Research
| Title： | Glutamate boosts IMP production in triploid crucian carp muscle via phosphoribosyl pyrophosphate amido transferase and ATP pathways |
|---|---|
| First author： | Zuo, Anli; Zheng, Qianting; Zhao, Dafang; Zhao, Junchi; He, Yimiao; Tang, Jianzhou; Zhou, Yonghua; Jin, Junyan; Cao, Shenping; Liu, Zhen |
| Journal： | AQUACULTURE |
| Years： | 2025 |
| DOI： | 10.1016/j.aquaculture.2025.742346 |
| Abstract： | Inosine monophosphate (IMP) plays a crucial role in promoting umami characteristic of fish muscle. Here, we investigated the contributions of Glutamate (Glu) to the formation of IMP in the muscle of Triploid Crucian Carp (TCC) (Carassius auratus) and the underlying molecular mechanisms. Through supplementary 0.5 % and 3 % Glu in diets and 2 mg/mL Glu in muscle precursor cells of TCC, we initially observed a significant elevation of IMP content and the mRNA expression of phosphoribosyl pyrophosphate amido transferase (ppat) both in vivo and in vitro (P < 0.05). By transcriptome analysis of the TCC muscle precursor cells, 2 mg/mL Glu was found to activate the IMP biosynthetic pathways (P < 0.05). Subsequently, we successfully cloned the ppat cDNA from TCC. Sequence analysis revealed that the ppat mRNA sequence in TCC was 1521 bp, encoding 506 amino acids. Molecular docking analysis suggested a potential for interaction between glutamine (Gln) and PPAT protein in TCC. Furthermore, the PPAT interference experiment indicated that the capacity of Glu to enhance IMP formation was compromised, and Glu was unable to activate the gene expression involved in the IMP de novo synthesis pathway (adsl, paics, npr) in PPAT knockdown cells. In addition, we found that 2 mg/mL Glu facilitates increased ATP production through its conversion into alpha-Ketoglutaric acid (alpha-KG) (P < 0.05), subsequently promoting the formation of IMP independently of ppat activation in TCC muscle precursor cells. In summary, the study indicated that Glu supplementation enhances IMP formation in TCC muscle and muscle precursor cells, which attributed to not necessarily only activation of the PPAT-mediated IMP de novo synthesis pathway but also elevation of mitochondria-derived ATP production. These findings provide significant implications for the application of amino acid feed additives in aquaculture. |
