Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.31 (beta-glucuronidase)
 7,680 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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PMID:The basic domain of plant B-ZIP proteins facilitates import of a reporter protein into plant nuclei. 184 23

TGA factors play a key role in plant defense by binding to the promoter region of defense genes, inducing expression. Salicylic acid (SA) induces the expression of the gene encoding NIMIN-1, which interacts with NPR1/NIM1, a key regulator of systemic acquired resistance. We investigated whether the TGA2-binding motif TGACG located upstream of the NIMIN-1 gene is necessary for SA induction of NIMIN-1 expression. A mutated version of the NIMIN-1 promoter was created by site-directed mutagenesis. We generated T-DNA constructs in which native NIMIN-1 and mutated promoters were fused to green fluorescent protein and beta-glucuronidase reporters. We produced transgenic Arabidopsis plants and observed NIMIN-1 promoter-driven green fluorescent protein expression in the roots, petiole and leaves. Constructs were agroinfiltrated into the leaves for transient quantitative assays of gene expression. Using quantitative real-time RT-PCR, we characterized the normal gene response to SA and compared it to the response of the mutant version of the NIMIN-1 promoter. Both the native NIMIN-1 construct and an endogenous copy of NIMIN-1 were induced by SA. However, the mutated promoter construct was much less sensitive to SA than the native NIMIN-1 promoter, indicating that this TGA2-binding motif is directly involved in the modulation of SA-induced NIMIN-1 expression in Arabidopsis.
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PMID:Functional analysis of a TGA factor-binding site located in the promoter region controlling salicylic acid-induced NIMIN-1 expression in Arabidopsis. 2019 73