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 PPARα. However, its induction by fasting is PPARα-independent. So far, the transcriptional regulation of perilipin5, apart from PPARα, 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/EBPα. By constructing various progressive deletions and mutants, the binding region of C/EBPα was discovered. Furthermore, the binding site was identified by chromatin immunoprecipitation and luciferase reporter assays. Moreover, over-expression of C/EBPα induced endogenous perilipin5 expression in the pig kidney cell line IBRS2. Data from arrays showed that C/EBPα expression was induced during fasting. Taken together, our results indicate that C/EBPα is an essential regulatory factor for perilipin5 transcription and suggest that fasting stimulates perilipin5 transcription through influencing C/EBPα expression.