Anti-G3BP1 monoclonal antibody, clone 3G4

Background: Homer scaffolding protein 1 (Homer1) is a postsynaptic scaffold protein that regulates the structure and function of excitatory synaptic as well as its intracellular signal transduction. However, the role of Homer1 in colorectal cancer as well as the underlying molecular mechanisms has not been elucidated. Materials and Methods: To evaluate the alternations of gene expression during colorectal cancer, Homer1 expression was analyzed using the gene expression profiling interactive analysis and Oncomine analyses. The prognostic value of Homer1 expression was validated by our own colorectal cancer specimens using RT-PCR. Then, the cell viability, migration and invasion of colorectal cancer cell lines were detected by CCK-8 and transwell assay. Results: We obtained the following important results. (1) Homer1 expression was significantly higher in colorectal cancer than normal samples. (2) Among patients with colorectal cancer, those with higher Homer1 expression had a lower survival rate. (3) The major mutation type of Homer1 in colorectal cancer samples was missense mutation. (4) Homer1 was able to promote colorectal cancer cell proliferation, migration, and invasion through upregulating G3BP1 in vitro. Conclusion: Our findings suggest that Homer1 may play a role in malignancy of colorectal cancer mainly through the G3BP1 signaling pathway, which might be a potential indicator of poor prognosis.

Caprin-1 is an RNA-binding protein which plays critical roles in several important biological processes, including cellular proliferation, the interferon-mediated antiviral innate immune response, the maintenance of synaptic plasticity and the formation of RNA stress granules. Caprin-1 has been implicated in the pathogenesis of several human diseases, including osteosarcoma, breast cancer, viral infections, hearing loss and neurodegenerative disorders. Despite the emerging biological and physiopathological significance of Caprin-1, no structural information is available for this protein. Moreover, Caprin-1 does not have sequence similarity to any other protein with a known structure. It is therefore expected that structural studies will play a particularly crucial role in revealing the functional mechanisms of Caprin-1. Here, a protein fragment of human Caprin-1 consisting of residues 112-260 was expressed, purified and crystallized. Native and Se-SAD data sets were collected to resolutions to 2.05 and 2.65 angstrom, respectively, in different space groups.