State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, Qinghai Province 810016, People's Republic of China; College of Agriculture and Animal Husbandry, Qinghai University, Xining, Qinghai Province 810016, People's Republic of China.
College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, 712100, PR China.
Res Vet Sci. 2021 Dec;141:174-179. doi: 10.1016/j.rvsc.2021.10.018. Epub 2021 Oct 30.
Fatty acid binding protein 4 (FABP4) was crucial to fatty acid uptake and intracellular transport. However, the mechanisms regulating yak (Bos grunniens) FABP4 transcription were not determined. In the current study, predominant expression levels of yak FABP4 were identified in subcutaneous fat and longissimus dorsi muscles by quantitative real-time polymerase chain reactions (qPCR). The CCAAT/enhancer binding protein alpha (CEBPα) and myocyte enhancer factor 2A (MEF2A), as transcriptional activator or repressor in the promoter region of FABP4, were confirmed by both site-directed mutagenesis experiment and chromatin immunoprecipitation assay. Additionally, molecular mechanisms of CEBPɑ regulation were analyzed to explore the transcriptional regulatory property of FABP4, which indicated that transcriptional activity of CEBPɑ depended on CCAAT/ enhancer binding protein beta (CEBPβ) transcription factor. Our results demonstrated that CEBPβ binding directly to the promoter region drove CEBPɑ transcription, improving yak FABP4 transcriptional activity in adipocytes. This mechanism expanded the information on the transcriptional regulatory network of adipogenesis.
脂肪酸结合蛋白 4（FABP4）对于脂肪酸的摄取和细胞内运输至关重要。然而，调控牦牛（Bos grunniens）FABP4 转录的机制尚不清楚。在本研究中，通过定量实时聚合酶链反应（qPCR）确定了牦牛 FABP4 在皮下脂肪和背最长肌中的主要表达水平。CCAAT/增强子结合蛋白α（CEBPα）和肌细胞增强因子 2A（MEF2A）作为 FABP4 启动子区域的转录激活或抑制因子，通过定点诱变实验和染色质免疫沉淀实验得到了证实。此外，还分析了 CEBPɑ 的调控分子机制，以探讨 FABP4 的转录调控特性，结果表明 CEBPɑ 的转录活性依赖于 CCAAT/增强子结合蛋白β（CEBPβ）转录因子。我们的研究结果表明，CEBPβ 直接结合启动子区域驱动 CEBPɑ 转录，从而提高了脂肪细胞中牦牛 FABP4 的转录活性。该机制扩展了关于脂肪生成转录调控网络的信息。
