IDENTIFICATION AND DEVELOPMENTAL CHARACTERIZATION OF A NOVEL Y-BOX PROTEIN FROM DROSOPHILA-MELANOGASTER

The Y-box proteins are a family of highly conserved nucleic acid bindi ng proteins which are conserved from bacteria to human. In this report we have identified a new member of this family from Drosophila melano gaster. Degenerate-PCR was used to identify a conserved region within the highly conserved cold-shock domain (CSD) of Y-box proteins. Subseq uently, the cDNA for this gene was sequenced, and the identified open reading frame was named ypsilon schachtel (yps). The expression patter n of yps indicates that this gene is expressed throughout development with the highest level of expression found in adult flies, In situ hyb ridization shows that the yps mRNA is maternally loaded into the egg c ytoplasm. In addition, there appears to be expression of yps mRNA in m esodermal tissue during embryogenesis. YPS, while containing a conserv ed CSD, is novel in that it completely lacks the alternating acidic an d basic regions found in the C-terminus of the other vertebrate eukary otic Y-box proteins. The CSD of yps was purified and gel-shift analysi s showed that this domain can interact with RNA, We predict that YPS w ould be an RNA-binding protein due to these results and the motifs whi ch have been identified within the amino acid sequence.