Low and high affinity receptors mediate cellular uptake of heparanase.
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.
Ben-Zaken
Olga
O
Cancer and Vascular Biology Research Center, Bruce Rappaport Faculty of Medicine, Technion, Haifa 31096, Israel.
Shafat
Itay
I
Gingis-Velitski
Svetlana
S
Bangio
Haim
H
Kelson
Idil Kasuto
IK
Alergand
Tal
T
Amor
Yehudit
Y
Maya
Ruth Ben-Yakar
RB
Vlodavsky
Israel
I
Ilan
Neta
N
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
D005966:Glucuronidase; D006497:Heparan Sulfate; D008360:Mannosephosphates; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D000099175:Heparanase; C027693:mannose-6-phosphate