title: Tumor necrosis factor-alpha converting enzyme (TACE) regulates epidermal growth factor receptor ligand availability.
abstract: We previously implicated tumor necrosis factor-alpha converting enzyme (TACE/ADAM17) in the processing of the integral membrane precursor to soluble transforming growth factor-alpha (TGF-alpha), pro-TGF-alpha. Here we examined TGF-alpha processing in a physiologically relevant cell model, primary keratinocytes, showing that cells lacking TACE activity shed dramatically less TGF-alpha as compared with wild-type cultures and that TGF-alpha cleavage was partially restored by infection of TACE-deficient cells with TACE-encoding adenovirus. Moreover, cotransfection of TACE-deficient fibroblasts with pro-TGF-alpha and TACE cDNAs increased shedding of mature TGF-alpha with concomitant conversion of cell-associated pro-TGF-alpha to a processed form. Purified TACE accurately cleaved pro-TGF-alpha in vitro at the N-terminal site and also cleaved a soluble form of pro-TGF-alpha containing only the ectodomain at the C-terminal site. In vitro, TACE accurately cleaved peptides corresponding to cleavage sites of several epidermal growth factor (EGF) family members, and transfection of TACE into TACE-deficient cells increased the shedding of amphiregulin and heparin-binding EGF (HB-EGF) proteins. Consistent with the hypothesis that TACE regulates EGF receptor (EGFR) ligand availability in vivo, mice heterozygous for Tace and homozygous for an impaired EGFR allele (wa-2) were born with open eyes significantly more often than Tace(+/+)Egfr(wa-2)(/)(wa-2) counterparts. Collectively, these data support a broad role for TACE in the regulated shedding of EGFR ligands.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
authors.forename: Susan Wohler
authors.initials: SW
authors.lastname: Sunnarborg
authors.forename: C Leann
authors.initials: CL
authors.lastname: Hinkle
authors.forename: Mary
authors.initials: M
authors.lastname: Stevenson
authors.forename: William E
authors.initials: WE
authors.lastname: Russell
authors.forename: Christina S
authors.initials: CS
authors.lastname: Raska
authors.forename: Jacques J
authors.initials: JJ
authors.lastname: Peschon
authors.forename: Beverly J
authors.initials: BJ
authors.lastname: Castner
authors.forename: Mary J
authors.initials: MJ
authors.lastname: Gerhart
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Paxton
authors.forename: Roy A
authors.initials: RA
authors.lastname: Black
authors.forename: David C
authors.initials: DC
authors.lastname: Lee
mesh_terms: D051722:ADAM Proteins; D000072198:ADAM17 Protein; D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D008666:Metalloendopeptidases / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010641:Phenotype; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D016211:Transforming Growth Factor alpha / Q000502:physiology
chemical_list: D017931:DNA Primers; D008024:Ligands; D016211:Transforming Growth Factor alpha; D066246:ErbB Receptors; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000072198:ADAM17 Protein; C000606463:Adam17 protein, mouse