GLYCOSYLATION OF RAT NGF RECEPTOR ECTODOMAIN IN THE YEAST SACCHAROMYCES-CEREVISIAE

Here we studied the glycosylation of a mammalian protein, the ectodoma in of rat nerve growth factor receptor (NGFR(e)), in Saccharomyces cer evisiae. NGFR(e) is secreted to the culture medium of S. cerevisiae if it is fused to a polypeptide (hsp150 Delta) carrier. The hsp150 Delta -carrier has 95 serine and threonine residues, which mere extensively O-glycosylated. In spite of 41 potential sites, NGFR(e) lacked O-glyca ns, whether fused to the carrier or not. Distortion of the conformatio n of NGFR(e) by inhibition of disulfide formation did not promote O-gl ycosylation, whereas N-glycosylation was enhanced, Thus, the serine an d threonine residues of the hsp150 Delta-NGFR(e) fusion protein were h ighly selectively O-glycosylated.