Monoclonal antibodies against human Tudor-SN.

Tudor-SN is a multifunctional regulator of gene expression that has been shown to function as a transcriptional co-activator, regulator of miRNA processing, mRNA splicing, and stability. Tudor-SN has also been identified as a component in RNA-induced silencing complex. Here we have produced and characterized seven monoclonal antibody (MAb) clones against human Tudor-SN. Antibodies were generated against the fourth staphylococcal nuclease-like domain (SN4) and the Tudor domain of human Tudor-SN. The MAbs recognize the Tudor-SN protein in Western blot analysis and immunoprecipitation, and detect the specific antigen in immunohistochemistry assays. One of the antibody clones also recognizes the Drosophila melanogaster and Danio rerio Tudor-SN. Immunocytochemistry of HeLa cells revealed Tudor-SN localization in nucleolus, suggesting a possible new function for the protein in the compartment. An extensive expression analysis in human tissue arrays shows moderate to high expression of Tudor-SN in a wide range of organs and tissues, especially in epithelial cell types.