CLONING, STRUCTURE, CELLULAR-LOCALIZATION, AND POSSIBLE FUNCTION OF THE TUMOR-SUPPRESSOR GENE LETHAL(3)MALIGNANT BLOOD NEOPLASM-1 OF DROSOPHILA-MELANOGASTER

The tumor suppressor gene, lethal (3) malignant blood neoplasm-1(+), o f Drosophila melanogaster is required for the differentiation of the p hagocytic blood-cell type, the plasmatocyte. In the homozygously mutat ed state it causes the malignant transformation of these blood cells. We present here the cloning, sequencing, structure, and expression of the l(3)mbn-1(+) gene during development. The cloned gene was identifi ed by germ-line transformation, generation of revertants, and the dete ction of the corresponding mRNA in blood cells and other tissues. Homo logies of the G-S-rich C-terminus of the putative MBN(83) protein to h uman cytokeratins K1, K10, and mouse loricrin were found. The structur e and possible function of the wild-type l(3)mbn-1(+) gene are discuss ed. (C) 1994 Academic Press, Inc.