[대학원 생명과학과 세미나 안내] 

연사 : 김은영 교수(아주대학교 의과대학 뇌과학과)

연제 : Metabolic control of circadian rhythm in Drosophila

일시 : 2021년 10월 08일 (금) 오후 5시 

장소 : 온라인 화상 강의로 진행됩니다.

초청교수 : 백자현 교수

Abstract
 The circadian clock drives ∼24 hour (circadian) rhythms in behavior and physiology of organisms synchronizing to rhythmic changes of environment. The central circadian timekeeping mechanism in eukaryotic cells is the transcriptional-translational feedback loop (TTFL), which has been elucidated using Drosophila as a genetically trackable model system. 
 Firstly, I will give introduction about the circadian rhythm. The circadian clock system of animal is composed of master clock residing in the brain and the peripheral clocks that are present in nearly every tissue. Light signals and other time cues entrain the central circadian clock, which in turn synchronize the peripheral clocks via neuronal and endocrinal signal. When the master and peripheral clocks are in synchrony to environment, animals manifest healthy physiology. Molecularly, circadian clock operates in cell autonomous manner. Nobel Prize works of Michael Rosbash, Jeff Hall, and Mike Young using the fruitfly, Drosophila elucidated the basic molecular mechanism of circadian clock. In brief, transcriptional translational feedback loop (TTFL) composed of transcription factors and repressor proteins generate rhythmic transcription of core clock genes and clock controlled genes. 
 Although TTFLs constitute the overall architecture of circadian timing mechanisms, post-translational modifications of clock proteins are essential to generate 24-h rhythms. In the second part, I will talk about O-GlcNAc modification of PER and its role in circadian rhythm. OGT and OGA dependent O-GlcNAc modification of PER contributes to setting the correct pace of the clock by delaying the timing of PER nuclear entry. 
 While the most potent timing cue for circadian clock system is light, food also impact circadian clock system. Notably timed restricted feeding reset peipheral clocks and drive animal’s food-anticipatory activity. Food contents modulate rhythmic behaviors as well. Mice fed with a high fat diet exhibit activity with reduced rhythmicity and lengthened periods. In the last part of the talk, I will talk about daily locomotor behavior of Drosophila in high nutrient food and underlying neuropeptidergic control mechanism.