Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 277, Issue 3, Pages 1755-1761Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M109656200
Keywords
-
Categories
Funding
- NCI NIH HHS [CA83261] Funding Source: Medline
- NICHD NIH HHS [HD13563] Funding Source: Medline
- NIDCR NIH HHS [DE12354] Funding Source: Medline
- NIGMS NIH HHS [GM20528] Funding Source: Medline
Ask authors/readers for more resources
beta-O-linked N-acetylglucosamine (0-GIcNAc) is an abundant and dynamic post-translational modification implicated in protein regulation that appears to be functionally more similar to phosphorylation than to classical glycosylation. There are nucleocytoplasmic enzymes for the attachment and removal of 0-GIcNAc. Here, we further characterize the recently cloned beta-N-acetylglucosaminidase, O-GlcNAcase. Both recombinant and purified endogenous O-GlcNAcase rapidly release free GlcNAc from O-GlcNAc-modified peptide substrates. The recombinant enzyme functions as a monomer and has kinetic parameters (K-m = 1.1 mm for paranitrophenyl-GleNAc, k(cat) = 1 s(-1)) that are similar to those of lysosomal hexosaminidases. The endogenous O-GlcNAcase appears to be in a complex with other proteins and is predominantly localized to the cytosol. Overexpression of the enzyme in living cells results in decreased O-GlcNAc modification of nucleocytoplasmic proteins. Finally, we show that the enzyme is a substrate for caspase-3 but, suprisingly, the cleavage has no effect on in vitro O-GlcNAcase activity. These studies support the identification of this protein as an O-GlcNAcase and identify important interactions and modifications that may regulate the enzyme and O-GlcNAc cycling.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available