AMP-activated protein kinase regulates circadian rhythm by affecting CLOCK in Drosophila

• DOI: 10.1523/jneurosci.2344-18.2019
• Publication Date: 2019-02-28T22:45:14Z
• Authors: Eunjoo Cho; Miri Kwon; Jaewon Jung; Doo Hyun Kang; Sanghee Jin; Sung-E Choi; Yup Kang; Eun Young Kim
• Keywords: Male; Neurons; 0303 health sciences; CLOCK Proteins; Down-Regulation; AMP-Activated Protein Kinases; Circadian Rhythm; Protein Subunits; 03 medical and health sciences; Drosophila melanogaster; Gene Expression Regulation; Animals; Drosophila Proteins; Locomotion

The circadian clock organizes the physiology and behavior of organisms to their daily environmental rhythms. central timekeeping mechanism in eukaryotic cells is transcriptional-translational feedback loop (TTFL). In <i>Drosophila</i> TTFL, transcription factors CLOCK (CLK) CYCLE (CYC) play crucial roles activating expression core genes clock-controlled genes. Many signaling pathways converge on CLK/CYC complex regulate its activity fine-tune cellular oscillator time cues. We aimed identify that CLK by performing tandem affinity purification combined with mass spectrometry using S2 stably express HA/FLAG-tagged V5-tagged CYC. identified SNF4Aγ, a homolog mammalian AMP-activated protein kinase γ (AMPKγ), as factor copurified CLK. AMPK holoenzyme composed catalytic subunit AMPKα two regulatory subunits, AMPKβ AMPKγ, directly phosphorylated purified <i>in vitro</i>. Locomotor analysis revealed knockdown each pacemaker neurons induced arrhythmicity long periods. Knockdown reduced levels neurons, thereby pre-mRNA downstream genes, such <i>period</i> <i>vrille</i>. Finally, overexpression reversed long-period phenotype resulted from knockdown. Thus, we conclude AMPK, regulator energy metabolism, regulates stabilizing CLK/CYC-dependent transcription. <b>SIGNIFICANCE STATEMENT</b> Regulation CYC fundamental synchronize changes. Here, show AMPKγ copurifies cells. Furthermore, phosphorylates This study demonstrates CLK, which enhances mammals, affects downregulating repressor proteins. It intriguing note required for regulation through enhancement, whereas target action different mammals (positive vs negative element, respectively).