Interactions between the nuclear matrix proteins and the 5′-flankingcis-acting elements of the human ε-globin gene

An erythroid-specific nuclear matrix protein (termed ε-NMPk) in K562 cells, which can specifically bind to the positive stage-specific regulatory element (ε-PRE II, - 446 - 419 bp) upstream of the human ε-globin gene, has been identified by using gel mobility shift assay. Meanwhile, Southwestern blotting assay showed that the nuclear matrix protein ε-NMPk in K562, cells may be composed of two polypeptides (～ 40 ku). In addition, it is observed in the gel mobility shift assay that the nuclear matrix proteins from K562, HEL and Raji cells can bind to the silencer DNA (- 392 - 177 bp) in the 5′-flanking sequence of human ε-globin gene respectively. However, the shift band K detected in K562 cells is different from shift band H/R in HEL and Raji cells, suggesting that a common nuclear matrix protein may exist in HEL and Raji cells. Results show that the nuclear matrix protein may play an important role in the regulation of the human ε-globin gene expression.