
Laboratoire de Pathologie Comparée, Institut National de la Recherche Agronomique, CNRS UA 1184, St-Christol-Lez-Alès, France.
Garnier
L
L
Djiane
J
J
Devauchelle
G
G
Cerutti
M
M
D000818:Animals; D016367:Baculoviridae; D006031:Glycosylation; D066298:In Vitro Techniques; D009036:Moths; D011499:Protein Processing, Post-Translational; D011817:Rabbits; D011981:Receptors, Prolactin / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism*; D014452:Ubiquitins / Q000378:metabolism
D011981:Receptors, Prolactin; D011994:Recombinant Proteins; D014452:Ubiquitins