RT Journal Article SR Electronic T1 The basic domain of plant B-ZIP proteins facilitates import of a reporter protein into plant nuclei. JF The Plant Cell JO Plant Cell FD American Society of Plant Biologists SP 667 OP 675 DO 10.1105/tpc.3.7.667 VO 3 IS 7 A1 van der Krol, A R A1 Chua, N H YR 1991 UL http://www.plantcell.org/content/3/7/667.abstract AB The import of large molecules into the nucleus is an active process that requires the presence in cis of a nuclear localization signal (NLS). Although these signals have been well characterized in mammalian, yeast, and amphibian nuclear proteins, no plant NLS has yet been described. The NLSs identified so far generally contain clusters of basic amino acids. This characteristic feature prompted us to test several basic domains from the plant DNA-binding proteins TGA-1A and TGA-1B and the TATA box-binding protein TFIID for nuclear targeting function. When tested as N-terminal fusions to the beta-glucuronidase protein, only those constructs containing the DNA binding (basic) domain of the basic-zipper (B-ZIP) region of TGA-1A or TGA-1B conferred nuclear import. These results suggest a close association or overlap of the DNA binding and nuclear targeting domains of B-ZIP proteins. We also demonstrated that a wild-type but not a mutant simian virus 40 large T-antigen NLS facilitates import into plant nuclei, indicating a strong conservation between nuclear import mechanisms in animals and plants.