Human translocation liposarcoma-CCAAT/enhancer binding protein (C/EBP) homologous protein (TLS-CHOP) oncoprotein prevents adipocyte differentiation by directly interfering with C/EBPbeta function..     ///    "Being that CHOP is a member of the C/EBP transcription factor family, proteins that comprise part of the adipocyte differentiation machinery, we examined whether TLS-CHOP blocked adipocyte differentiation by directly interfering with C/EBP function. "    ///    "In contrast, the TLS-CHOP basic region was dispensable, making it unlikely that the inhibitory effect of TLS-CHOP is attributable to unscheduled gene expression resulting from TLS-CHOP's putative transactivation activity. "    ///    This effect of TLS-CHOP required a functional leucine zipper domain and correlated with its ability to heterodimerize with C/EBPbeta and inhibit C/EBPbeta DNA binding and transactivation activity in situ.     ///    "Together, the results demonstrate that TLS-CHOP blocks adipocyte differentiation by directly preventing C/EBPbeta from binding to and transactivating its target genes. "    ///    TLS-CHOP was extremely effective at blocking adipocyte differentiation when expressed at a level comparable to that observed in human myxoid liposarcoma.     ///    "Using a single-step retroviral infection protocol, either wild-type or mutant TLS-CHOP were co-expressed along with C/EBPbeta in na?ve NIH3T3 cells, and their ability to inhibit C/EBPbeta-driven adipogenesis was determined. "