Format

Send to

Choose Destination
J Biol Chem. 2008 Aug 29;283(35):23557-66. doi: 10.1074/jbc.M804116200. Epub 2008 Jun 27.

Characterization of beta-N-acetylglucosaminidase cleavage by caspase-3 during apoptosis.

Author information

1
Departments of Biological Chemistry and Neuroscience, Johns Hopkins University School of Medicine, 725 N. Wolfe Street, Baltimore, MD 21205-2185, USA.

Abstract

Beta-O-linked N-acetylglucosamine is a dynamic post-translational modification involved in protein regulation in a manner similar to phosphorylation. Removal of N-acetylglucosamine is regulated by beta-N-acetylglucosaminidase (O-GlcNAcase), which was previously shown to be a substrate of caspase-3 in vitro. Here we show that O-GlcNAcase is cleaved by caspase-3 into two fragments during apoptosis, an N-terminal fragment containing the O-GlcNAcase active site and a C-terminal fragment containing a region with homology to GCN5 histone acetyl-transferases. The caspase-3 cleavage site of O-GlcNAcase, mapped by Edman sequencing, is a noncanonical recognition site that occurs after Asp-413 of the SVVD sequence in human O-GlcNAcase. A point mutation, D413A, abrogates cleavage by caspase-3 both in vitro and in vivo. Finally, we show that O-GlcNAcase activity is not affected by caspase-3 cleavage because the N- and C-terminal O-GlcNAcase fragments remain associated after the cleavage. Furthermore, when co-expressed simultaneously in the same cell, the N-terminal and C-terminal caspase fragments associate to reconstitute O-GlcNAcase enzymatic activity. These studies support the identification of O-GlcNAcase as a caspase-3 substrate with a novel caspase-3 cleavage site and provide insight about O-GlcNAcase regulation during apoptosis.

PMID:
18586680
PMCID:
PMC2527095
DOI:
10.1074/jbc.M804116200
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center