The novel role of the C-terminal region of SHP-2. Involvement of Gab1 and SHP-2 phosphatase activity in Elk-1 activation.
SHP-2, a nontransmembrane-type protein-tyrosine phosphatase that contains two Src homology 2 (SH2) domains, is thought to participate in growth factor signal transduction pathways via SH2 domain interactions. To determine the role of each region of SHP-2 in platelet-derived growth factor signaling assayed by Elk-1 activation, we generated six deletion mutants of SHP-2. The large SH2 domain deletion SHP-2 mutant composed of amino acids 198-593 (SHP-2-(198-593)), but not the smaller SHP-2-(399-593), showed significantly higher SHP-2 phosphatase activity in vitro. In contrast, SHP-2-(198-593) mutant inhibited wild type SHP-2 phosphatase activity, whereas SHP-2-(399-593) mutant increased activity. To understand these functional changes, we focused on the docking protein Gab1 that assembles signaling complexes. Pull-down experiments with Gab1 suggested that the C-terminal region of SHP-2 as well as the SH2 domains (N-terminal region) associated with Gab1, but the SHP-2-(198-593) mutant did not associate with Gab1. SHP-2-(1-202) or SHP-2-(198-593) inhibited platelet-derived growth factorinduced Elk-1 activation, but SHP-2-(399-593) increased Elk-1 activation. Co-expression of SHP-2-(1-202) with SHP-2-(399-593) inhibited SHP-2-(399-593)/Gab1 interaction, and the SHP-2-(399-593) mutant induced SHP-2 phosphatase and Elk-1 activation, supporting the autoinhibitory effect of SH2 domains on the C-terminal region of SHP-2. These data suggest that both SHP-2/Gab1 interaction in the C-terminal region of SHP-2 and increased SHP-2 phosphatase activity are important for Elk-1 activation. Furthermore, we identified a novel sequence for SHP-2/Gab1 interactions in the C-terminal region of SHP-2.
Huang
Qunhua
Q
Center for Cardiovascular Research, University of Rochester, Rochester, New York 14642, USA.
Lerner-Marmarosh
Nicole
N
Che
Wenyi
W
Ohta
Shinsuke
S
Osawa
Masaki
M
Yoshizumi
Masanori
M
Glassman
Michael
M
Yan
Chen
C
Berk
Bradford C
BC
Abe
Jun-Ichi
J
D000818:Animals; D015153:Blotting, Western; D016466:CHO Cells; D020134:Catalytic Domain; D006224:Cricetinae; D004268:DNA-Binding Proteins; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation; D017353:Gene Deletion; D047908:Intracellular Signaling Peptides and Proteins; D008954:Models, Biological; D009154:Mutation; D010750:Phosphoproteins / Q000378:metabolism / Q000502:physiology*; D010766:Phosphorylation; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases / Q000502:physiology*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases; D015398:Signal Transduction; D013997:Time Factors; D014157:Transcription Factors; D014162:Transfection; D014443:Tyrosine / Q000378:metabolism; D050807:ets-Domain Protein Elk-1
D004268:DNA-Binding Proteins; D047908:Intracellular Signaling Peptides and Proteins; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D014157:Transcription Factors; D050807:ets-Domain Protein Elk-1; D014443:Tyrosine; D054592:Protein Tyrosine Phosphatase, Non-Receptor Type 11; D017027:Protein Tyrosine Phosphatases; D054593:SH2 Domain-Containing Protein Tyrosine Phosphatases