The adaptor function of SHP-2 downstream of the prolactin receptor is required for the recruitment of p29, a substrate of SHP-2.
SHP-2, a cytosolic protein tyrosine phosphatase with two SH2 domains and multiple tyrosine phosphorylation sites, contributes to signal transduction as an enzyme and/or adaptor molecule. Here we demonstrate that prolactin (PRL) stimulation of the PRL-responsive Nb2 cells, a rat lymphoma cell line, and T47D cells, a human breast cancer cell line, lead to the complex formation of SHP-2 and growth factor receptor-bound protein-2 (grb2). Using transient co-overexpression studies of the prolactin receptor (PRLR) and several tyrosine to phenylalanine mutants of SHP-2, we show that grb2 associates with SHP-2 through the C-terminal tyrosine residues of SHP-2, Y(546) and Y(584). Furthermore, in this study, we found a highly phosphorylated, 29-kDa protein (p29), a substrate of SHP-2. The recruitment of p29 to SHP-2 requires the carboxy-terminal tyrosine residues of SHP-2 (Y(546) and Y(584)). Together, our results indicate that SHP-2 may function as an adaptor molecule downstream of the PRLR and highlight a new recruitment mechanism of SHP-2 substrates.
Minoo
Parham
P
Division of Hematology, Department of Medicine, Molecular Oncology Group, H5-81, Royal Victoria Hospital, McGill University, 687 Pine Avenue West, Montreal, Quebec, Canada H3A 1A1.
Chughtai
Naila
N
Campiglio
Manuela
M
Stein-Gerlach
Matthias
M
Lebrun
Jean-Jacques
JJ
Ullrich
Axel
A
Ali
Suhad
S
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport / Q000378:metabolism; D000818:Animals; D001943:Breast Neoplasms; D051380:GRB2 Adaptor Protein; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D053614:Janus Kinase 2; D008223:Lymphoma; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011233:Precipitin Tests; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011506:Proteins / Q000378:metabolism; D011518:Proto-Oncogene Proteins; D051381:Rats; D011981:Receptors, Prolactin / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*; D013379:Substrate Specificity; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; C495950:Grb2 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D010750:Phosphoproteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D011981:Receptors, Prolactin; D019000:Phosphotyrosine; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; C507924:JAK2 protein, human; C507927:Jak2 protein, rat; D053614:Janus Kinase 2; C516724:PTPN11 protein, human; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases; C516727:Ptpn11 protein, rat