| 152 matches found in 109 documents. Search time: 0.934 seconds. |
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Score: 6.00 |
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| Title: Cloning and characterization of rice ( Oryza sativa L ) telomerase reverse transcriptase , which reveals complex splicing patterns .
| | Author: Heller-Uszynska K Schnippenkoetter W Kilian A | | Journal: Plant J Citation: V : 31 ( 1 ) P : 75-86 Year: 2002 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub12100484 Accession (PMID): 12100484 | | Abstract: Plant chromosomes terminate in telomeres as in other eukaryotes .
Telomeres are vital to genome stability and their malfunctioning is lethal One of the core components of the telomere complex is telomerase .
The enzyme activity depends on RNA ( TER ) and reverse transcriptase ( TERT ) subunits .
We describe here the isolation , sequencing and characterization of the telomerase reverse transcriptase catalytic subunit from the monocot plant Oryza sativa L ( OsTERT ) .
A single copy of this gene is present in the rice genome .
The protein predicted from the OsTERT sequence has all the signature motifs of the TERT family members .
Our data indicate that rice telomerase activity is developmentally regulated and is high in in vitro it issue and cell culture .
However , steady-state transcript levels of the TERT gene do not seem to correlate with enzyme activity .
Northern and RT-PCR analyses of the OsTERT gene transcript profile show multiple differentially spliced transcripts in both telomerase-positive and telomerase-negative it issues .
Based on quantitative analysis of these transcripts , we speculate that the overall balance between the quantities of particular alternatively spliced transcripts may determine whether the TERT protein ( s ) is active or not .
The diversity of splicing variants detected suggests that , as recently discovered for mammalian TERT proteins , rice TERT protein variants may perform functions other than telomere maintenance . | Matching Sentences:
[ Sen. 11, subscore: 2.00 ]: The diversity of splicing variants detected suggests that , as recently discovered for mammalian TERT proteins , rice TERT protein variants may perform functions other than telomere maintenance .
[ Sen. 3, subscore: 1.00 ]: The enzyme activity depends on RNA ( TER ) and reverse transcriptase ( TERT ) subunits .
[ Sen. 6, subscore: 1.00 ]: The protein predicted from the OsTERT sequence has all the signature motifs of the TERT family members .
[ Sen. 8, subscore: 1.00 ]: However , steady-state transcript levels of the TERT gene do not seem to correlate with enzyme activity .
[ Sen. 10, subscore: 1.00 ]: Based on quantitative analysis of these transcripts , we speculate that the overall balance between the quantities of particular alternatively spliced transcripts may determine whether the TERT protein ( s ) is active or not .
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Score: 6.00 |
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| Title: Modeling the tertiary structure of a maize ( Zea mays ssp . mays ) non-symbiotic hemoglobin .
| | Author: Senz-Rivera J Sarath G Arredondo-Peter R | | Journal: Plant Physiol . Biochem . Citation: V : 42 ( 11 ) P : 891-7 Year: 2004 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub15694283 Accession (PMID): 15694283 | | Abstract: The tertiary structure of a maize ( Zea mays ssp . mays ) non-symbiotic hemoglobin ( Hbm ) was modeled using computer tools and the known tertiary structure of rice Hb1 as a template .
This method was tested by predicting the tertiary structure of soybean leghemoglobin a ( Lba ) using rice Hb1 as a template .
The tertiary structures of the predicted and native Lba were similar , indicating that our computer methods could reliably predict the tertiary structures of plant Hbs .
We next predicted the tertiary structure of Hbm .
Hbm appears to have a long pre-helix A and a large CD-loop .
The positions of the distal and proximal His are identical in Hbm and rice Hb1 , which suggests that heme-Fe is hexacoordinate in Hbm and that the kinetic properties of Hbm and rice Hb1 are expected to be very similar , ie that Hbm has a high O2-affinity .
Thermostability analysis showed that Hbm CD-loop is unstable and may provide mobility to amino acids located at the heme pocket for both ligand binding and stabilization and heme-Fe coordination .
Analysis of the C-terminal half of Hbm showed the existence of a pocket-like region ( the N/C cavity ) where interactions with organic molecules or proteins could be possible .
Lys K94 protrudes into the N/C cavity , suggesting that K94 may sense the binding of molecules to the N/C cavity .
Thus , it is likely that the instability of the CD-loop and the possibility of binding molecules to the N/C cavity are essential for positioning amino acids in the heme pocket and in regulating Hbm activity and function . | Matching Sentences:
[ Sen. 1, subscore: 2.00 ]: The tertiary structure of a maize ( Zea mays ssp . mays ) non-symbiotic hemoglobin ( Hbm ) was modeled using computer tools and the known tertiary structure of rice Hb1 as a template .
[ Sen. 3, subscore: 2.00 ]: The tertiary structures of the predicted and native Lba were similar , indicating that our computer methods could reliably predict the tertiary structures of plant Hbs .
[ Sen. 2, subscore: 1.00 ]: This method was tested by predicting the tertiary structure of soybean leghemoglobin a ( Lba ) using rice Hb1 as a template .
[ Sen. 4, subscore: 1.00 ]: We next predicted the tertiary structure of Hbm .
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Score: 5.00 |
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| Title: Characterization of Oryza sativa telomerase reverse transcriptase and possible role of its phosphorylation in the control of telomerase activity .
| | Author: Oguchi K Tamura K Takahashi H | | Journal: Gene Citation: V : 342 ( 1 ) P : 57-66 Year: 2004 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub15527966 Accession (PMID): 15527966 | | Abstract: Telomerase reverse transcriptase ( TERT ) has been characterized in the dicotyledon Arabidopsis thaliana .
A TERT homolog has now been identified in the monocotyledon rice ( Oryza sativa L ) on the basis of its predicted homology to the A thaliana enzyme ( AtTERT ) .
At least five alternatively spliced transcripts of the rice TERT ( OsTERT ) gene were detected .
The full-length OsTERT protein shares structural features with TERTs of other species , including a calculated molecular size of 144 kDa , an isoelectric point of 9 . 6 , and conserved sequence motifs .
Phylogenetic analysis showed that OsTERT clusters with AtTERT and is more related to the human and mouse enzymes than to those of yeast and ciliated protozoa , consistent with the evolutionary relations among these eukaryotes .
Telomerase activity was abundant in shoot apices and cultured cells but was low or absent in leaves or roots of rice plants , whereas similarly spliced OsTERT transcripts were detected in all it issues examined and cultured cells .
Similar to mouse and human TERT proteins , OsTERT contains two putative phosphorylation sites for Akt kinase .
Incubation of a rice cell extract with Akt or with protein phosphatase 2A potentiated or inhibited telomerase activity , respectively , whereas Akt did not affect the activity in Arabidopsis cell extract .
In addition , the kinase activated the telomerase in a leaf extract .
The mechanism of telomerase regulation in rice thus appears to differ from that in Arabidopsis ( which is mediated predominantly at the level of AtTERT transcription ) , possibly reflecting the taxonomic distance between monocotyledons and dicotyledons . | Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: Telomerase reverse transcriptase ( TERT ) has been characterized in the dicotyledon Arabidopsis thaliana .
[ Sen. 2, subscore: 1.00 ]: A TERT homolog has now been identified in the monocotyledon rice ( Oryza sativa L ) on the basis of its predicted homology to the A thaliana enzyme ( AtTERT ) .
[ Sen. 3, subscore: 1.00 ]: At least five alternatively spliced transcripts of the rice TERT ( OsTERT ) gene were detected .
[ Sen. 4, subscore: 1.00 ]: The full-length OsTERT protein shares structural features with TERTs of other species , including a calculated molecular size of 144 kDa , an isoelectric point of 9 . 6 , and conserved sequence motifs .
[ Sen. 7, subscore: 1.00 ]: Similar to mouse and human TERT proteins , OsTERT contains two putative phosphorylation sites for Akt kinase .
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Score: 5.00 |
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| Title: Fingerprinting Noncanonical and Tertiary RNA Structures by Differential SHAPE Reactivity .
| | Author: Steen KA Rice GM Weeks KM | | Journal: J Am Chem Soc Citation: V : 134 P : 13160-3 Year: 2012 Type: In-Data-Review | | Literature: oryza Field: abstract Doc ID: pub22852530 Accession (PMID): 22852530 | | Abstract: Many RNA structures are composed of simple secondary structure elements linked by a few critical tertiary interactions .
SHAPE chemistry has made interrogation of RNA dynamics at single-nucleotide resolution straightforward .
However , de novo identification of nucleotides involved in tertiary interactions remains a challenge .
Here we show that nucleotides that form noncanonical or tertiary contacts can be detected by comparing information obtained using two SHAPE reagents , N-methylisatoic anhydride ( NMIA ) and 1-methyl-6-nitroisatoic anhydride ( 1M6 ) .
Nucleotides that react preferentially with NMIA exhibit slow local nucleotide dynamics and usually adopt the less common C2-endo ribose conformation .
Experiments and first-principles calculations show that 1M6 reacts preferentially with nucleotides in which one face of the nucleobase allows an unhindered stacking interaction with the reagent .
Differential SHAPE reactivities were used to detect noncanonical and tertiary interactions in four RNAs with diverse structures and to identify preformed noncanonical interactions in partially folded RNAs .
Differential SHAPE reactivity analysis will enable experimentally concise , large-scale identification of tertiary structure elements and ligand binding sites in complex RNAs and in diverse biological environments .
| Matching Sentences:
[ Sen. 1, subscore: 1.00 ]: Many RNA structures are composed of simple secondary structure elements linked by a few critical tertiary interactions .
[ Sen. 3, subscore: 1.00 ]: However , de novo identification of nucleotides involved in tertiary interactions remains a challenge .
[ Sen. 4, subscore: 1.00 ]: Here we show that nucleotides that form noncanonical or tertiary contacts can be detected by comparing information obtained using two SHAPE reagents , N-methylisatoic anhydride ( NMIA ) and 1-methyl-6-nitroisatoic anhydride ( 1M6 ) .
[ Sen. 7, subscore: 1.00 ]: Differential SHAPE reactivities were used to detect noncanonical and tertiary interactions in four RNAs with diverse structures and to identify preformed noncanonical interactions in partially folded RNAs .
[ Sen. 8, subscore: 1.00 ]: Differential SHAPE reactivity analysis will enable experimentally concise , large-scale identification of tertiary structure elements and ligand binding sites in complex RNAs and in diverse biological environments .
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Score: 4.00 |
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| Title: Carbohydrates , dietary glycaemic load and glycaemic index , and risk of acute myocardial infarction .
| | Author: Tavani A Bosetti C Negri E Augustin LS Jenkins DJ La Vecchia C | | Journal: Heart Citation: V : 89 ( 7 ) P : 722-6 Year: 2003 Type: ARTICLE | | Literature: oryza Field: abstract Doc ID: pub12807839 Accession (PMID): 12807839 | | Abstract: OBJECTIVES : To assess the relation between selected carbohydrate foods , dietary glycaemic load and glycaemic index , and the risk of non-fatal acute myocardial infarction in a population with a high intake of refined carbohydrates .
DESIGN AND SETTING : Hospital based case-control study conducted in Milan , Italy , between 1995 and 1999 .
PATIENTS : 433 non-diabetic subjects with a first episode of non-fatal acute myocardial infarction , and 448 controls admitted to hospital for a wide spectrum of acute conditions unrelated to known or potential risk factors for acute myocardial infarction .
METHODS : Information was collected by interviewer administered questionnaires .
Multivariate odds ratios ( OR ) and 95% confidence intervals ( CI ) were obtained by multiple logistic regression models .
RESULTS : Compared with patients in the lowest tertile of intake , the multivariate OR for those in the highest tertile was 1 . 00 for bread , 1 . 27 for pasta and rice , 1 . 38 for soups , 0 . 78 for potatoes , 0 . 97 for desserts , and 1 . 00 for sugar .
The OR for the highest tertile of score was 1 . 08 for glycaemic load and 1 . 38 for glycaemic index None of the estimates was significant .
A significant association with acute myocardial infarction risk was found for glycaemic index in patients aged > or = 60 years ( OR 1 . 81 , 95% CI 1 . 07 to 3 . 07 for the highest tertile of score compared with the lowest ) and in those with a body mass index > or = 25 kg/m2 ( OR 2 . 02 , 95% CI 1 . 21 to 3 . 34 ) .
CONCLUSIONS : In this Italian population high glycaemic load and glycaemic index were not strongly associated with acute myocardial infarction risk , but slightly increased odds ratios were observed for glycaemic index in elderly people and in association with overweight .
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[ Sen. 6, subscore: 2.00 ]: RESULTS : Compared with patients in the lowest tertile of intake , the multivariate OR for those in the highest tertile was 1 . 00 for bread , 1 . 27 for pasta and rice , 1 . 38 for soups , 0 . 78 for potatoes , 0 . 97 for desserts , and 1 . 00 for sugar .
[ Sen. 7, subscore: 1.00 ]: The OR for the highest tertile of score was 1 . 08 for glycaemic load and 1 . 38 for glycaemic index None of the estimates was significant .
[ Sen. 8, subscore: 1.00 ]: A significant association with acute myocardial infarction risk was found for glycaemic index in patients aged > or = 60 years ( OR 1 . 81 , 95% CI 1 . 07 to 3 . 07 for the highest tertile of score compared with the lowest ) and in those with a body mass index > or = 25 kg/m2 ( OR 2 . 02 , 95% CI 1 . 21 to 3 . 34 ) .
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