The 5‘—flanking cis—acting elements of the human ε—globin gene associates with the nuclear matrix and binds to the nuclear matrix proteins

The nuclear matrix attachment regions(MARs) and the binding nuclear matrix proteins in the 5'-flanking cisacting elements of the human e-globin gene have been examined.Using in vitro DNA-matrix binding assay,it has been shown that the positive stage-specific regulatory element (e-PREII,-446bp- -419bp) upstream of this gene could specifically associate with the nuclear matrix from K562 cells,indicating that e-PREII may be an erythroidspecific facultative MAR.In gel mobility shift assay and Southwestern blotting assay,an erythroid-specific nuclear matrix protein (e-NMPk) in K562 cells has been revealed to bind to this positive regulatory element (e-PREII).Furthermore,we demonstrated that the silencer (-392bp- -177bp) upstream of the human e-globin gene could associate with the nuclear matrices from K562,HEL and Raji cells.In addition,the nuclear matrix proteins prepared from these three cell lines could also bind to this silencer,suggesting that this silencer element might be a constitutive nuclear matrix attachment region(constitutive MAR).Our results demonstrated that the nuclear matrix and nuclear matrix proteins might play an important role in the regulation of the human e-globin gene expression.