作者: Y. M. Patel , M. D. Lane
关键词: Adipocyte 、 Leupeptin 、 Calpain 、 Cellular differentiation 、 Promoter 、 Ccaat-enhancer-binding proteins 、 Molecular biology 、 Reporter gene 、 Calpastatin 、 Biology
摘要: Evidence is presented that the calcium-activated protease, calpain, required for differentiation of 3T3-L1 preadipocytes into adipocytes induced by methylisobutylxanthine (a cAMP phosphodiesterase inhibitor), dexamethasone, and insulin. Calpain expressed its level falls during differentiation. Exposure to calpain inhibitor N-acetyl-Leu-Leu-norleucinal or overexpression calpastatin, a specific endogenous blocks expression adipocyte-specific genes, notably CCAAT/enhancer-binding protein (C/EBP)α gene, acquisition adipocyte phenotype. The disrupts differentiation-inducing effect (by means cAMP-signaling pathway), but without on dexamethasone N-acetyl-Leu-Leu-norleucinal, inhibits reporter gene mediated C/EBPα promoter preventing C/EBPβ, transcriptional activator from binding promoter. These findings implicate in activation process terminal