Muscle type difference in the regulation of UCP3 under cold conditions.
We found opposite regulation of uncoupling protein 3 (UCP3) in slow-twitch soleus and fast-twitch gastrocnemius muscles of rats during cold exposure. Namely, the UCP3 mRNA level was downregulated in the soleus muscles, but upregulated in the gastrocnemius muscles after a 24-h cold exposure. In the analysis of UCP3 protein, we first succeeded in detecting UCP3 short-form as well as the long-form in vivo, which levels were decreased markedly in the cold-exposed soleus muscles. However, the levels of UCP3 and cytochrome oxidase subunit IV were well maintained in the cold-exposed gastrocnemius muscles with a rise in the total mitochondrial protein level, suggesting an increase of total oxidative ability. The fast-twitch muscle rather than the slow-twitch one may play an important role in adaptive responses, including thermogenesis under acute cold exposure.
Department of Molecular Genetics, National Institute for Longevity Sciences, 36-3 Gengo, Morioka-cho, Obu-shi, Aichi-ken 474-8522, Japan.
Zuocheng
Z
Wang
Yasuhide
Y
Kontani
Yuzo
Y
Sato
Takafumi
T
Mizuno
Nozomu
N
Mori
Hitoshi
H
Yamashita
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D003080:Cold Temperature; D015536:Down-Regulation; D005786:Gene Expression Regulation; D007473:Ion Channels; D008297:Male; D024101:Mitochondrial Proteins; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism*; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000378:metabolism; D009928:Organ Specificity; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D000071247:Uncoupling Protein 3
D002352:Carrier Proteins; D007473:Ion Channels; D024101:Mitochondrial Proteins; D020033:Protein Isoforms; D012333:RNA, Messenger; C000604394:Ucp3 protein, rat; D000071247:Uncoupling Protein 3