DISTINCT SEQUENCE ELEMENTS IN A NAPIN PROMOTER INTERACT INVITRO WITH DNA-BINDING PROTEINS FROM BRASSICA-NAPUS

Nuclear extracts obtained from developing seeds of oilseed rape, Brassica napus cv. Svalov Karat K20516, were shown to contain several distinct DNA-binding proteins as evidenced by gel retardation experiments. Four of the proteins were capable of interacting in vitro with oligonucleotide probes containing sequences related to motives in a napin gene promoter and its upstream region. Another protein interacted with an A/T-rich repeated sequence present at the 3' end of the gene. The proteins appear to be present also in leaf nuclei and do not show any detectable variations that correlate with napin expression during seed development. Thus, analogous with many transcription factors, the DNA-binding proteins that we have identified are present in both expressing and non-expressing cells.