Developmental regulation of rat Ubc13 and Uev1B genes in the nervous system

Ubiquitin is a highly conserved protein in eukaryotes, and regulates diverse cellular processes. Lys-63-linked poly-ubiquitination has been recently identified to be involved in non-proteolytic processes such as DNA repair and cytokine-mediated signal transduction. Although, the heterodimeric enzymes Ubc13 and Uev are required for ubiquitination, their expressional regulation is not known. We have analyzed changes in their expression during brain development. Northern blot analysis revealed that the expression levels of the two genes were very similar. Expression of both genes decreased gradually during the embryonic stages, then increased in the late postnatal period and was moderate in the adult. In situ hybridization analyses revealed that the expression patterns of the two genes were similar. Expression was observed in various regions in the embryonic brain but became restricted to specific regions after birth. In the adult, their expression was similar in regions such as the cerebral cortex, hippocampus, and substantia nigra, but different in the cerebellum. These results suggest that Ubc13 may be closely associated with Uev1B.