Teis Jensen <t.jensen at immi.ku.dk> asked about degradation of O-glycoproteins.
Yes, just like N-glycoproteins, O-glycoproteins are also degraded in the lyso-
somes by a combination of exoglycosidases along with proteases. From our
current understanding of how lysosomal enzymes are targed (mainly via mannose-
6-phosphate pathway) and that endosomes will be "matured" into lysosomes, som
e of the reactions could have occurred in the endosomal compartment. Exoglyco-
sidases involved include n-acetylneuraminidase, b-galactosidase, a- and b-
mannosidase, a-L-fucosidase, and of corse, a-N-acetylgalactosaminidase. The
last enzyme is deficient in a human pathological condition termed neuronal
dystrophy or Schindler's syndrome.
You can get most of the above infomation in the latest edition of "Molecular
and metabolic basis of disease" edited by Charles Scriver et al (7th edn, 1995).
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* Ke-Wei Zhao, Ph.D. Phone: (310)825-8722
* Department of Biological Chemistry Fax: (310)206-5272
* UCLA School of Medicine, CHS 33-257 e-mail: kzhao at biovx1.biology.ucla.edu
* Los Angeles, CA 90095-1737
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