SUMO-1 immunoreactivity co-localizes with phospho-Tau in APP transgenic mice but not in mutant Tau transgenic mice.

Sumoylation is a post-translational modification process that is supposed to be implicated in the pathogenesis of several neurodegenerative diseases. Recently, the microtubule-associated protein Tau was identified as a target for sumoylation in the analysis of the transfected cells. We investigated the localization of SUMO-1 protein in APP transgenic mice and mutant Tau transgenic mice, and found that SUMO-1 immunoreactivity was co-localized with phosphorylated Tau aggregates in amyloid plaques of APP transgenic mice. By contrast, no SUMO-1 immunoreactivity was observed in phosphorylated Tau aggregates of mutant Tau transgenic mice. The contribution of sumoylation to the neurodegeneration in Alzheimer's disease will be further elucidated via the analysis of APP transgenics.