AUTHOR=Zhideng Lin , Jinjie Lan , Huangbin Lin , Chaoyang Huang , Mingyao Zhang , Qincheng Huang 

TITLE=Molecular cloning, tissue distribution and nutritional regulation of four acyl-coenzyme A oxidase (acox) isoforms in Scylla paramamosain

JOURNAL=Frontiers in Marine Science

VOLUME=11

YEAR=2024

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2024.1442810

DOI=10.3389/fmars.2024.1442810

ISSN=2296-7745

ABSTRACT=<p>As rate-limiting enzymes of peroxisomal β-oxidation, acyl-coenzyme A oxidase (ACOXs) play vital roles in maintaining energy homeostasis and regulating reactive oxygen species (ROS) metabolism. However, there are no studies on the functions of ACOXs in crustaceans. In the present study, four full-length cDNA sequences of <italic>acoxs</italic>, namely the <italic>acox-1a</italic> (2403 bp), <italic>acox-1b</italic> (2733 bp), <italic>acox-3a</italic> (2878 bp) and <italic>acox-3b</italic> (3445 bp), were successfully isolated from mud crab <italic>Scylla paramamosain</italic>, which encoded 666, 673, 701 and 658 amino acids, respectively. Sequence analysis showed that the ACOX-1a, ACOX-1b and ACOX-3a possessed conserved structural domains like FAD-binding motif, fatty acyl CoA oxidase domain and peroxisomal targeting signal, while the ACOX-3b lacked peroxisomal targeting signal. Results of phylogenetic tree indicated that the four ACOXs of mud crab grouped gathered with their corresponding orthologues from crustaceans. The <italic>acox-1a</italic>, <italic>acox-3a</italic> and <italic>acox-3b</italic> were highly expressed in hepatopancreas, and the <italic>acox-1b</italic> was mainly distributed in muscle and hepatopancreas. Compared with feeding groups, the expression levels of <italic>acox-1a</italic>, <italic>acox-3a</italic> and <italic>acox-3b</italic> in hepatopancreas and <italic>acox-3a</italic> in muscle were markedly up-regulated in fasting groups, suggesting that the <italic>acoxs</italic> had significant effects in modulating energy balance during fasting. In addition, fasting significantly increased the transcriptional levels of nuclear factor erythroid 2-related factor (<italic>nrf2</italic>) and its downstream antioxidant genes (catalase (<italic>cat</italic>), glutathione peroxidase (<italic>gpx</italic>) and glutathione S-transferase (<italic>gst</italic>)) to improve antioxidant capacity for removing excessive ROS produced by ACOX-mediated peroxisomal β-oxidation. These results would be conducive to providing new insights into evolutionary characteristics and functions of <italic>acoxs</italic> in crustaceans.</p>