Partial molecular cloning, characterization, and analysis of the subcellular localization and expression patterns of the porcine OTUB1 gene.

The product of the OTUB1 gene is a member of the OTU superfamily of predicted cysteine proteases and inhibits cytokine gene transcription via its interaction with a ubiquitin protease and E3 ubiquitin ligase. To further understand the functions of the porcine OTUB1 gene, the subcellular localization of porcine OTUB1 protein was analyzed. We first cloned a partial DNA sequence of porcine OTUB1 which contained an 816 bp ORF encoding 271 amino acids. The deduced protein product was found to contain an OTU domain. The corresponding porcine OTUB1 protein was subsequently demonstrated to localize predominantly in the nucleus by confocal fluorescence microscopy. By spatial expression analysis, we further found that OTUB1 is highly expressed in the brain, liver, spleen, lung, kidney, large intestine, small intestine, stomach, ovary, uterus and thymus. In contrast, only low levels of this gene were evident in the heart, dorsal muscles and leg muscle of the pig. This is the first report to show the subcellular localization of porcine OTUB1, and our current data provides us with an important basis for conducting further studies on the functions and regulatory mechanisms underlying the role of OTUB1 gene in the immune system.