CLONING OF THE MURINE HOMOLOG OF THE LEUKEMIA-ASSOCIATED PML GENE

PML, a Ring-finger protein, participates in the disruption of normal m yeloid differentiation when fused to the retinoic acid receptor alpha (RAR alpha) by the translocation between Chromosomes (Chrs) 15 and 17 in acute promyelocytic leukemia (APL). As an initial step in the chara cterization of PML in species other than human, a murine cDNA clone of the PML gene was isolated and sequenced, and the intron/exon organiza tion of the murine locus determined. The predicted amino acid sequence of the mouse PML protein shows 80% similarity to that of its human ho molog. However, the mouse and human proteins show greater than 90% sim ilarity in the proposed functional domains of the proteins. Despite it s role in the etiology of APL, PML expression is not detectably altere d during granulocytic differentiation in a murine in vitro system. Chr omosomal localization of the Pml locus by somatic cell hybrids and by linkage analysis indicates that the gene maps to a region of mouse Chr 9 with known linkage homology to the region on human Chr 15q to which PML has been localized.