Nutrition regulates the expression of storage proteins in Bombyx mori via insulin-like/FoxO signaling pathway
Nutrition regulates the expression of storage proteins in Bombyx mori via insulin-like/FoxO signaling pathway
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营养通过类胰岛素/FoxO信号通路调节家蚕储存蛋白的表达
DOI：
10.1016/j.ibmb.2022.103847
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发表时间：
2022
影响因子：
3.8
通讯作者：
Yong Hou
中科院分区：
文献类型：
--
作者：
Jiamin Yan;Zhao Xue;Haonan Dong;Jiaxin Pang;Huawei Liu;Jing Gong;Qingyou Xia;Yong Hou
昆虫血清蛋白（Insect serum proteins），又称贮藏蛋白（Storage proteins，SP），是一种六聚体蛋白，在大多数昆虫的蛹和胚胎发育过程中起重要作用。本研究对家蚕SP基因的表达及其调控途径进行了研究。我们观察到B.饥饿显著降低了脂肪体中的桑色素（BmSPs）含量，表明桑色素对营养缺乏有反应。此外，我们还检测了BmSP表达与胰岛素样信号通路（ILS）之间的关系，以研究BmSP表达的调控。结果表明，胰岛素可上调BmSPs的表达，而ILS途径蛋白PI 3 K的抑制剂可下调BmSPs的表达。桑幼虫在体外培养的脂肪体和BmE细胞中观察到类似的结果。然后，我们在BmE细胞和B中过表达FoxO，一种ILS转录因子。进一步验证了ILS对BmSPs表达的调控作用，发现BmFoxO对BmE细胞和家蚕幼虫BmSPs的表达都有负调控作用。此外，BmFoxO的去磷酸化，并从细胞质转移到细胞核饥饿处理。最后，在BmSP 1转录起始位点上游的-2627-2644 bp处的元件通过电泳迁移率变动分析被鉴定为BmFoxO的结合位点，并通过染色质免疫沉淀验证。总之，我们的研究结果表明，营养吸收触发BmSPs的表达通过ILS/FoxO信号通路。本研究为进一步研究昆虫SP基因的表达调控提供了参考。·饥饿降低了家蚕中贮藏蛋白（SP）的表达。·胰岛素样信号调节家蚕幼虫细胞和脂肪体中SP的表达。·BmFoxO的过表达在体外和体内均降低SP表达。·BmSPl启动子上游的元件结合BmFoxO。
Insect serum proteins , also termed storage proteins (SPs), are hexamer proteins that form amino acid reservoirs important for the development of pupae and embryos in most insects. In this study, we investigated the SP genes expression and regulation pathways in silkworms ( Bombyx mori ). We observed that B. mori SPs (BmSPs) in the fat body of larvae were strongly decreased by starvation, suggesting they respond to nutrition deprivation. Further, we examined the relationship between BmSP expression and the insulin-like signaling pathway (ILS) to study the regulation of BmSPs expression. The results showed that insulin up-regulated the expression of BmSPs, but an inhibitor of the ILS pathway protein PI3K downregulated the expression of BmSPs in B. mori larvae. Similar results were observed in cultured fat body in vitro and BmE cells. We then over-expressed FoxO, an ILS transcriptional factor, in BmE cells and B. mori larvae to further verify the regulatory role of ILS on expression of BmSPs and found BmFoxO negatively regulates the expression of BmSPs in both BmE cells and larvae. Moreover, BmFoxO was dephosphorylated and translocated from the cytoplasm to the nucleus under starvation treatment. Finally, an element on −2627–2644 bp upstream of the transcription start site of BmSP1 was identified as the binding site of BmFoxO by electrophoretic mobility shift assay and verified by chromatin immunoprecipitation. In summary, our results indicate that nutrient uptake triggers the expression of BmSPs via the ILS/FoxO signaling pathway. This study provides a reference for further study on the expression and regulation of insect SP genes. • Starvation lowers expression of storage proteins (SPs) in silkworms. • Insulin-like signaling regulates SP expression in larval silkworm cells and fat body. • Overexpression of BmFoxO reduces SP expression both in vitro and in vivo. • An element upstream of a BmSP1 promoter binds BmFoxO.