title: Phosphorylation of the MET receptor on juxtamembrane tyrosine residue 1001 inhibits its caspase-dependent cleavage.
abstract: The MET tyrosine kinase is the hepatocyte growth factor/scatter factor (HGF/SF) receptor, which elicits multiple biological responses in epithelial cells, including cell survival. We previously demonstrated that in stress conditions, the MET receptor is cleaved by caspases within its juxtamembrane region, generating a pro-apoptotic intracellular fragment of 40 kDa. The caspase cleavage site at aspartic acid D1000 is adjacent to tyrosine Y1001, which when phosphorylated upon MET activation, is involved in CBL recruitment, allowing receptor ubiquitination and down regulation. Scanning mutagenesis of the MET juxtamembrane region led us to demonstrate that V999 and D1000 are essential for the caspase cleavage, while D1000 and Y1001 are essential for CBL recruitment. By examining whether overlapping of these sites leads to a functional interference, an inverse relationship was found between generation of p40 MET and phosphorylation of MET, with a direct involvement of phosphorylated Y1001 in protecting MET against its caspase cleavage. A molecular modeling analysis of caspase 3 interaction with the juxtamembrane region of MET confirmed that phosphorylation of this tyrosine is not compatible with its recognition by active caspase 3. These data demonstrate a direct protection mechanism of an activated phosphorylated MET receptor, against its caspase-dependent cleavage.
authors.affiliation: CNRS UMR 8161, Institut de Biologie de Lille, Université Lille-Nord de France, Institut Pasteur de Lille, IFR142, LILLE, France.
authors.forename: Julien
authors.initials: J
authors.lastname: Deheuninck
authors.forename: Gautier
authors.initials: G
authors.lastname: Goormachtigh
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Foveau
authors.forename: Zongling
authors.initials: Z
authors.lastname: Ji
authors.forename: Catherine
authors.initials: C
authors.lastname: Leroy
authors.forename: Frédéric
authors.initials: F
authors.lastname: Ancot
authors.forename: Vincent
authors.initials: V
authors.lastname: Villeret
authors.forename: David
authors.initials: D
authors.lastname: Tulasne
authors.forename: Véronique
authors.initials: V
authors.lastname: Fafeur
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D020169:Caspases / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000502:physiology; D003198:Computer Simulation; D004285:Dogs; D006367:HeLa Cells; D006801:Humans; D010766:Phosphorylation; D054730:Protein Interaction Domains and Motifs; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D050721:Proto-Oncogene Proteins c-cbl / Q000378:metabolism; D019859:Proto-Oncogene Proteins c-met; D017978:Receptors, Growth Factor / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: D011518:Proto-Oncogene Proteins; D017978:Receptors, Growth Factor; D014443:Tyrosine; D050721:Proto-Oncogene Proteins c-cbl; C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met; D020169:Caspases