Tumor necrosis factor-alpha converting enzyme (TACE) regulates epidermal growth factor receptor ligand availability.
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.
Sunnarborg
Susan Wohler
SW
Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
Hinkle
C Leann
CL
Stevenson
Mary
M
Russell
William E
WE
Raska
Christina S
CS
Peschon
Jacques J
JJ
Castner
Beverly J
BJ
Gerhart
Mary J
MJ
Paxton
Raymond J
RJ
Black
Roy A
RA
Lee
David C
DC
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
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