All-or-none N-glycosylation in primate follicle-stimulating hormone beta-subunits.
Human FSH exists as two major glycoforms designated, tetra-glycosylated and di-glycosylated hFSH. The former possesses both alpha- and beta-subunit carbohydrates while the latter possesses only alpha-subunit carbohydrate. Western blotting differentiated the glycosylated, 24,000 M(r) hFSHbeta band from the non-glycosylated 21,000 M(r) FSHbeta band. Postmenopausal urinary hFSH preparations possessed 75-95% 24,000 M(r) hFSHbeta, while pituitary hFSH immunopurified from 21- to 43-year-old females and 21-43-year-old males possessed only 35-40% 24,000 M(r) hFSHbeta. The pituitary hFSH from a postmenopausal woman on estrogen replacement was 75% 21,000 M(r) hFSHbeta. Other immunopurified postmenopausal pituitary hFSH preparations possessed 50-60% 21,000 M(r) hFSHbeta. Gel filtration removed predominantly 21,000 M(r) free hFSHbeta and reduced its abundance to 13-22% in postmenopausal pituitary hFSH heterodimer preparations. A major regulatory mechanism for FSH glycosylation involves control of beta-subunit N-glycosylation, possibly by inhibition of oligosaccharyl transferase. Two primate species exhibited the same all-or-none pattern of pituitary FSHbeta glycosylation.
Bousfield
George R
GR
Wichita State University, Wichita, KS, United States. george.bousfield@wichita.edu
Butnev
Vladimir Y
VY
Walton
Wendy J
WJ
Nguyen
Van T
VT
Huneidi
Jennifer
J
Singh
Vinod
V
Kolli
V S Kumar
VS
Harvey
David J
DJ
Rance
Naomi E
NE
D000328:Adult; D000368:Aged; D000818:Animals; D015153:Blotting, Western; D002850:Chromatography, Gel; D005260:Female; D037201:Follicle Stimulating Hormone, beta Subunit / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D006031:Glycosylation; D006801:Humans; D008251:Macaca / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000378:metabolism; D010053:Ovary / Q000601:surgery; D010902:Pituitary Gland / Q000737:chemistry; D020033:Protein Isoforms / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
C043517:2-(4-isothiocyanatophenoxy)-1,3,2-dioxaphosphinene 2-oxide; D037201:Follicle Stimulating Hormone, beta Subunit; D009943:Organophosphorus Compounds; D020033:Protein Isoforms