title: Low and high affinity receptors mediate cellular uptake of heparanase.
abstract: Heparanase is an endoglycosidase which cleaves heparan sulfate and hence participates in degradation and remodeling of the extracellular matrix. Importantly, heparanase activity correlated with the metastatic potential of tumor-derived cells, attributed to enhanced cell dissemination as a consequence of heparan sulfate cleavage and remodeling of the extracellular matrix barrier. Heparanase has been characterized as a glycoprotein, yet glycan biochemical analysis was not performed to date. Here, we applied the Qproteometrade mark GlycoArray kit to perform glycan analysis of heparanase, and compared the kit results with the more commonly used biochemical analyses. We employed fibroblasts isolated from patients with I-cell disease (mucolipidosis II), fibroblasts deficient of low density lipoprotein receptor-related protein and fibroblasts lacking mannose 6-phosphate receptor, to explore the role of mannose 6-phosphate in heparanase uptake. Iodinated heparanase has been utilized to calculate binding affinity. We provide evidence for hierarchy of binding to cellular receptors as a function of heparanase concentration. We report the existence of a high affinity, low abundant (i.e., low density lipoprotein receptor-related protein, mannose 6-phosphate receptor), as well as a low affinity, high abundant (i.e., heparan sulfate proteoglycan) receptors that mediate heparanase binding, and suggest that these receptors co-operate to establish high affinity binding sites for heparanase, thus maintaining extracellular retention of the enzyme tightly regulated.
authors.affiliation: Cancer and Vascular Biology Research Center, Bruce Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel.
authors.forename: Olga
authors.initials: O
authors.lastname: Ben-Zaken
authors.forename: Itay
authors.initials: I
authors.lastname: Shafat
authors.forename: Svetlana
authors.initials: S
authors.lastname: Gingis-Velitski
authors.forename: Haim
authors.initials: H
authors.lastname: Bangio
authors.forename: Idil Kasuto
authors.initials: IK
authors.lastname: Kelson
authors.forename: Tal
authors.initials: T
authors.lastname: Alergand
authors.forename: Yehudit
authors.initials: Y
authors.lastname: Amor
authors.forename: Ruth Ben-Yakar
authors.initials: RB
authors.lastname: Maya
authors.forename: Israel
authors.initials: I
authors.lastname: Vlodavsky
authors.forename: Neta
authors.initials: N
authors.lastname: Ilan
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D006224:Cricetinae; D005109:Extracellular Matrix / Q000201:enzymology / Q000378:metabolism; D005347:Fibroblasts / Q000201:enzymology / Q000378:metabolism*; D005966:Glucuronidase / Q000302:isolation & purification / Q000378:metabolism*; D006497:Heparan Sulfate / Q000378:metabolism*; D006801:Humans; D008360:Mannosephosphates / Q000378:metabolism*; D009081:Mucolipidoses / Q000201:enzymology / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000378:metabolism*; D011994:Recombinant Proteins; D000099175:Heparanase
chemical_list: D005966:Glucuronidase; D006497:Heparan Sulfate; D008360:Mannosephosphates; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D000099175:Heparanase; C027693:mannose-6-phosphate