Shedding-generated Met receptor fragments can be routed to either the proteasomal or the lysosomal degradation pathway.
Traffic
; 13(9): 1261-72, 2012 Sep.
Article
em En
| MEDLINE
| ID: mdl-22672335
ABSTRACT
The receptor tyrosine kinase Met and its ligand, the hepatocyte growth factor/scatter factor, are essential for embryonic development, whereas deregulation of Met signaling pathways is associated with tumorigenesis and metastasis. The presenilin-regulated intramembrane proteolysis (PS-RIP) is involved in ligand-independent downregulation of Met. This proteolytic process involves shedding of the Met extracellular domain followed by γ-secretase cleavage, generating labile intracellular fragments degraded by the proteasome. We demonstrate here that upon shedding both generated Met N- and C-terminal fragments are degraded directly in the lysosome, with C-terminal fragments escaping γ-secretase cleavage. PS-RIP and lysosomal degradation are complementary, because their simultaneous inhibition induces synergistic accumulation of fragments. Met N-terminal fragments associate with the high-affinity domain of HGF/SF, confirming its decoy activity which could be reduced through their routing to the lysosome at the expense of extracellular release. Finally, the DN30 monoclonal antibody inducing Met shedding promotes receptor degradation through induction of both PS-RIP and the lysosomal pathway. Thus, we demonstrate that Met shedding initiates a novel lysosomal degradation which participates to ligand-independent downregulation of the receptor.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Proteínas Proto-Oncogênicas c-met
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Complexo de Endopeptidases do Proteassoma
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Lisossomos
Limite:
Animals
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Humans
Idioma:
En
Revista:
Traffic
Assunto da revista:
FISIOLOGIA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
França