Translational Regulation of Clock Genes BMAL1 and REV-ERBα by Polyamines

Polyamines stimulate the synthesis of specific proteins at the level of translation, and the genes encoding these proteins are termed as the “polyamine modulon”. The circadian clock generates daily rhythms in mammalian physiology and behavior. We investigated the role of polyamines in the circadian...

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Bibliographic Details
Main Authors: Akihiko Sakamoto, Yusuke Terui, Takeshi Uemura, Kazuei Igarashi, Keiko Kashiwagi
Format: Article
Language:English
Published: MDPI AG 2021-01-01
Series:International Journal of Molecular Sciences
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Online Access:https://www.mdpi.com/1422-0067/22/3/1307
Description
Summary:Polyamines stimulate the synthesis of specific proteins at the level of translation, and the genes encoding these proteins are termed as the “polyamine modulon”. The circadian clock generates daily rhythms in mammalian physiology and behavior. We investigated the role of polyamines in the circadian rhythm using control and polyamine-reduced NIH3T3 cells. The intracellular polyamines exhibited a rhythm with a period of about 24 h. In the polyamine-reduced NIH3T3 cells, the circadian period of circadian clock genes was lengthened and the synthesis of BMAL1 and REV-ERBα was significantly reduced at the translation level. Thus, the mechanism of polyamine stimulation of these protein syntheses was analyzed using NIH3T3 cells transiently transfected with genes encoding enhanced green fluorescent protein (EGFP) fusion mRNA with normal or mutated 5′-untranslated region (5′-UTR) of <i>Bmal1</i> or <i>Rev-erbα</i> mRNA. It was found that polyamines stimulated BMAL1 and REV-ERBα synthesis through the enhancement of ribosomal shunting during the ribosome shunting within the 5′-UTR of mRNAs. Accordingly, the genes encoding <i>Bmal1</i> and <i>Rev-erbα</i> were identified as the members of “polyamine modulon”, and these two proteins are significantly involved in the circadian rhythm control.
ISSN:1661-6596
1422-0067