Characterization of the human myeloid cell nuclear differentiation antigen: relationship to interferon-inducible proteins.

The human myeloid cell nuclear differentiation antigen (MNDA) is expressed specifically in cells of the granulocyte/monocyte lineage. The MNDA has been isolated by using a monoclonal antibody affinity matrix and reversed-phase high performance liquid chromatography. Its NH2-terminal sequence has been obtained, as well as additional sequence information derived from peptides produced by cyanogen bromide and SV8 protease cleavages. Meaningful similarities were observed in extended regions between the MNDA and the reported beta interferon-inducible proteins, 202 and 204, from Ehrlich ascites mouse tumor cells. An amphipathic, basic alpha-helical region, showing no similarity to the 202 and 204 proteins, exhibited close similarity to a region in the interferon response factor-2, a protein which binds the interferon stimulated response element. The relatively high number of S(T)PXX motifs present in the partial amino acid sequence of the MNDA, described herein, suggests that the MNDA binds DNA and is a transcription factor.