C/EBPα promotes transcription of the porcine perilipin5 gene

PERILIPIN5 (PLIN5) is a newly discovered member of the PAT family that regulates cellular neutral lipid stores and use. It is expressed in highly oxidative tissues and is induced during fasting. Like other members of the PAT family, PERILIPIN5 expression is also regulated by PPAR alpha. However, its induction by fasting is PPAR alpha-independent. So far, the transcriptional regulation of perilipin5, apart from PPAR alpha, remains unclear. In the present study, we investigated the transcriptional regulation of pig perilipin5 and revealed that its promoter activity was up-regulated by C/EBP alpha. By constructing various progressive deletions and mutants, the binding region of C/EBP alpha was discovered. Furthermore, the binding site was identified by chromatin immunoprecipitation and luciferase reporter assays. Moreover, over-expression of C/EBP alpha induced endogenous perilipin5 expression in the pig kidney cell line IBRS2. Data from arrays showed that C/EBP alpha expression was induced during fasting. Taken together, our results indicate that C/EBP alpha is an essential regulatory factor for perilipin5 transcription and suggest that fasting stimulates perilipin5 transcription through influencing C/EBP alpha expression. (C) 2012 Elsevier Ireland Ltd. All rights reserved.