CLONING AND CHARACTERIZATION OF A HUMAN DEAH-BOX RNA HELICASE, A FUNCTIONAL HOMOLOG OF FISSION YEAST CDC28 PRP8/

During the splicing process, spliceosomal snRNAs undergo numerous conf ormational rearrangements that appear to be catalyzed by proteins belo nging to the DEAD/H-box superfamily of RNA helicases, We have cloned a new RNA helicase gene, designated DBP2 (DEAH-hox protein), homologous to the Schizosaccaromyces pombe cdc28(+)/prp8(+) gene involved in pre -mRNA splicing and cell cycle progression. The full-length DBP2 contai ns 3400 nucleotides and codes for a protein of 1041 amino acids with a calculated mel. wt of 119 037 Da, Transfection experiments demonstrat ed that the GFP-DBP2 gene product, transiently expressed in HeLa cells , was localized in the nucleus, The DBP2 gene was mapped by FISH to th e MHC region on human chromosome 6p21.3, a region where many malignant , genetic and autoimmune disease genes are linked, Because the express ion of DBP2 gene in S.pombe prp8 mutant cells partially rescued the te mperature-sensitive phenotype, we conclude that DBP2 isa functional hu man homolog of the fission yeast Cdc28/Prp8 protein.