title: Proteomic Identification of Cysteine Cathepsin Substrates Shed from the Surface of Cancer Cells.
abstract: Extracellular cysteine cathepsins are known to drive cancer progression, but besides degradation of extracellular matrix proteins little is known about their physiological substrates and thus the molecular mechanisms they deploy. One of the major mechanisms used by other extracellular proteases to facilitate cancer progression is proteolytic release of the extracellular domains of transmembrane proteins or ectodomain shedding. Here we show using a mass spectrometry-based approach that cathepsins L and S act as sheddases and cleave extracellular domains of CAM adhesion proteins and transmembrane receptors from the surface of cancer cells. In cathepsin S-deficient mouse pancreatic cancers, processing of these cathepsin substrates is highly reduced, pointing to an essential role of cathepsins in extracellular shedding. In addition to influencing cell migration and invasion, shedding of surface proteins by extracellular cathepsins impacts intracellular signaling as demonstrated for regulation of Ras GTPase activity, thereby providing a putative mechanistic link between extracellular cathepsin activity and cancer progression. The MS data is available via ProteomeXchange with identifier PXD002192.
authors.affiliation: From the ‡Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia; §International Postgraduate School Jozef Stefan, Jamova 39, SI-1000 Ljubljana, Slovenia;
authors.forename: Barbara
authors.initials: B
authors.lastname: Sobotič
authors.affiliation: From the ‡Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia; §International Postgraduate School Jozef Stefan, Jamova 39, SI-1000 Ljubljana, Slovenia;
authors.forename: Matej
authors.initials: M
authors.lastname: Vizovišek
authors.affiliation: From the ‡Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia; §International Postgraduate School Jozef Stefan, Jamova 39, SI-1000 Ljubljana, Slovenia;
authors.forename: Robert
authors.initials: R
authors.lastname: Vidmar
authors.affiliation: ¶Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium; ‖Department of Medical Protein Research, VIB, B-9000 Ghent, Belgium;
authors.forename: Petra
authors.initials: P
authors.lastname: Van Damme
authors.affiliation: **Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065;
authors.forename: Vasilena
authors.initials: V
authors.lastname: Gocheva
authors.affiliation: **Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, New York 10065;
authors.forename: Johanna A
authors.initials: JA
authors.lastname: Joyce
authors.affiliation: ¶Department of Biochemistry, Ghent University, B-9000 Ghent, Belgium; ‖Department of Medical Protein Research, VIB, B-9000 Ghent, Belgium;
authors.forename: Kris
authors.initials: K
authors.lastname: Gevaert
authors.affiliation: From the ‡Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia; §International Postgraduate School Jozef Stefan, Jamova 39, SI-1000 Ljubljana, Slovenia; ‡‡Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, Jamova cesta 39, SI-1000 Ljubljana, Slovenia;
authors.forename: Vito
authors.initials: V
authors.lastname: Turk
authors.affiliation: From the ‡Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia; ‡‡Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, Jamova cesta 39, SI-1000 Ljubljana, Slovenia; §§Center of Excellence NIN, Ljubljana, Slovenia; ¶¶Faculty of Chemistry and Chemical Technology, University of Ljubljana, Slovenia.
authors.forename: Boris
authors.initials: B
authors.lastname: Turk
authors.affiliation: From the ‡Department of Biochemistry, Molecular and Structural Biology, Jozef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana, Slovenia; ‡‡Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, Jamova cesta 39, SI-1000 Ljubljana, Slovenia; marko.fonovic@ijs.si.
authors.forename: Marko
authors.initials: M
authors.lastname: Fonović
mesh_terms: D000818:Animals; D063646:Carcinogenesis / Q000378:metabolism / Q000473:pathology; D002401:Cathepsin B / Q000378:metabolism*; D056668:Cathepsin L / Q000378:metabolism*; D002403:Cathepsins / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D002465:Cell Movement; D006801:Humans; D008264:Macrophages / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D009361:Neoplasm Invasiveness; D009369:Neoplasms / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D040901:Proteomics / Q000379:methods*; D013379:Substrate Specificity; D018631:ras Proteins / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D002403:Cathepsins; D002401:Cathepsin B; D056668:Cathepsin L; C028217:cathepsin S; D018631:ras Proteins