cDNA Cloning, Tissue Distribution, and Chromosomal Localization of Myelodysplasia/Myeloid Leukemia Factor 2 (MLF2)

A fusion gene between nucleophosmin (NPM) and myelodysplasia/myeloid leukemia factor 1 (MLF1) is formed by a recurrent t(3;5)(q25.1;q34) in myelodysplastic syndrome and acute myeloid leukemia. Here we report the identification of a novel gene,MLF2,which contains an open reading frame of 744 bp encoding a 248-amino-acid protein highly related to the previously identified MLF1 protein (63% similarity, 40% identity). In contrast to the tissue-restricted expression pattern ofMLF1,theMLF2messenger RNA is expressed ubiquitously. TheMLF2gene locus was mapped by fluorescencein situhybridization to human chromosome 12p13, a chromosomal region frequently involved in translocations and deletions in acute leukemias of lymphoid or myeloid lineage. In a physical map of chromosome 12,MLF2was found to reside on the yeast artificial chromosome clone 765b9. Southern blotting analysis of malignant cell DNAs prepared from a series of acute lymphoblastic leukemia cases with translocations involving chromosome arm 12p, as well as a group of acute myeloid leukemias with various cytogenetic abnormalities, failed to revealMLF2gene rearrangements.