Analysis of ANGPTL8 promoter activity and screening of related transcription factors in bovine

Analysing the molecular regulation mechanism of fat deposition in yellow cattle can provide a theoretical basis for the breeding of excellent beef cattle. ANGPTL8 (angiopoietin-like protein 8) promotes the formation of lipid droplets during adipocyte differentiation. To explore the promoter active region of ANGPTL8 and predict potential transcription factors, we further provide a theoretical basis for the functional analysis and regulatory mechanism of ANGPTL8 in adipogenesis. The promoter region of bovine ANGPTL8 was cloned by overlap extension PCR. Online software was used to predict potential transcription factor binding sites, and it identified PPARγ, SREBP1, C/EBPα, and Znf423 transcription factor binding sites in ANGPTL8 promoter region. A luciferase reporter gene vector which contained different deletion fragments of the ANGPTL8 promoter was constructed. Then, the vectors were cotransfected into 293 T cells with the internal control plasmid pRL-TK by cationic liposomes, and the relative fluorescence intensity was detected by a microplate reader. The results of the luciferase activity analysis showed that the core promoter area of ANGPTL8 was in the −885/-227 bp region of the 5′ flanking sequence, while just two SREBP1 binding sites occurred in this area. When SREBP1 was knocked down by siRNA, the expression level of ANGPTL8 was reduced, and we speculated that SREBP1 may be an important transcription factor regulating ANGPTL8 transcription.