Molecular cloning and characterization of the sheep α-TTP gene and its expression in response to different vitamin E status.
The α-tocopherol transfer protein (α-TTP) is a ~32 kDa protein that exhibits a marked ligand specificity and selectively recognizes of α-tocopherol, which is the most active form of vitamin E. The α-TTP gene has been cloned and its physiological functions have been studied in numbers of species, however, the understanding of sheep α-TTP is still in his infancy. In this study, the full-length cDNA of sheep α-TTP gene was cloned from sheep liver by using of rapid amplification of complementary DNA ends (RACE). As a result, the sheep α-TTP gene was 1098 bp in nucleotide which contained 23 bp 5'-untranslated region (UTR), 226 bp 3'-UTR and 849 bp open reading frame (ORF) that encoded a basic protein of 282 amino acids. Further bioinformatic analysis indicated that the sheep α-TTP gene had a high homologous of both nucleotide and amino acid sequences compared with that of other species and had a Sec14p-like lipid-binding domain which called the CRAL-TRIO domain. Moreover, the expression of sheep α-TTP mRNA and protein in response to different vitamin E supplemented levels were observed according to quantitative real-time PCR (qRT-PCR) and Western blotting analysis. The results showed that dietary vitamin E levels did not affect α-TTP mRNA expression significantly while the low vitamin E supplemented level groups of sheep had significantly higher α-TTP protein compared to high-vitamin E groups.
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, 2 Yuan Mingyuan Xilu, Haidian District, Beijing 100193, PR China.
Kun
K
Liu
Hai-Ling
HL
Luo
Du-Bing
DB
Yue
Su-Yun
SY
Ge
Fei
F
Yuan
Le-Yan
LY
Yan
Hui-Na
HN
Jia
D000818:Animals; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D015870:Gene Expression; D012756:Sheep / Q000235:genetics*; D014810:Vitamin E / Q000378:metabolism*
D002352:Carrier Proteins; C017763:alpha-tocopherol transfer protein; D014810:Vitamin E