title: Kallikrein-related peptidase 12 hydrolyzes matricellular proteins of the CCN family and modifies interactions of CCN1 and CCN5 with growth factors.
abstract: Kallikrein-related peptidases (KLKs) are an emerging group of secreted serine proteases involved in several physiological and pathological processes. We used a degradomic approach to identify potential substrates of KLK12. MDA-MB-231 cells were treated either with KLK12 or vehicle control, and the proteome of the overlying medium was analyzed by mass spectrometry. CCN1 (cyr61, ctgf, nov) was among the proteins released by the KLK12-treated cells, suggesting that KLK12 might be responsible for the shedding of this protein from the cell surface. Fragmentation of CCN1 by KLK12 was further confirmed in vitro, and the main cleavage site was localized in the hinge region between the first and second half of the recombinant protein. KLK12 can target all six members of the CCN family at different proteolytic sites. Limited proteolysis of CCNs (cyr61, ctgf, nov) was also observed in the presence of other members of the KLK family, such as KLK1, KLK5, and KLK14, whereas KLK6, KLK11, and KLK13 were unable to fragment CCNs. Because KLK12 seems to have a role in angiogenesis, we investigated the relations between KLK12, CCNs, and several factors known to be involved in angiogenesis. Solid phase binding assays showed that fragmentation of CCN1 or CCN5 by KLK12 prevents VEGF(165) binding, whereas it also triggers the release of intact VEGF and BMP2 from the CCN complexes. The KLK12-mediated release of TGF-β1 and FGF-2, either as intact or truncated forms, was found to be concentration-dependent. These findings suggest that KLK12 may indirectly regulate the bioavailability and activity of several growth factors through processing of their CCN binding partners.
authors.affiliation: INSERM U618-Université François Rabelais, Faculté de Médecine, 2 bis bd Tonnellé, 37032 Tours, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: Guillon-Munos
authors.forename: Katerina
authors.initials: K
authors.lastname: Oikonomopoulou
authors.forename: Noémie
authors.initials: N
authors.lastname: Michel
authors.forename: Chistopher R
authors.initials: CR
authors.lastname: Smith
authors.forename: Agnès
authors.initials: A
authors.lastname: Petit-Courty
authors.forename: Sylvie
authors.initials: S
authors.lastname: Canepa
authors.forename: Pascale
authors.initials: P
authors.lastname: Reverdiau
authors.forename: Nathalie
authors.initials: N
authors.lastname: Heuzé-Vourc'h
authors.forename: Eleftherios P
authors.initials: EP
authors.lastname: Diamandis
authors.forename: Yves
authors.initials: Y
authors.lastname: Courty
mesh_terms: D055511:CCN Intercellular Signaling Proteins; D045744:Cell Line, Tumor; D055515:Cysteine-Rich Protein 61 / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006706:Homeostasis / Q000187:drug effects; D006801:Humans; D006868:Hydrolysis; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D007610:Kallikreins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology*; D008168:Lung / Q000166:cytology / Q000378:metabolism / Q000473:pathology; D008175:Lung Neoplasms / Q000235:genetics; D011485:Protein Binding / Q000187:drug effects; D021381:Protein Transport / Q000187:drug effects; D040901:Proteomics; D012097:Repressor Proteins; D015203:Reproducibility of Results; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D055511:CCN Intercellular Signaling Proteins; C413323:CCN5 protein, human; D055515:Cysteine-Rich Protein 61; D036341:Intercellular Signaling Peptides and Proteins; D012097:Repressor Proteins; D014157:Transcription Factors; C497170:KLK12 protein, human; D007610:Kallikreins