Binding of the TATA-binding protein (TBP) to the promoter is the first and rate 
limiting step in the formation of transcriptional complexes. We show here that 
nuclear import of TBP is mediated by a new karyopherin (Kap) (importin) family 
member, Kap114p. Kap114p is localized to the cytoplasm and nucleus. A complex of 
Kap114p and TBP was detected in the cytosol and could be reconstituted using 
recombinant proteins, suggesting that the interaction was direct. Deletion of 
the KAP114 gene led to specific mislocalization of TBP to the cytoplasm. We also 
describe two other potential minor import pathways for TBP. Consistent with 
other Kaps, the dissociation of TBP from Kap114p is dependent on RanGTP. 
However, we could show that double stranded, TATA-containing DNA stimulates this 
RanGTP-mediated dissociation of TBP, and is necessary at lower RanGTP 
concentrations. This suggests a mechanism where, once in the nucleus, TBP is 
preferentially released from Kap114p at the promoter of genes to be transcribed. 
In this fashion Kap114p may play a role in the intranuclear targeting of TBP.