Monoclonal antibody production for coiled-coil domain containing-124 (CCDC-124) and its molecular characterization

Coiled-coil-domain-containing-124 (CCDC-124) is a novel protein of unknown function. The Ccdc-124 gene is highly conserved among eukaryotic species and is predicted to encode a 223 amino acids long protein. Yeast-two-hybrid assays had shown that CCDC-124 interacts with RasGEF1B guanine exchange factor, which was previously identified as a specific guanine exchange factor for Rap2, a member of the Rap subfamily of Ras-like G-proteins. In order to reveal the cellular function of CCDC-124 protein, different biochemical experiments, including Western Blotting and Sub-cellular localization studies were performed. In those experiments, a polyclonal antibody against an N-terminal peptide of CCDC-124 was used. Nevertheless, due to its polyclonal nature this antibody exhibited non-specific binding. Although it was determined that the gene encodes a 33 kDa protein and that the protein has diffused cytoplasmic localization, the results were not precise. In order to detect the protein more accurately, monoclonal antibodies were generated against CCDC-124. Throughout the project, mice were injected with pure HisTagged CCDC-124 protein. Via hybridoma technology antibodies were generated and selected for their recognition capacities. At the end, 3 positive hybridoma clones were produced: 7F7, 15C11 and 4B3. To characterize the produced monoclonal antibodies, Western Blot experiments were performed and their binding properties were compared to the polyclonal antibody. Among the three monoclones, 4B3 gave the most promising results at 33 kDa, in Western Blotting. The antibodies will be used in the determination of the protein's sub-cellular localization and in the analysis of its response to extracellular signals. These in turn will aid further analyses related to the protein's role within the cell.