共查询到20条相似文献,搜索用时 11 毫秒
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We analyse the role of the empty spiracles (ems) gene in embryonic brain and ventral nerve cord development. ems is differentially expressed in the neurectoderm of the anterior head versus the trunk region of early embryos. A distal enhancer region drives expression in the deutocerebral brain anlage and a proximal enhancer region drives expression in the VNC and tritocerebral brain anlage. Mutant analysis indicates that in the anterior brain ems is necessary for regionalized neurogenesis in the deutocerebral and tritocerebral anlagen. In the posterior brain and VNC ems is necessary for correct axonal pathfinding of specific interneurons. Rescue experiments indicate that the murine Emx2 gene can partially replace the fly ems gene in CNS development. 相似文献
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Storekeeper defines a new class of plant-specific DNA-binding proteins and is a putative regulator of patatin expression 总被引:5,自引:0,他引:5
Zourelidou M de Torres-Zabala M Smith C Bevan MW 《The Plant journal : for cell and molecular biology》2002,30(4):489-497
The expression of class I patatin genes is restricted to potato tubers but can be induced in other tissues by exogenous sucrose. Here we show that tuber-specific and sucrose-inducible gene expression is reduced in transgenic potato plants by mutations in a conserved 10 base pair motif within the B-box of the patatin promoter. In a southwestern screen, we have isolated a novel DNA-binding protein designated Storekeeper (STK) that specifically recognises the B-box motif in vitro. Gel shift experiments with an STK-specific antibody suggest that STK is the B-box binding protein found in tuber nuclei. We propose that STK, the defining member of a new class of DNA binding proteins, regulates patatin expression in potato tubers via the B-box motif. 相似文献
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Mutation of GT-1 binding sites in the Pr-1A promoter influences the level of inducible gene expression in vivo 总被引:10,自引:0,他引:10
Buchel Annemarie S. Brederode Frans Th. Bol John F. Linthorst Huub J.M. 《Plant molecular biology》1999,40(3):387-396
Infection of Nicotiana tabacum Samsun NN with tobacco mosaic virus (TMV) results in a hypersensitive plant response and leads to systemic acquired resistance (SAR). The induction of SAR is mediated by the plant hormone salicylic acid (SA) and is accompanied by the induced expression of a number of genes including the pathogenesis-related (PR) gene 1a. Previously, it has been found that TMV infection and SA treatment resulted in a reduction of binding of nuclear protein GT-1 to far-upstream regions (–902 to –656) of the PR-1a gene. To test if GT-1 is a negative regulator of PR-1a gene expression, the effects of mutations in the seven putative GT-1 binding sites in this region were studied in vitro using dimethyl sulfate interference footprinting and band shift assays. This showed that at least one of the seven sites is indeed a GT-1 binding site. However, when tested in transgenic plants, the mutations did not result in constitutive expression of the chimeric PR-1a/GUS transgene, while inducible expression after SA treatment was decreased. The results suggest that binding of GT-1-like proteins to far-upstream PR-1a promoter regions indeed influences gene expression. A possible model for GT-1's mode of action in PR-1a gene expression is discussed. 相似文献
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Characterization of a novel class of plant homeodomain proteins that bind to the C4 phosphoenolpyruvate carboxylase gene of Flaveria trinervia 总被引:1,自引:0,他引:1
We are interested in the regulatory mechanisms responsible for the mesophyll-specific expression of C4 phosphoenolpyruvate carboxylase (PEPCase). A one-hybrid screen resulted in the cloning of four different members of a novel class of plant homeodomain proteins, which are most likely involved in the mesophyll-specific expression of the C4 PEPCase gene in C4 species of the genus Flaveria. Inspection of the homeodomains of the four proteins reveals that they share many common features with homeodomains described so far, but there are also significant differences. Interestingly, this class of homeodomain proteins occurs also in Arabidopsis thaliana and other C3 plants. One-hybrid experiments as well as in vitro DNA binding studies confirmed that these novel homeodomain proteins specifically interact with the proximal region of the C4 PEPCase gene. The N-terminal domains of the homeodomain proteins contain highly conserved sequence motifs. Two-hybrid experiments show that these motifs are sufficient to confer homo- or heterodimer formation between the proteins. Mutagenesis of conserved cysteine residues within the dimerization domain indicates that these residues are essential for dimer formation. Therefore, we designate this novel class of homeobox proteins ZF-HD, for zinc finger homeodomain protein. Our data suggest that the ZF-HD class of homeodomain proteins may be involved in the establishment of the characteristic expression pattern of the C4 PEPCase gene. 相似文献
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Mark J. Guiltinan John C. Thomas Craig L. Nessler Terry L. Thomas 《Plant molecular biology》1989,13(5):605-610
Nuclear proteins from bean (Phaseolus vulgarus) embryos bind specifically to a 55 bp DNA sequence located upstream of the seed storage protein gene phaseolin. This sequence is capable of elevating gene expression in transgenic tobacco plants by as much as 150-fold when fused to a chimeric -glucuronidase reporter gene. Results presented in this paper demonstrate that nuclear extracts from carrot embryos bind to a phaseolin DNA sequence that includes a phaseolin activator sequence. This specific DNA binding activity is modulated during somatic embryogenesis. Two separable protein species react specifically with the labeled phaseolin DNA fragment (58.0 and 51.7 dDa). These results suggest that the cis- and trans-acting elements controlling gene expression have been highly conserved during evolution.Abbreviations bp
base pairs
- CAMV
cauliflower mosaic virus
- GUS
-glucuronidase
- kDa
kilodalton
- SDS-PAGE
sodium dodecyl sulfate-polyacrylamide gel electrophoresis 相似文献