The cell migration protein Grb7 associates with transcriptional regulator FHL2 in a Grb7 phosphorylation-dependent manner.
Grb7 is an adaptor molecule that can mediate signal transduction from multiple cell surface receptors to various downstream signaling pathways. Grb7, along with Grb10 and Grb14, make up the Grb7 protein family. This protein family has been shown to be overexpressed in certain cancers and cancer cell lines. Grb7 and a receptor tyrosine kinase (RTK), erbB2, are overexpressed in 20-30% of breast cancers. Grb7 overexpression has been linked to enhanced cell migration and metastasis, though the participants in these pathways have not been determined. In this study, we report that Grb7 interacts with four and half lim domains isoform 2 (FHL2), a transcription regulator with an important role in oncogenesis, including breast cancer. Additionally, in yeast 2-hybrid (Y2H) assays, we show that the interaction is specific to the Grb7 RA and PH domains. We have also demonstrated that full-length (FL) Grb7 and FHL2 interact in mammalian cells and that Grb7 must be tyrosine phosphorylated for this interaction to occur. Immunofluorescent microscopy demonstrates possible co-localization of Grb7 and FHL2. A model with supporting NMR evidence of Grb7 autoinhibition is proposed.
Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM 88003-8001, USA.
Sharareh
S
Siamakpour-Reihani
Haroula J
HJ
Argiros
Lori J
LJ
Wilmeth
L Lowell
LL
Haas
Tabitha A
TA
Peterson
Dennis L
DL
Johnson
Charles Brad
CB
Shuster
Barbara A
BA
Lyons
D001665:Binding Sites; D015153:Blotting, Western; D002465:Cell Movement / Q000502:physiology*; D005455:Fluorescent Antibody Technique; D051382:GRB7 Adaptor Protein / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D060850:LIM-Homeodomain Proteins; D008958:Models, Molecular; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D019906:Nuclear Magnetic Resonance, Biomolecular; D010766:Phosphorylation; D011485:Protein Binding; D011487:Protein Conformation; D025941:Protein Interaction Mapping; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques; D014443:Tyrosine / Q000378:metabolism
C105987:FHL2 protein, human; C495955:GRB7 protein, human; D018398:Homeodomain Proteins; D060850:LIM-Homeodomain Proteins; D009124:Muscle Proteins; D014157:Transcription Factors; D051382:GRB7 Adaptor Protein; D014443:Tyrosine