Secretion of heparanase protein is regulated by glycosylation in human tumor cell lines.
The endo-beta-d-glucuronidase, heparanase, is capable of specifically degrading heparan sulfate, and this activity is associated with the metastatic potential of tumor cells. The predicted amino acid sequence of heparanase includes six putative N-glycosylation sites; however, the precise biochemical role of glycosylated heparanase remains unknown. In this study, we examined the link between glycosylation and the function of heparanase in human tumor cell lines. Heparanase protein was glycosylated at six Asn residues in human tumor cell lines. Treatment with a glycosylation inhibitor demonstrated that glycosylation was not required for the activity of heparanase. However, glycosylation affected the kinetics of endoplasmic reticulum-to-Golgi transport and of secretion of the enzyme.
Antibiotics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Siro
S
Simizu
Keisuke
K
Ishida
Michal K
MK
Wierzba
Hiroyuki
H
Osada
D045744:Cell Line, Tumor; D005966:Glucuronidase / Q000378:metabolism*; D006031:Glycosylation; D006801:Humans; D009369:Neoplasms / Q000201:enzymology* / Q000378:metabolism; D021381:Protein Transport; D000099175:Heparanase
D005966:Glucuronidase; D000099175:Heparanase