title: Nardilysin enhances ectodomain shedding of heparin-binding epidermal growth factor-like growth factor through activation of tumor necrosis factor-alpha-converting enzyme.
abstract: Like other members of the epidermal growth factor family, heparin-binding epidermal growth factor-like growth factor (HB-EGF) is synthesized as a transmembrane protein that can be shed enzymatically to release a soluble growth factor. Ectodomain shedding is essential to the biological functions of HB-EGF and is strictly regulated. However, the mechanism that induces the shedding remains unclear. We have recently identified nardilysin (N-arginine dibasic convertase (NRDc)), a metalloendopeptidase of the M16 family, as a protein that specifically binds HB-EGF (Nishi, E., Prat, A., Hospital, V., Elenius, K., and Klagsbrun, M. (2001) EMBO J. 20, 3342-3350). Here, we show that NRDc enhances ectodomain shedding of HB-EGF. When expressed in cells, NRDc enhanced the shedding in cooperation with tumor necrosis factor-alpha-converting enzyme (TACE; ADAM17). NRDc formed a complex with TACE, a process promoted by phorbol esters, general activators of ectodomain shedding. NRDc enhanced TACE-induced HB-EGF cleavage in a peptide cleavage assay, indicating that the interaction with NRDc potentiates the catalytic activity of TACE. The metalloendopeptidase activity of NRDc was not required for the enhancement of HB-EGF shedding. Notably, a reduction in the expression of NRDc caused by RNA interference was accompanied by a decrease in ectodomain shedding of HB-EGF. These results indicate the essential role of NRDc in HB-EGF ectodomain shedding and reveal how the shedding is regulated by the modulation of sheddase activity.
authors.affiliation: Molecular Pathology and Biomolecular Characterization Unit, Horizontal Medical Research Organization, Kyoto University, Kyoto 606-8507, Japan. nishi@kuhp.kyoto-u.ac.jp
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Nishi
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Hiraoka
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Yoshida
authors.forename: Katsuya
authors.initials: K
authors.lastname: Okawa
authors.forename: Toru
authors.initials: T
authors.lastname: Kita
mesh_terms: D051722:ADAM Proteins / Q000737:chemistry* / Q000378:metabolism; D000072198:ADAM17 Protein; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002522:Chlorocebus aethiops; D004815:Epidermal Growth Factor / Q000737:chemistry*; D066257:Heparin-binding EGF-like Growth Factor; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D008666:Metalloendopeptidases / Q000378:metabolism / Q000502:physiology*; D010455:Peptides / Q000737:chemistry; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D034622:RNA Interference; D011994:Recombinant Proteins / Q000737:chemistry; D014162:Transfection
chemical_list: C587883:HBEGF protein, human; D066257:Heparin-binding EGF-like Growth Factor; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D011994:Recombinant Proteins; D004815:Epidermal Growth Factor; D051722:ADAM Proteins; D008666:Metalloendopeptidases; C087976:nardilysin; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human