Molecular analysis of the pathophysiological binding of the platelet aggregation-inducing factor podoplanin to the C-type lectin-like receptor CLEC-2.
The mucin-type sialoglycoprotein podoplanin (aggrus) is involved in tumor cell-induced platelet aggregation and tumor metastasis. C-type lectin-like receptor-2 (CLEC-2) was recently identified as an endogenous receptor of podoplanin on platelets. However, the pathophysiological importance and function of CLEC-2 have not been elucidated. Here we clarified the pathophysiological interaction between podoplanin and CLEC-2 in vitro and in vivo. Using several deletion mutants of CLEC-2 expressed as Fc chimeras, we first identified an important podoplanin-recognition domain in CLEC-2. Furthermore, the podoplanin-CLEC-2 interaction was confirmed using several deletion mutants of podoplanin expressed as Fc chimeras. Not only the disialyl-core1-attached glycopeptide but also the stereostructure of the podoplanin protein was found to be critical for the CLEC-2-binding activity of podoplanin. We next synthesized various glycopeptides of podoplanin that included both the platelet aggregation-stimulating domain and O-glycan on Thr52. Interestingly, a disialyl-core1-attached glycopeptide was recognized specifically by CLEC-2. Moreover, the anti-podoplanin monoclonal antibody NZ-1 suppressed both the podoplanin-CLEC-2 interaction and podoplanin-induced pulmonary metastasis, suggesting that CLEC-2 is the first pathophysiological receptor of podoplanin to be identified. In summary, we clarified the molecular interaction in vitro and in vivo between a platelet aggregation-inducing factor, podoplanin, and its specific pathophysiological receptor on platelets, CLEC-2. Podoplanin and CLEC-2 might represent promising therapeutic targets in cancer metastasis.
Kato
Yukinari
Y
Research Center for Medical Glycoscience, National Institute of Advanced Industrial Science and Technology, Open Space Laboratory C-2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan.
Kaneko
Mika Kato
MK
Kunita
Akiko
A
Ito
Hiromi
H
Kameyama
Akihiko
A
Ogasawara
Satoshi
S
Matsuura
Nana
N
Hasegawa
Yasushi
Y
Suzuki-Inoue
Katsue
K
Inoue
Osamu
O
Ozaki
Yukio
Y
Narimatsu
Hisashi
H
D000818:Animals; D016466:CHO Cells; D045744:Cell Line, Tumor; D002678:Chimera / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D005260:Female; D005909:Glioblastoma / Q000235:genetics / Q000378:metabolism / Q000556:secondary*; D006020:Glycopeptides / Q000378:metabolism; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000235:genetics / Q000378:metabolism; D037181:Lectins, C-Type / Q000235:genetics* / Q000378:metabolism*; D008175:Lung Neoplasms / Q000235:genetics / Q000378:metabolism / Q000556:secondary*; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D010974:Platelet Aggregation; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D014162:Transfection; D000098853:Podoplanin
D006020:Glycopeptides; D007141:Immunoglobulin Fc Fragments; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D011993:Recombinant Fusion Proteins; C104778:CLEC2B protein, human; C117468:PDPN protein, human; D000098853:Podoplanin