Glutaminase 1 in mandarin fish Siniperca chuatsi: Molecular characterization, expression pattern and function involving in virus replication.

Glutaminolysis plays a critical role in viral replication. While Glutaminase 1 (GLS1) is a key enzyme in the glutaminolysis pathway. However the characteristic and function of GLS1 in mandarin fish during viral infection remains largely unknown. In the present study, the full-length cDNA of GLS1, designated as Sc-GLS1, was cloned from mandarin fish (Siniperca chuatsi) with an open-reading frame of 1920 bp, and encoded a 639 amino acid polypeptide with 5′ and 3′ untranslated regions of 115 and 1287 bp, respectively. Multiple alignment of the amino acid sequence showed that Sc-GLS1 shared high identities with other homologues from different species. Sc-GLS1 protein has the typical conserved domains including the glutaminase domain and the ankyrin domain. Quantitative real-time PCR (qPCR) assay revealed that Sc-GLS1 was ubiquitously expressed in all tissues examined, and it was most abundant in the hind kidney. In addition, mRNA and protein level of Sc-GLS1 was significantly up-regulated with a biphasic expression pattern in the Chinese perch brain (CPB) cell line and the spleen of mandarin fish post infection by infectious kidney and spleen necrosis virus (ISKNV). And Sc-GLS1 expression in mRNA and protein level was also significantly up-regulated in CPB cells and the spleen of mandarin fish post infection by Siniperca chuatsi rhabdovirus (SCRV). After knocking down Sc-GLS1 with siRNA or inhibiting Sc-GLS1 activity with BPTES, protein expression and yields of ISKNV and SCRV were significantly decreased determined by western blotting and qPCR. These findings provided more information of GLS1 for further insight into virus-induced host metabolism alteration. • GLS1 cDNA of mandarin fish (Siniperca chuatsi) (Sc-GLS1) was cloned and characterized. • Sc-GLS1 mRNA and protein expression was up-regulated after ISKNV or SCRV infection. • Inhibiting Sc-GLS expression and activity decreased ISKNV and SCRV yield. [ABSTRACT FROM AUTHOR]