Protein expression of ubiquitin in interscapular brown adipose tissue during acclimation of rats to cold: the impact of (∙)NO.

In this study, the effects of L-arginine-nitric-oxide ((∙)NO)-producing pathway on protein content of ubiquitin, as an important component of ubiquitin-proteasome system for protein removal, were investigated. We showed that L-arginine markedly decreased ubiquitin protein content in interscapular brown adipose tissue, both in thermogenic inactive (at room temperature) and thermogenic active (on cold) states; while in L-NAME-treated groups this effect was abolished. This result suggests that nitric oxide ((∙)NO), besides well established roles, is involved in this aspect of structure remodeling, as well.