Development of Polyclonal Antibodies for the Preliminary Characterization of GPATCH1, a Novel Splicing Factor Associated with Human Osteoporosis.

Specific antibodies, which can be used in various experiments, are critical tools for unraveling genes' function, but many commercial antibodies are not tested for these properties. GPATCH1 is a novel G-patch family protein. Genome-wide association studies (GWAS) revealed it as a gene associated with human osteoporosis, and yeast-based research suggested it may be a splicing factor; however, its molecular mechanism remains a mystery. We report here that currently available commercial GPATCH1 antibodies have poor specificity and are not recommended for immunoprecipitation. We elucidated the apparent molecular weight of GPATCH1 to evaluate the antibodies' specificity. Based on this, a specific polyclonal antibody against GPATCH1 that can be used for Western blotting, immunoprecipitation and immunofluorescence was prepared. With the antibodies, we found that GPATCH1 may be a tissue-specific splicing factor. Our study lays the groundwork for further investigations into the molecular mechanisms by which GPATCH1 affects bone metabolism in the future.