We have isolated a Xenopus cDNA encoding the YB3 protein which binds specifically to the B box promoter element of class III genes. Northern analysis shows YB3 is expressed in a variety of adult tissues. Fractionation of oocyte S150 extracts demonstrates YB3 is present in phosphocellulose fraction IIIC, as well as in the fraction isolated by B box DNA affinity chromatography. Silver staining in...

Bistability is reported in sensitized Er3+ luminescence driven by an Yb3+ transition that previously revealed an Yb3+ luminescent instability. To our knowledge this is the first report of bistable energy transfer between different rare-earth ions.