| 92 matches found in 46 documents. Search time: 0.27 seconds. |
|---|
|
Score: 6.00 |
|---|
| Title: Expression of a 434 : VP16 chimeric activator leads to high-level activation of gene expression in stable transformants of Arabidopsis .
| | Author: Storgaard M Didion T Okkels F Nielse KK .
| | Journal: Transgenic Res .
Citation: V : 11 ( 2 ) P : 151-9 Year: 2002 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub12054349 Accession (PMID): 12054349 | | Abstract: The performance of an expression system based on a fusion of the bacteriophage 434-repressor to the VP16 activation domain of Herpes simplex virus type 1 ( 434 : VP16 ) was tested after stable integration into Arabidopsis .
A special feature of this system was the use of the monocot maize ubiquitin1 and rice actin1 promoters to drive the expression of the 434 : VP16 activator and 434-repressor , respectively .
Our results demonstrate that the maize ubiquitin1 and the rice actin1 promoters , each of which contain introns , are active in Arabidopsis and can be used to express genes in this dicot species .
Activation of gene expression after co-integration of the activator and reporter cassettes into the same genomic locus resulted in a higher activation level ( 84-fold activation ) compared to crossing individual lines expressing only the activator or the operator reporter cassette alone ( 9-fold activation ) .
Increasing the number of operator elements in the reporter cassette from 1 to 4 increased the activation level in cross-activated lines to an average of 281-fold with one combination of parental lines giving a 900-fold activation .
Simultaneous expression of the 434-repressor protein driven by the rice actin promoter resulted in a significant decrease in the 434 : VP16 mediated reporter gene expression .
Nevertheless , an overall induction via 434 : VP16 was possible even in the presence of the 434-repressor protein .
This feature is important for genes which need to be absolutely repressed except under activating conditions .
To our knowledge this investigation is the first report on the use of the 434 : VP16 chimeric activator in an expression system in stably transformed plant lines .
| Matching Sentences:
[ Sen. 1, subscore: 2.00 ]: The performance of an expression system based on a fusion of the bacteriophage 434-repressor to the VP16 activation domain of Herpes simplex virus type 1 ( 434 : VP16 ) was tested after stable integration into Arabidopsis .
[ Sen. 2, subscore: 1.00 ]: A special feature of this system was the use of the monocot maize ubiquitin1 and rice actin1 promoters to drive the expression of the 434 : VP16 activator and 434-repressor , respectively .
[ Sen. 6, subscore: 1.00 ]: Simultaneous expression of the 434-repressor protein driven by the rice actin promoter resulted in a significant decrease in the 434 : VP16 mediated reporter gene expression .
[ Sen. 7, subscore: 1.00 ]: Nevertheless , an overall induction via 434 : VP16 was possible even in the presence of the 434-repressor protein .
[ Sen. 9, subscore: 1.00 ]: To our knowledge this investigation is the first report on the use of the 434 : VP16 chimeric activator in an expression system in stably transformed plant lines .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 5.00 |
|---|
| Title: A molecular genetic analysis of Eragrostis tef ( Zucc . ) Trotter : non-coding regions of chloroplast DNA , 18S rDNA and the transcription factor VP1 .
| | Author: Espelund M Bekele E Holst-Jensen A Jakobsen KS Nordal I | | Journal: Hereditas Citation: V : 132 ( 3 ) P : 193-202 Year: Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub11075514 Accession (PMID): 11075514 | | Abstract: The non-coding chloroplast DNA sequences of the trnL ( UAA ) intron and the trnL-trnF ( GAA ) intergeneric spacer ( IGS ) , the coding sequences of nuclear 18S rDNA , and the transcription factor Vp1 of the cereal tef ( Eragrostis tef ( Zucc . ) Trotter ) were studied .
No intraspecific variation was found among the 6 studied tef varieties .
However , the study displayed that Eragrostis tef has a number of unique traits compared to other grasses .
Phylogenetic analysis of the chloroplast DNA gave three grass clades , joining Eragrostis with sorghum and maize in one .
In the analysis of the 18S rDNA sequences , the three grass species were joined in a monophyletic trichotomy in the cladogram , in which maize is the most divergent , rice the least and tef intermediate .
The Vp1 is highly conserved .
The Vp1 phylogeny showed that the tef Vp1-sequence is the hitherto most divergent Vp1-sequence reported from a grass .
| Matching Sentences:
[ Sen. 7, subscore: 3.00 ]: The Vp1 phylogeny showed that the tef Vp1-sequence is the hitherto most divergent Vp1-sequence reported from a grass .
[ Sen. 1, subscore: 1.00 ]: The non-coding chloroplast DNA sequences of the trnL ( UAA ) intron and the trnL-trnF ( GAA ) intergeneric spacer ( IGS ) , the coding sequences of nuclear 18S rDNA , and the transcription factor Vp1 of the cereal tef ( Eragrostis tef ( Zucc . ) Trotter ) were studied .
[ Sen. 6, subscore: 1.00 ]: The Vp1 is highly conserved .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 5.00 |
|---|
| Title: Functional interactions of lanthanum and phospholipase D with the abscisic acid signaling effectors VP1 and ABI1-1 in rice protoplasts .
| | Author: Gampala SS Hagenbeek D Rock CD .
| | Journal: J Biol . Chem . Citation: V : 276 ( 13 ) P : 9855-60 Year: 2001 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub11139577 Accession (PMID): 11139577 | | Abstract: cis , trans-Abscisic acid ( ABA ) plays an important role in plant growth and development , regulation of seed maturation , germination , and adaptation to environmental stresses .
Knowledge of ABA mechanisms of action and the interactions of components required for ABA signal transduction is far from complete .
Using transient gene expression in rice protoplasts , we observed additive and inhibitory effects between maize VP1 ( Viviparous-1 , a transcriptional activator ) and a dominant-negative mutant protein phosphatase , ABI1-1 ( ABA-insensitive-1-1 ) , from Arabidopsis .
Lanthanide ions were shown to be specific agonists of ABA-inducible gene expression and to interact synergistically with ABA and overexpressed VP1 .
Both VP1 and lanthanum activities could be antagonized by coexpression of ABI1-1 , which demonstrates the specific ABA dependence of these effectors on ABA-regulated gene expression .
We obtained pharmacological evidence that phospholipase D ( PLD ) functions in ABA-inducible gene expression in rice .
Antagonism of ABA , VP1 , and lanthanum synergy by 1-butanol , a specific inhibitor of PLD , was similar to the inhibition by coexpression of ABI1-1 .
These results demonstrate that ABA , VP1 , lanthanum , PLD , and ABI1 are all involved in ABA-regulated gene expression and are consistent with an integrated model whereby La ( 3+ ) acts upstream of PLD . | Matching Sentences:
[ Sen. 3, subscore: 1.00 ]: Using transient gene expression in rice protoplasts , we observed additive and inhibitory effects between maize VP1 ( Viviparous-1 , a transcriptional activator ) and a dominant-negative mutant protein phosphatase , ABI1-1 ( ABA-insensitive-1-1 ) , from Arabidopsis .
[ Sen. 4, subscore: 1.00 ]: Lanthanide ions were shown to be specific agonists of ABA-inducible gene expression and to interact synergistically with ABA and overexpressed VP1 .
[ Sen. 5, subscore: 1.00 ]: Both VP1 and lanthanum activities could be antagonized by coexpression of ABI1-1 , which demonstrates the specific ABA dependence of these effectors on ABA-regulated gene expression .
[ Sen. 7, subscore: 1.00 ]: Antagonism of ABA , VP1 , and lanthanum synergy by 1-butanol , a specific inhibitor of PLD , was similar to the inhibition by coexpression of ABI1-1 .
[ Sen. 8, subscore: 1.00 ]: These results demonstrate that ABA , VP1 , lanthanum , PLD , and ABI1 are all involved in ABA-regulated gene expression and are consistent with an integrated model whereby La ( 3+ ) acts upstream of PLD .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 5.00 |
|---|
| Title: Cloning and expression of a sorghum gene with homology to maize vp1 .
Its potential involvement in pre-harvest sprouting resistance .
| | Author: Carrari F Perez-Flore L Lijavetzky D Enciso S Sanchez R Benech-Arnold R Iusem N | | Journal: Plant Mol . Biol . Citation: V : 45 ( 6 ) P : 631-40 Year: 2001 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub11430426 Accession (PMID): 11430426 | | Abstract: Pre-harvest sprouting ( PHS ) in sorghum is related to the lack of a normal dormancy level during seed development and maturation .
Based on previous evidence that seed dormancy in maize is controlled by the vp1 gene , we used a PCR-based approach to isolate two Sorghum bicolor genomic and cDNA clones from two genotypes exhibiting different PHS behaviour and sensitivity to abscisic acid ( ABA ) .
The two 699 amino acid predicted protein sequences differ in two residues at positions 341 ( Gly or Cys within the repression domain ) and 448 ( Pro or Ser ) and show over 80 , 70 and 60% homology to maize , rice and oat VP1 proteins respectively .
Expression analysis of the sorghum vp1 gene in the two lines shows a slightly higher level of vp1 mRNA in the embryos susceptible to PHS than in those resistant to PHS during embryogenesis .
However , timing of expression was different between these genotypes during this developmental process .
Whereas for the former the main peak of expression was observed at 20 days after pollination ( DAP ) , the peak in the latter was found at later developmental stages when seed maturation was almost complete .
Under favourable germination conditions and in the presence of fluridone ( an inhibitor of ABA biosynthesis ) , sorghum vp1 mRNA showed to be consistently correlated with sensitivity to ABA but not with ABA content and dormancy .
| Matching Sentences:
[ Sen. 4, subscore: 2.00 ]: Expression analysis of the sorghum vp1 gene in the two lines shows a slightly higher level of vp1 mRNA in the embryos susceptible to PHS than in those resistant to PHS during embryogenesis .
[ Sen. 2, subscore: 1.00 ]: Based on previous evidence that seed dormancy in maize is controlled by the vp1 gene , we used a PCR-based approach to isolate two Sorghum bicolor genomic and cDNA clones from two genotypes exhibiting different PHS behaviour and sensitivity to abscisic acid ( ABA ) .
[ Sen. 3, subscore: 1.00 ]: The two 699 amino acid predicted protein sequences differ in two residues at positions 341 ( Gly or Cys within the repression domain ) and 448 ( Pro or Ser ) and show over 80 , 70 and 60% homology to maize , rice and oat VP1 proteins respectively .
[ Sen. 7, subscore: 1.00 ]: Under favourable germination conditions and in the presence of fluridone ( an inhibitor of ABA biosynthesis ) , sorghum vp1 mRNA showed to be consistently correlated with sensitivity to ABA but not with ABA content and dormancy .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 5.00 |
|---|
| Title: Self-guanylylation of birnavirus VP1 does not require an intact polymerase activity site .
| | Author: Pan J Lin L Tao YJ | | Journal: Virology Citation: V : 395 P : 87-96 Year: 2009 Type: MEDLINE | | Literature: oryza Field: abstract Doc ID: pub19801157 Accession (PMID): 19801157 | | Abstract: Protein priming is an important mechanism that many viruses use to initiate genomic DNA or RNA synthesis .
Birnaviruses are the only double-stranded ( ds ) RNA viruses that use protein priming .
The viral-encoded VP1 of birnavirus functions as both a polymerase and a protein primer and is able to undergo self-guanylylation to acquire a covalently linked rGMP .
By employing biochemical assays using recombinant proteins , we have shown that VP1 self-guanylylation does not require an RNA template but is dependent on divalent metal ions .
VP1 reacts with all four types of rNTPs but strongly prefers rGTP .
Unexpectedly , two fatal polymerase mutants D402A and E421Y , each having an essential catalytic residue mutated and unable to catalyze RNA synthesis , remain active in self-guanylylation .
The guanylylation site was further mapped to the VP1 N-terminal domain .
Our results support a mechanism in which VP1 self-guanylylation is catalyzed by a novel active site different from the polymerase active site .
| Matching Sentences:
[ Sen. 3, subscore: 1.00 ]: The viral-encoded VP1 of birnavirus functions as both a polymerase and a protein primer and is able to undergo self-guanylylation to acquire a covalently linked rGMP .
[ Sen. 4, subscore: 1.00 ]: By employing biochemical assays using recombinant proteins , we have shown that VP1 self-guanylylation does not require an RNA template but is dependent on divalent metal ions .
[ Sen. 5, subscore: 1.00 ]: VP1 reacts with all four types of rNTPs but strongly prefers rGTP .
[ Sen. 7, subscore: 1.00 ]: The guanylylation site was further mapped to the VP1 N-terminal domain .
[ Sen. 8, subscore: 1.00 ]: Our results support a mechanism in which VP1 self-guanylylation is catalyzed by a novel active site different from the polymerase active site .
| | Supplemental links/files: reference in endnote online text related articles pubmed citation | |
