In insects,20-hydroxyecdysone(20E)limits systemic growth by triggering developmental transitions.Previous studies have shown that 20E-induced let-7 exhibits crosstalk with the cell cycle.Here,we examined the underlyin...In insects,20-hydroxyecdysone(20E)limits systemic growth by triggering developmental transitions.Previous studies have shown that 20E-induced let-7 exhibits crosstalk with the cell cycle.Here,we examined the underlying molecular mechanisms and physiological functions of 20E-induced let-7 in the fat body,an organ for energy storage and nutrient mobilization which plays a critical role in the larval growth.First,the overexpression of let-7 decreased the body size and led to the reduction of both nucleolus and cell sizes in the larval fat body.In contrast,the overexpression of let-7-Sponge increased the nucleolus and cell sizes.Moreover,we found that cdc7,encoding a conserved protein kinase that controls the endocycle,is a target of let-7.Notably,the mutation of cdc7 in the fat body resulted in growth defects.Overall,our findings revealed a novel role of let-7 in the control of endoreduplication-related growth during larval-prepupal transition in Drosophila.展开更多
To the Editor:Kinase cell division cycle 7(CDC7),a cell division cycle protein,takes a vital role in mediating DNA replication1.CDC7 complexes in the nucleus can phosphorylate the minichromosome maintenance complex(MC...To the Editor:Kinase cell division cycle 7(CDC7),a cell division cycle protein,takes a vital role in mediating DNA replication1.CDC7 complexes in the nucleus can phosphorylate the minichromosome maintenance complex(MCM)family members that bind to chromosomes.In addition,CDC7 kinase,as a molecular switch regulating DNA replication,can mediate DNA damage signaling pathways to stimulate cell cycle termination as well as DNA replication2.Studies have shown that CDC7 is overexpressed in many types of cancer cells,and its overexpression was related to poor patient survival,tumor grade,genetic instability,aneuploidy and so on3.Therefore,CDC7 is a promising target for antitumor therapy.展开更多
基金supported by the National Science Foundation of China(31802010 and 31702054)to Xiao-Ling Xia and Suiting Liu,the Natural Science Foundation of Guangdong Province(2019A1515011899)to Su-Ning Liu.
文摘In insects,20-hydroxyecdysone(20E)limits systemic growth by triggering developmental transitions.Previous studies have shown that 20E-induced let-7 exhibits crosstalk with the cell cycle.Here,we examined the underlying molecular mechanisms and physiological functions of 20E-induced let-7 in the fat body,an organ for energy storage and nutrient mobilization which plays a critical role in the larval growth.First,the overexpression of let-7 decreased the body size and led to the reduction of both nucleolus and cell sizes in the larval fat body.In contrast,the overexpression of let-7-Sponge increased the nucleolus and cell sizes.Moreover,we found that cdc7,encoding a conserved protein kinase that controls the endocycle,is a target of let-7.Notably,the mutation of cdc7 in the fat body resulted in growth defects.Overall,our findings revealed a novel role of let-7 in the control of endoreduplication-related growth during larval-prepupal transition in Drosophila.
基金Zenji Research Laboratories for financial aid to this work
文摘To the Editor:Kinase cell division cycle 7(CDC7),a cell division cycle protein,takes a vital role in mediating DNA replication1.CDC7 complexes in the nucleus can phosphorylate the minichromosome maintenance complex(MCM)family members that bind to chromosomes.In addition,CDC7 kinase,as a molecular switch regulating DNA replication,can mediate DNA damage signaling pathways to stimulate cell cycle termination as well as DNA replication2.Studies have shown that CDC7 is overexpressed in many types of cancer cells,and its overexpression was related to poor patient survival,tumor grade,genetic instability,aneuploidy and so on3.Therefore,CDC7 is a promising target for antitumor therapy.
