Isolation and characterization of cDNAs encoding the sea urchin(Strongylocentrotus purpuratus)homologue of the CCAAT binding protein NF-Y A subunit

We have isolated the sea urchin homologue of the mammalian transcription factor NF-Y A subunit (CP-1, CBP) (1, 2). The cloned murine NF-Y A cDNA (3) was used as a template for PCR reactions to amplify the region between amino acids 237-275. This region of the protein is highly conserved in species ranging from yeast to humans (4) and the subunits are functionally interchangeable (5). Low stringency hybridization conditions were used to screen a sea urchin Strongylocentrotus purpuratus cDNA library prepared from 4 cell embryos (4 hr post-fertilization). The nucleotide sequence of the cDNA contains an open reading frame of 400 amino acids. The sea urchin protein is larger than the yeast Hap2 protein, 265 amino acids (6), or the murine, 317 and 346 amino acids (3) and human 347 (3) or 257 (7) amino acids, NF-Y A subunits.