Evidence for regulation of the tumor necrosis factor alpha-convertase (TACE) by protein-tyrosine phosphatase PTPH1.
Tumor necrosis factor alpha-convertase (TACE) is a metalloprotease-disintegrin involved in the ectodomain shedding of several proteins and is critical for proper murine development. TACE-mediated ectodomain shedding is regulated, and the cytoplasmic domain of TACE contains several potential signaling motifs, suggesting that this domain may play a role in regulating the metalloprotease activity. Here we report that the protein-tyrosine phosphatase PTPH1, which contains both a band 4.1 domain and a single PDZ domain, can interact with the cytoplasmic domain of TACE. The interaction was initially observed in a yeast two-hybrid screen and was confirmed using an in vitro binding assay and co-immunoprecipitations from eukaryotic cell extracts. The interaction is mediated via binding of the PDZ domain of PTPH1 to the COOH terminus of TACE. The latter represents a novel group I PDZ binding sequence characterized by a terminal cysteine residue. In co-expression experiments, significantly lower levels of TACE were observed in the presence of catalytically active forms of PTPH1 compared with catalytically inactive forms of PTPH1. Furthermore, phorbol ester-stimulated shedding of the TACE substrate tumor necrosis factor-alpha was decreased in cells expressing catalytically active PTPH1 compared with inactive PTPH1. Taken together, these results suggest that PTPH1 may be a negative regulator of TACE levels and function, and thus provide the first evidence for the regulation of TACE through a cytoplasmic protein.
Graduate Program in Physiology, Biophysics and Molecular Medicine, Weill Graduate School of Medical Science of Cornell University, New York, New York 10021, USA.
Yufang
Y
Zheng
Johannes
J
Schlondorff
Carl P
CP
Blobel
D051722:ADAM Proteins; D000072198:ADAM17 Protein; D019943:Amino Acid Substitution; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000235:genetics; D005822:Genetic Vectors; D006801:Humans; D007700:Kinetics; D008666:Metalloendopeptidases / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D054589:Protein Tyrosine Phosphatase, Non-Receptor Type 3; D017027:Protein Tyrosine Phosphatases / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D004268:DNA-Binding Proteins; C052130:GAL4 protein, S cerevisiae; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C516656:PTPN3 protein, human; D054589:Protein Tyrosine Phosphatase, Non-Receptor Type 3; D017027:Protein Tyrosine Phosphatases; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human