Laboratório Integrado de Bioquímica - Hatisaburo Masuda, Instituto de Biodiversidade e Sustentabilidade, NUPEM/UFRJ, Macaé, Brazil.
Instituto Nacional de Ciência e Tecnologia - Entomologia Molecular, UFRJ, Rio de Janeiro, Brazil.
Arch Insect Biochem Physiol. 2019 Dec;102(4):e21606. doi: 10.1002/arch.21606. Epub 2019 Sep 9.
Polyphosphates (polyPs) have been found in all cell types examined to date and play diverse roles, depending on the cell type. In eukaryotic organisms, polyPs have been mainly investigated in mammalian cells, with few studies on insects. In this study, we investigated mitochondrial polyphosphate metabolism in the red flour beetle, Tribolium castaneum. Substrate specificity for different chain lengths demonstrated the presence of two exopolyphosphatase isoforms in mitochondria. T. castaneum mitochondrial polyP levels decreased after injection with soluble pyrophosphatase (Tc-sPPase) dsRNA, while the membrane exopolyphosphate activity increased. Mitochondrial respiration modulated exopolyphosphatase activity only in wild-type beetles. Tripolyphosphate was able to increase the F-ATPase activity in wild-type and Tc-sPPase RNAi beetles. We suggest that inorganic pyrophosphatase modulates polyphosphate metabolism in mitochondria and affects the link between mitochondrial activity and polyphosphate metabolism in T. castaneum.
多聚磷酸盐（polyPs）已在迄今为止研究的所有细胞类型中被发现，并根据细胞类型发挥多样化的作用。在真核生物中，polyPs 主要在哺乳动物细胞中进行研究，而在昆虫中研究较少。在这项研究中，我们研究了红粉甲虫（Tribolium castaneum）中线粒体的多聚磷酸盐代谢。对不同链长的底物特异性表明线粒体中存在两种外切多聚磷酸酶同工酶。用可溶性焦磷酸酶（Tc-sPPase）dsRNA 注射后，T. castaneum 线粒体多聚磷酸盐水平下降，而膜外切多聚磷酸盐活性增加。线粒体呼吸仅在野生型甲虫中调节外切多聚磷酸酶活性。三聚磷酸盐能够增加野生型和 Tc-sPPase RNAi 甲虫的 F-ATP 酶活性。我们认为无机焦磷酸酶调节线粒体中的多聚磷酸盐代谢，并影响 T. castaneum 中线粒体活性和多聚磷酸盐代谢之间的联系。
