Expression of the protein tyrosine phosphatase beta 2 gene in mouse erythroleukemia cells induces terminal erythroid differentiation

We have cloned cDNA for protein tyrosine phosphatase beta 2, which had been implicated in erythroid differentiation of mouse erythroleukemia cells. Expression of cDNA constructs, in which beta 2 cDNA is placed under the control of mouse metallothionein-I promoter, by ZnCl2, converted a significant portion (20 to 38%) of the cells to erythroid-like cells, which is 25-50% of the erythroid differentiation efficiency observed by conventional erythroid-inducing agents, Furthermore, introduction and expression of altered protein tyrosine phosphatase beta 2 cDNA constructs designed to produce the enzyme lacking the phosphatase activity inhibited erythroid differentiation by 100-20%, depending upon the concentration of erythroid-inducing agents employed. These results strongly suggest that protein tyrosine phosphatase beta 2 is involved in triggering erythroid differentiation in mouse erythroleukemia cells.