title: Grb7 protein RA domain oligomerization.
abstract: The growth factor receptor bound protein 7 (Grb7) is an adaptor protein that is often coamplified with the erythroblastosis oncogene B 2 receptor in 20% to 30% of breast cancer patients. Grb7 overexpression has been linked to increased cell migration and cancer metastasis. The ras associating and pleckstrin homology domain region of Grb7 has been reported to interact with various other downstream signaling proteins such as four and half Lin11, Isl-1, Mec-3 (LIM) domains isoform 2 and filamin α. These interactions are believed to play a role in regulating Grb7-mediated cell migration function. The full-length Grb7 protein has been shown to dimerize, and the oligomeric state of the Grb7SH2 domain has been extensively studied; however, the oligomerization state of the ras associating and pleckstrin homology domains, and the importance of this oligomerization in Grb7 function, is yet to be fully known. In this study, we characterize the oligomeric state of the Grb7RA domain using size exclusion chromatography, nuclear magnetic resonance, nuclear relaxation studies, glutaraldehyde cross linking, and dynamic light scattering. We report the Grb7RA domain can exist in transient multimeric forms and, based upon modeling results, postulate the potential role of Grb7RA domain oligomerization in Grb7 function.
authors.affiliation: Department of Medicinal Chemistry, University of Michigan, Ann Arbor, MI, USA.|Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM, 88003, USA.
authors.forename: Malika P
authors.initials: MP
authors.lastname: Godamudunage
authors.affiliation: Diné College Main Campus, Tsaile, AZ, USA.
authors.forename: Albert
authors.initials: A
authors.lastname: Foster
authors.affiliation: San Juan College, Farmington, NM, USA.
authors.forename: Darius
authors.identifier: 0000-0003-2862-3982
authors.initials: D
authors.lastname: Warren
authors.affiliation: Department of Chemistry and Biochemistry, New Mexico State University, Las Cruces, NM, 88003, USA.
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Lyons
mesh_terms: D001665:Binding Sites; D003001:Cloning, Molecular; D003432:Cross-Linking Reagents / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D051382:GRB7 Adaptor Protein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D005822:Genetic Vectors / Q000737:chemistry / Q000378:metabolism; D005976:Glutaral / Q000737:chemistry*; D005982:Glutathione Transferase / Q000235:genetics / Q000378:metabolism; D006639:Histidine / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008958:Models, Molecular; D009842:Oligopeptides / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D000072756:Protein Conformation, alpha-Helical; D000072757:Protein Conformation, beta-Strand; D054730:Protein Interaction Domains and Motifs; D055503:Protein Multimerization; D011993:Recombinant Fusion Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D040681:Structural Homology, Protein; D013816:Thermodynamics
chemical_list: D003432:Cross-Linking Reagents; C495955:GRB7 protein, human; C471213:His-His-His-His-His-His; D009842:Oligopeptides; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D051382:GRB7 Adaptor Protein; D006639:Histidine; D005982:Glutathione Transferase; D005976:Glutaral
keywords: Grb7; RAPH domains; cancer; cell migration; oligomerization