PRL-1 protein promotes ERK1/2 and RhoA protein activation through a non-canonical interaction with the Src homology 3 domain of p115 Rho GTPase-activating protein.
Phosphatases of the regenerating liver (PRL) play oncogenic roles in cancer development and metastasis. Although previous studies indicate that PRL-1 promotes cell growth and migration by activating both the ERK1/2 and RhoA pathways, the mechanism by which it activates these signaling events remains unclear. We have identified a PRL-1-binding peptide (Peptide 1) that shares high sequence identity with a conserved motif in the Src homology 3 (SH3) domain of p115 Rho GTPase-activating protein (GAP). p115 RhoGAP directly binds PRL-1 in vitro and in cells via its SH3 domain. Structural analyses of the PRL-1·Peptide 1 complex revealed a novel protein-protein interaction whereby a sequence motif within the PxxP ligand-binding site of the p115 RhoGAP SH3 domain occupies a folded groove within PRL-1. This prevents the canonical interaction between the SH3 domain of p115 RhoGAP and MEKK1 and results in activation of ERK1/2. Furthermore, PRL-1 binding activates RhoA signaling by inhibiting the catalytic activity of p115 RhoGAP. The results demonstrate that PRL-1 binding to p115 RhoGAP provides a coordinated mechanism underlying ERK1/2 and RhoA activation.
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202.
Yunpeng
Y
Bai
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202.
Yong
Y
Luo
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202.
Sijiu
S
Liu
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202.
Lujuan
L
Zhang
Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, Illinois 60115.
Kui
K
Shen
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202.
Yuanshu
Y
Dong
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202.
Chad D
CD
Walls
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202.
Lawrence A
LA
Quilliam
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202.
Clark D
CD
Wells
College of Life Sciences, Nankai University, Tianjin 300071, China.
Youjia
Y
Cao
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, Indiana 46202. Electronic address: zyzhang@iupui.edu.
Zhong-Yin
ZY
Zhang
D020816:Amino Acid Motifs; D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry*; D057809:HEK293 Cells; D006801:Humans; D017874:Immediate-Early Proteins / Q000378:metabolism*; D008024:Ligands; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D011485:Protein Binding; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism*; D064067:Rho Guanine Nucleotide Exchange Factors; D015398:Signal Transduction; D020741:rho GTP-Binding Proteins / Q000378:metabolism; D019061:src-Family Kinases / Q000378:metabolism*
D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; D017874:Immediate-Early Proteins; D008024:Ligands; D008565:Membrane Proteins; D064067:Rho Guanine Nucleotide Exchange Factors; D019061:src-Family Kinases; C535150:MAPK1 protein, human; C535148:Mapk1 protein, mouse; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; C490198:PTP4A1 protein, human; D017027:Protein Tyrosine Phosphatases; C087359:Ptp4a1 protein, mouse; D020741:rho GTP-Binding Proteins