Noonan syndrome-associated SHP-2/Ptpn11 mutants enhance SIRPalpha and PZR tyrosyl phosphorylation and promote adhesion-mediated ERK activation.
J Biol Chem
; 283(22): 15328-38, 2008 May 30.
Article
em En
| MEDLINE
| ID: mdl-18378677
ABSTRACT
Noonan syndrome (NS) is an autosomal dominant disorder that is associated with multiple developmental abnormalities. Activated mutations of the protein-tyrosine phosphatase, SHP-2/PTPN11, have been reported in approximately 50% of NS cases. Despite being activated, NS-associated SHP-2 mutants require plasma membrane proximity to evoke disease-associated signaling. Here we show that NS-associated SHP-2 mutants induce hypertyrosyl phosphorylation of the transmembrane glycoproteins, SIRPalpha (signal-regulatory protein alpha) and PZR (protein zero-related), resulting in their increased association with NS-associated SHP-2 mutants. NS-associated SHP-2 mutants enhanced SIRPalpha and PZR tyrosyl phosphorylation either by impairing SIRPalpha dephosphorylation or by promoting PZR tyrosyl phosphorylation. Importantly, during embryogenesis in a mouse model of NS, SIRPalpha and PZR were hypertyrosyl-phosphorylated and bound increased levels of the NS-associated SHP-2 mutant. SIRPalpha and PZR have been implicated in extracellular matrix-dependent signaling. Mouse embryonic fibroblasts derived from a mouse model of NS displayed enhanced ERK activation in response to fibronectin plating. Knockdown of SIRPalpha and PZR in these cells attenuated the enhanced activation of ERK following fibronectin plating. Thus, SIRPalpha and PZR serve as scaffolds that facilitate plasma membrane recruitment and signaling of NS-associated SHP-2 mutants.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Fosfoproteínas
/
Receptores Imunológicos
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Transdução de Sinais
/
Membrana Celular
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Peptídeos e Proteínas de Sinalização Intracelular
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Proteína Tirosina Fosfatase não Receptora Tipo 11
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Mutação
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Síndrome de Noonan
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
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Humans
Idioma:
En
Ano de publicação:
2008
Tipo de documento:
Article