Department of Tropical Medicine and Infectious Disease, Vector-Borne Infectious Disease Research Center, School of Public Health and Tropical Medicine, Tulane University, New Orleans, LA, 70112, USA.
Department of Entomology, The University of Arizona, Tucson, AZ, 85721, USA.
Insect Biochem Mol Biol. 2023 Nov;162:104015. doi: 10.1016/j.ibmb.2023.104015. Epub 2023 Oct 4.
We previously demonstrated that Aedes aegypti pyruvate kinase (AaPK) plays a key role in the regulation of both carbon and nitrogen metabolism in mosquitoes. To further elucidate whether AaPK can be post-translationally regulated by Ae. aegypti sirtuin 2 (AaSirt2), an NAD-dependent deacetylase that catalyzes the removal of acetyl groups from acetylated lysine residues, we conducted a series of analysis in non-starved and starved female mosquitoes. Transcriptional and protein profiles of AaSirt2, analyzed by qPCR and western blots, indicated that the AaSirt2 is differentially modulated in response to sugar or blood feeding in mosquito tissues dissected at different times during the first gonotrophic cycle. We also found that AaSirt2 is localized in both cytosolic and mitochondrial cellular compartments of fat body and thorax. Multiple lysine-acetylated proteins were detected by western blotting in both cellular compartments. Furthermore, western blotting of immunoprecipitated proteins provided evidence that AaPK is lysine-acetylated and bound with AaSirt2 in the cytosolic fractions of fat body and thorax from non-starved and starved females. In correlation with these results, we also discovered that RNAi-mediated knockdown of AaSirt2 in the fat body of starved females significantly decreased AaPK protein abundance. Notably, survivorship of AaSirt2-deficient females maintained under four different nutritional regimens was not significantly affected. Taken together, our data reveal that AaPK is post-translationally regulated by AaSirt2.
我们之前证明了埃及伊蚊丙酮酸激酶（AaPK）在蚊子的碳氮代谢调节中起着关键作用。为了进一步阐明 Ae. aegypti sirtuin 2（AaSirt2）是否可以对 AaPK 进行翻译后调控，AaSirt2 是一种 NAD 依赖性去乙酰化酶，可催化乙酰化赖氨酸残基上的乙酰基去除，我们在非饥饿和饥饿的雌性蚊子中进行了一系列分析。通过 qPCR 和 Western blot 分析的 AaSirt2 的转录和蛋白谱表明，AaSirt2 在蚊子组织中对糖或血液摄入的反应在第一个生殖周期的不同时间被不同地调节。我们还发现 AaSirt2 定位于脂肪体和胸部的细胞质和线粒体细胞区室中。Western blot 在两个细胞区室中检测到多种赖氨酸乙酰化蛋白。此外，免疫沉淀蛋白的 Western blot 提供了证据表明 AaPK 在非饥饿和饥饿雌性的脂肪体和胸部的细胞质部分中被赖氨酸乙酰化，并与 AaSirt2 结合。与这些结果相关，我们还发现饥饿雌性脂肪体中的 AaSirt2 的 RNAi 介导的敲低显著降低了 AaPK 蛋白丰度。值得注意的是，在四种不同营养方案下维持的 AaSirt2 缺陷雌性的存活率没有受到显著影响。总之，我们的数据表明 AaPK 受 AaSirt2 的翻译后调控。
