MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China.
MOE Key Laboratory of Marine Genetics and Breeding, College of Marine Life Sciences, Ocean University of China, 5 Yushan Road, Qingdao 266003, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
Gene. 2025 Jan 15;933:148922. doi: 10.1016/j.gene.2024.148922. Epub 2024 Sep 5.
AMPK is a key regulator of metabolism in eukaryotes across various pathways related to energy regulation. Although extensive investigations of AMPK have been conducted in mammals and some model organisms, research on AMPK in scallops is comparatively limited. In this study, three AMPK family genes (AiAMPKα, AiAMPKβ and AiAMPKγ) in scallop Argopecten irradians irradians were identified through genome scanning. Structure prediction and phylogenetic analyses of AiAMPKs were performed to determine their structural features and evolutionary relationships. Spatiotemporal expression patterns of AiAMPKs at different developmental stages and in healthy adult tissues were analyzed to elucidate the function of AiAMPKs in bay scallops' growth and development. The spatiotemporally specific expression of AiAMPKs implied their important roles in growth and development of bay scallops. Heat stress experiment was performed to determine the regulations of AiAMPKs in four kinds of thermosensitive tissues. Expression profiles revealed distinct molecular mechanisms of AiAMPKs in different tissues in response to heat stress: significant down-regulations in mobile hemocytes, but dominant up-regulations occurring in stationary gills, mantles and hearts. Functional verification including knock-down of AiAMPKα and inhibition of AiAMPK was separately conducted in the thermotolerant tissue heart at the post-transcription and translation levels. The thermotolerant index Arrhenius break temperature (ABT) showed a significant decrease and the rate-amplitude product (RAP) peaked earlier in the individuals after RNAi targeting AiAMPKα, displaying an earlier transition to anaerobic metabolism under heat stress, indicating an impairing ability of aerobic metabolism. After AiAMPK inhibition, widespread down-regulations of genes in key energy metabolism pathways, RNA polymerase II-mediated transcription, and aminoacyl-tRNA synthesis pathways were obviously observed, revealing the post-translational inhibition of AiAMPK hindered cardiac energy metabolism, basal transcription and translation. Overall, our findings provide evidences for exploring the molecular mechanisms of energy regulation in thermotolerant traits in bay scallops under ongoing global warming.
AMPK 是真核生物中各种与能量调节相关途径的关键代谢调节剂。虽然哺乳动物和一些模式生物的 AMPK 已经进行了广泛的研究，但扇贝 AMPK 的研究相对较少。在本研究中，通过基因组扫描鉴定了海湾扇贝 Argopecten irradians irradians 中的三个 AMPK 家族基因（AiAMPKα、AiAMPKβ 和 AiAMPKγ）。对 AiAMPKs 的结构预测和系统发育分析表明了它们的结构特征和进化关系。分析了 AiAMPKs 在不同发育阶段和健康成年组织中的时空表达模式，以阐明 AiAMPKs 在海湾扇贝生长发育中的功能。AiAMPKs 的时空特异性表达表明它们在海湾扇贝生长发育中具有重要作用。进行了热应激实验，以确定 AiAMPKs 在四种热敏组织中的调节作用。表达谱揭示了 AiAMPKs 在不同组织中对热应激的不同分子机制：移动血细胞中显著下调，但在固定鳃、套膜和心脏中显著上调。在耐热组织心脏中分别进行了 AiAMPKα 的敲低和 AiAMPK 的抑制的功能验证，分别在转录后和翻译水平上进行。耐热指数 Arrhenius 断裂温度 (ABT) 在靶向 AiAMPKα 的 RNAi 个体中显著降低，速率-幅度产物 (RAP) 更早达到峰值，表明在热应激下更早地过渡到无氧代谢，表明有氧代谢能力受损。抑制 AiAMPK 后，关键能量代谢途径、RNA 聚合酶 II 介导的转录和氨酰-tRNA 合成途径中的基因广泛下调，表明 AiAMPK 的翻译后抑制阻碍了心脏能量代谢、基础转录和翻译。总的来说，我们的研究结果为探索在全球变暖背景下海湾扇贝耐热特性的能量调节分子机制提供了证据。
