CLONING OF A NOVEL Y-BOX HOMOLOGY PROTEIN (CHKYB-1HP) CDNA LACKING THE COLD-SHOCK DOMAIN

We have isolated the complete cDNA clone of a novel 262 amino acid Chi cken YB-1 Homology Protein (chkYB-1HP) by screening a chicken embryo c DNA expression library. While the chkYB-1HP is identical over its carb oxyl-terminal 78 amino acids with the Y-box protein YB-1, it differs s trikingly from all other Y-box transcription factors by lacking the co ld-shock domain (CSD). We propose that proteins like chkYB-1HP that la ck the CSD, but retain the hydrophilic carboxyl domain could regulate Y-box proteins through the formation of heterodimeric complexes. (C) 1 998 Elsevier Science B.V.