AMP-activated protein kinase alpha 1 in Megalobrama amblycephala: Molecular characterization and the transcriptional modulation by nutrient restriction and glucose and insulin loadings

作者：Xu, Chao; Li, Xiang-Fei; Shi, Hua-Juan; Liu, Jie; Zhang, Li; Liu, Wen-Bin^*

来源：General and Comparative Endocrinology, 2018, 267: 66-75.

DOI：10.1016/j.ygcen.2018.05.030

• AMP-activated protein kinase alpha 1
• Gene cloning
• Transcriptional analysis
• Glucose metabolism
• Megalobrama amblycephala

This study aimed to characterize the full-length cDNA of AMP-activated protein kinase alpha 1 (AMPK alpha 1) from Megalobrama amblycephala and investigate the transcriptional response of this kinase to nutrient restriction and glucose and insulin loadings. The cDNA obtained was 3545-bp long with an open reading frame of 1710 bp encoding 570 amino acids. Multiple alignments and phylogenetic analyses revealed a high degree of conservation (80-100%) among most fish, retaining one kinase domain (KD), one auto-inhibitory domain (AID), one C-terminal domain (alpha-CTD), one regulatory-subunit-interacting motif (alpha-RIM), one serine/threonine-rich loop (ST loop), one alpha-hook, and several phosphorylation sites. AMPK alpha 1 mRNA was predominantly expressed in white muscle, gill, and brain tissues, whereas little was expressed in the intestines. After a fasting-refeeding phosphorylation and mRNA levels of AMPK alpha 1 were significantly greater in fish fasted for 10 days, while in re-fed fish at 1 h after re-feeding, the levels of this kinase were intermediate between those of the fish in the fed and fasted groups. Further, AMPK alpha 1 mRNA levels were quantified in the liver and muscle tissues of fish injected intraperitoneally with 1.67 g glucose per kg body weight and 0.052 mg insulin per kg body weight, respectively. Glucose and insulin administration resulted in a significant decrease in AMPK alpha 1 expression in both tissues with minimum values attained at 2 h and 4 h after injection, respectively. Thereafter, the expression increased significantly to the basal value at 24 h after injection, except in the liver in which the maximum value was obtained at 12 h post-glucose injection. Overall, AMPK alpha 1 of M. amblycephala was similar to that of other vertebrates, and nutrient restriction modified its phosphorylation and mRNA levels in liver and muscle tissues. Furthermore, substantial expression of this kinase was induced in both liver and muscle tissues by glucose and insulin administration.

• 出版日期2018-10-1
• 单位南京农业大学