Godamudunage Malika P, Foster Albert, Warren Darius, Lyons Barbara A
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.
J Mol Recognit. 2017 Aug;30(8). doi: 10.1002/jmr.2620. Epub 2017 Mar 14.
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.
生长因子受体结合蛋白7（Grb7）是一种衔接蛋白，在20%至30%的乳腺癌患者中，它常与成红细胞增多症致癌基因B 2受体共同扩增。Grb7的过表达与细胞迁移增加和癌症转移有关。据报道，Grb7的ras关联和普列克底物蛋白同源结构域区域可与其他各种下游信号蛋白相互作用，如四半Lin11、Isl-1、Mec-3（LIM）结构域异构体2和细丝蛋白α。这些相互作用被认为在调节Grb7介导的细胞迁移功能中发挥作用。全长Grb7蛋白已被证明可形成二聚体，并且对Grb7 SH2结构域的寡聚状态进行了广泛研究；然而，ras关联和普列克底物蛋白同源结构域的寡聚状态以及这种寡聚化在Grb7功能中的重要性尚未完全明确。在本研究中，我们使用尺寸排阻色谱、核磁共振、核弛豫研究、戊二醛交联和动态光散射来表征Grb7 RA结构域的寡聚状态。我们报告Grb7 RA结构域可以以瞬时多聚体形式存在，并根据建模结果推测Grb7 RA结构域寡聚化在Grb7功能中的潜在作用。
