title: Characterization and Expression of Chicken Selenoprotein U.
abstract: Selenoprotein U (SelU) may regulate a myriad of biological processes through its redox function. In chicks, neither the nucleotide sequence nor the amino acid sequence is known. The main objectives of this study were to clone and characterize the chicken Selu gene and investigate Selu messenger RNA (mRNA) and protein expression in chicken tissues. The coding sequence (CDS) of Selu contained 387 bases with a typical mammalian selenocysteine insertion sequence (SECIS) located in the 3'-untranslated region. The deduced amino acid sequence of chicken SelU contains 224 amino acids with UAA as the stop codon. Like all SelU genes identified in different species, chicken SelU contains one well-conserved selenocysteine (Sec) at the 85th position encoded by the UGA codon. The SECIS element was with the conserved denosine (--AAA--) rather than the motif cytidine (--CC--) motif. Moreover, the expression pattern of Selu mRNA in muscle, liver, kidney, heart, spleen, lung, testis, and brain was analyzed with real-time quantitative PCR in young male chickens fed a Se-deficient corn-soybean meal basal diet supplemented with 0.0 and 0.3 mg Se/kg in the form of sodium selenite. We found that the abundance of Selu mRNA in muscle, liver, kidney, heart, spleen, and lung was downregulated (P < 0.05) by Se deficiency. However, it was not affected by dietary Se concentrations in testis and brain. Furthermore, protein abundance of SelU in these seven tissues was consistent with the mRNA abundance. Hence, we suggest that Selu might play an important role in the biochemical function of Se in birds.
authors: Beijing Laboratory of Food Quality and Safety, and Key Laboratory of Functional Dairy, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
authors: Yun-Yun
authors: YY
authors: Jiang
authors: Jia-Qiang
authors: JQ
authors: Huang
authors: Gao-Chao
authors: GC
authors: Lin
authors: Hui-Yuan
authors: HY
authors: Guo
authors: Fa-Zheng
authors: FZ
authors: Ren
authors: Hao
authors: H
authors: Zhang
mesh_terms: D000818:Animals; D002645:Chickens; D008297:Male; D016133:Polymerase Chain Reaction; D051140:Selenoproteins / Q000235:genetics / Q000378:metabolism*; D018038:Sodium Selenite
chemical_list: D051140:Selenoproteins; D018038:Sodium Selenite