Expression of C/EBP delta in rat liver during development and the acute-phase response.

Using Western analysis, C/EBP delta was established in the nuclear extract and nuclear matrix throughout rat liver development and in the adult. During the acute-phase response (APR), C/EBP delta increased in the nuclear extract but remained unchanged in the nuclear matrix of fetal and postnatal rats, whereas it increased in both the nuclear extract and nuclear matrix of the adult. The solubility partitioning of gene regulatory proteins in the nucleus is important for their functioning (Uskoković et al. 2002). The obtained different solubility partitioning profiles of C/EBP delta suggest that its activity is regulated by different mechanisms during development and in the adult.