Etermined protein expression of three ER-resident selenoproteins. Our study identified that, compared with the A-Se diet regime, the M-Se diet program lowered the protein expression of Raf Formulation SELENOM and SELENOS, plus the E-Se eating plan escalated the protein expression of SELENOM, mGluR7 Accession SELENOS and SELENON. Inside the ER lumen, SELENOM is really a thiol-disulfide oxidoreductase and includes an active web site consisting of a Sec-containing thioredoxin-like motif and an ER retention tetrapeptide in the C-terminal domain. [16]. SELENON has indispensable roles in calcium homeostasis regulation [59]. SELENOS is closely linked with oxidative pressure, ER stress, plus the regulation of lipid metabolism [13,60]. Zhao et al. reported that higher Se did not affect the proteins expression of muscle SELENOS in pigs [8]. In contrast, Zhao et al. reported that dietary Se supplementation enhanced the protein expression of SELENOS inside the spleen on the chick [36]. Therefore, the ER-resident selenoproteins mediated dietary Se deficiency- and excess-induced ER strain, and also the up-regulation of their expression helped to suppress ER anxiety, which protected the cells against the harm by ER anxiety. As a result, it could be plausible to assume that these 3 ER-resident selenoproteins mediated M-Se- and E-Se-induced changes of ER strain. Additionally, we located that the protein expression of SELENOS and SELENON paralleled with their mRNA expression, indicating that they were regulated at the transcriptional levels. The lack of suitable antibodies prevented us from conducting functional assessment for other selenoproteins in the protein level. Studies suggested that SELENOS, SELENOM, and SELENON play an essential function in lipogenic metabolism and inside the pathogenesis and improvement of obesity [246]. Therefore, we investigated the transcriptionally regulatory mechanisms of SELENOS, SELENOM, and SELENON by dietary Se. We discovered 3 SREBP1c binding web-sites that have been -435 bp/-426 bp region of selenos promoter, -175/-166 bp area of selenom promoter, and -1330/-1321 bp area of selenos promoter, respectively, and that the Se-induced selenos, selenom, and selenon expression was involved in regulating the binding activity of SREBP1c to the area of selenos, selenom, and selenon promoters. To our ideal understanding, at present, only 3 papers decipher the structure and functions of promoter regions of two selenoproteins’ genes, such as selenop and selenof [20,61,62]. For the first time, our study elucidated the transcriptional regulation of selenos, selenom, and selenon genes and indicated that SREBP1cAntioxidants 2021, 10,18 ofdirectly bound to the selenos, selenom, and selenon promoters and mediated Se-induced transcription of selenos, selenom, and selenon. five. Conclusions In summary, our study indicated that dietary marginal and excess Se enhanced lipid deposition of yellow catfish, which was attributable for the up-regulation of lipogenesis, down-regulation of lipolysis, and activation of ER anxiety. Dietary Se addition differentially influenced the expression with the selenogenome. SREBP1c mediated the transcriptional response of selenos, selenom, and selenon by Se.Supplementary Components: The following are available online at https://www.mdpi.com/article/10 .3390/antiox10040535/s1, Figure S1: The relative mRNA levels of 22 selenoproteins (excluding six ER-resident selenoproteins) in the AI of yellow catfish fed diets varying in Se level for 12 wk (Expt. 1), Figure S2: The relative mRNA levels of 22 selenoproteins (excluding six ER-re.