Vasquez M Christina, Beam Michelle, Blackwell Shelley, Zuzow Marcus J, Tomanek Lars
California Polytechnic State University, Department of Biological Sciences, Center for Coastal Marine Sciences, Environmental Proteomics Laboratory, 1 Grand Avenue, San Luis Obispo, CA 93407-0401, USA.
California Polytechnic State University, Department of Biological Sciences, Center for Coastal Marine Sciences, Environmental Proteomics Laboratory, 1 Grand Avenue, San Luis Obispo, CA 93407-0401, USA
J Exp Biol. 2017 Dec 1;220(Pt 23):4515-4534. doi: 10.1242/jeb.160325. Epub 2017 Oct 12.
The blue mussels and are competing species with biogeographical ranges set in part by environmental exposure to heat and hyposalinity. The underlying cellular mechanisms influencing interspecific differences in stress tolerance are unknown, but are believed to be under regulation by sirtuins, nicotinamide adenine dinucleotide (NAD)-dependent deacylases that play a critical role in the cellular stress response. A comparison of the proteomic responses of and to an acute heat shock in the presence and absence of the sirtuin inhibitor suramin (SIRT1, 2 and 5) showed that sirtuins affected molecular chaperones, oxidative stress proteins, metabolic enzymes, cytoskeletal and signaling proteins more in the heat-sensitive than in the heat-tolerant Interactions between sirtuin inhibition and changes in the abundance of proteins of β-oxidation and oxidative stress in suggest a greater role of sirtuins in shifting metabolism to reduce the production of reactive oxygen species near thermal limits. Furthermore, RNA-binding proteins initiating and inhibiting translation were affected by suramin in and , respectively. Western blot analysis showed that the levels of mitochondrial sirtuin 5 (SIRT5) were generally three times higher and increased with acute heat stress in response to sirtuin inhibition in but not in , suggesting a possible feedback response in the former species and a greater reliance on SIRT5 for its stress response. Our findings suggest that SIRT5 plays an important role in setting interspecific differences in stress tolerance in by affecting the stress proteome.
蓝贻贝是竞争物种，其生物地理分布范围部分由热暴露和低盐度环境决定。影响种间胁迫耐受性差异的潜在细胞机制尚不清楚，但据信受沉默调节蛋白调控，沉默调节蛋白是烟酰胺腺嘌呤二核苷酸（NAD）依赖性脱酰基酶，在细胞应激反应中起关键作用。在有和没有沉默调节蛋白抑制剂苏拉明（SIRT1、2和5）的情况下，比较蓝贻贝和紫贻贝对急性热休克的蛋白质组反应，结果表明，与耐热的紫贻贝相比，沉默调节蛋白对热敏感的蓝贻贝中分子伴侣、氧化应激蛋白、代谢酶、细胞骨架和信号蛋白的影响更大。在蓝贻贝中，沉默调节蛋白抑制与β-氧化和氧化应激蛋白丰度变化之间的相互作用表明，沉默调节蛋白在转变代谢以减少接近热极限时活性氧的产生方面发挥更大作用。此外，启动和抑制翻译的RNA结合蛋白分别受苏拉明在蓝贻贝和紫贻贝中的影响。蛋白质免疫印迹分析表明，线粒体沉默调节蛋白5（SIRT5）的水平通常高出三倍，并且在蓝贻贝中，随着急性热应激响应沉默调节蛋白抑制而增加，但在紫贻贝中没有增加，这表明在前一个物种中可能存在反馈反应，并且其应激反应对SIRT5的依赖性更大。我们的研究结果表明，SIRT5通过影响应激蛋白质组在设定蓝贻贝种间胁迫耐受性差异方面发挥重要作用。
