3 matches found in 3 documents. Search time: 0.269 seconds. |
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Score: 1.00 | Title: Regulation of rice NADPH oxidase by binding of Rac GTPase to its N-terminal extension .
| Author: Wong HL Pinontoan R Hayashi K Tabata R Yaeno T Hasegawa K Kojima C Yoshioka H Iba K Kawasaki T Shimamoto K | Journal: Plant Cell Citation: V : 19 P : 4022-34 Year: 2007 Type: In-Process | Literature: oryza Field: abstract Doc ID: pub18156215 Accession (PMID): 18156215 | Abstract: Reactive oxygen species ( ROS ) produced by NADPH oxidase play critical roles in various cellular activities , including plant innate immunity response .
In contrast with the large multiprotein NADPH oxidase complex of phagocytes , in plants , only the homologs of the catalytic subunit gp91phox and the cytosolic regulator small GTPase Rac are found .
Plant homologs of the gp91phox subunit are known as Rboh ( for respiratory burst oxidase homolog ) .
Although numerous Rboh have been isolated in plants , the regulation of enzymatic activity remains unknown .
All rboh genes identified to date possess a conserved N-terminal extension that contains two Ca2+ binding EF-hand motifs .
Previously , we ascertained that a small GTPase Rac ( Os Rac1 ) enhanced pathogen-associated molecular pattern-induced ROS production and resistance to pathogens in rice ( Oryza sativa ) .
In this study , using yeast two-hybrid assay , we found that interaction between Rac GTPases and the N-terminal extension is ubiquitous and that a substantial part of the N-terminal region of Rboh , including the two EF-hand motifs , is required for the interaction .
The direct Rac-Rboh interaction was supported by further studies using in vitro pull-down assay , a nuclear magnetic resonance titration experiment , and in vivo fluorescence resonance energy transfer ( FRET ) microscopy .
The FRET analysis also suggests that cytosolic Ca2+ concentration may regulate Rac-Rboh interaction in a dynamic manner .
Furthermore , transient coexpression of Os Rac1 and rbohB enhanced ROS production in Nicotiana benthamiana , suggesting that direct Rac-Rboh interaction may activate NADPH oxidase activity in plants .
Taken together , the results suggest that cytosolic Ca2+ concentration may modulate NADPH oxidase activity by regulating the interaction between Rac GTPase and Rboh .
| Matching Sentences: [ Sen. 10, subscore: 1.00 ]: Furthermore , transient coexpression of Os Rac1 and rbohB enhanced ROS production in Nicotiana benthamiana , suggesting that direct Rac-Rboh interaction may activate NADPH oxidase activity in plants .
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Score: 1.00 | Title: Crystallographic characterization of the N-terminal domain of a plant NADPH oxidase .
| Author: Oda T Hashimoto H Kuwabara N Hayashi K Kojima C Kawasaki T Shimamoto K Sato M Shimizu T | Journal: Acta Crystallogr Sect F Struct Biol Cryst Commun Citation: V : 64 P : 867-9 Year: 2008 Type: MEDLINE | Literature: oryza Field: abstract Doc ID: pub18765925 Accession (PMID): 18765925 | Abstract: Respiratory burst oxidase homologue ( Rboh ) , which is found in the plasma membrane , is a generator of reactive oxygen species ( ROS ) in plants .
Many studies have indicated that the ROS produced by Rboh play critical roles in various cellular activities , including plant defence against pathogens .
Crystals of the N-terminal domain of Oryza sativa RbohB ( OsRbohB ) have been obtained .
The crystals belonged to space group P2 ( 1 ) 2 ( 1 ) 2 ( 1 ) , with unit-cell parameters a = 60 . 4 , b = 72 . 2 , c = 118 . 9 A An intensity data set was collected to 2 . 4 A resolution .
| Matching Sentences: [ Sen. 3, subscore: 1.00 ]: Crystals of the N-terminal domain of Oryza sativa RbohB ( OsRbohB ) have been obtained .
| Supplemental links/files: reference in endnote online text related articles pubmed citation | |
Score: 1.00 | Title: Structure of the N-terminal regulatory domain of a plant NADPH oxidase and its functional implications .
| Author: Oda T Hashimoto H Kuwabara N Akashi S Hayashi K Kojima C Wong HL Kawasaki T Shimamoto K Sato M Shimizu T | Journal: J Biol Chem Citation: V : 285 P : 1435-45 Year: 2010 Type: MEDLINE | Literature: oryza Field: abstract Doc ID: pub19864426 Accession (PMID): 19864426 | Abstract: Plant NADPH oxidases ( Rboh , for respiratory burst oxidase homolog ) produce reactive oxygen species that are key regulators of various cellular events including plant innate immunity .
Rbohs possess a highly conserved cytoplasmic N-terminal region containing two EF-hand motifs that regulate Rboh activity .
Rice ( Oryza sativa ) RbohB ( OsRbohB ) is regulated by the direct binding of a small GTPase ( Rac1 ) to this regulatory region as well as by Ca ( 2+ ) binding to the EF-hands .
Here , we present the atomic structure of the N-terminal region of OsRbohB .
The structure reveals that OsRbohB forms a unique dimer stabilized by swapping the EF-hand motifs .
We identified two additional EF-hand-like motifs that were not predicted from sequence data so far .
These EF-hand-like motifs together with the swapped EF-hands form a structure similar to that found in calcineurin B We observed conformational changes mediated by Ca ( 2+ ) binding to only one EF-hand .
Structure-based in vitro pulldown assays and NMR titration experiments defined the OsRac1 binding interface within the coiled-coil region created by swapping the EF-hands .
In addition , we demonstrate a direct intramolecular interaction between the N and C terminus , and that the complete N-terminal cytoplasmic region is required for this interaction .
The structural features and intramolecular interactions characterized here might be common elements shared by Rbohs that contribute to the regulation of reactive oxygen species production .
| Matching Sentences: [ Sen. 3, subscore: 1.00 ]: Rice ( Oryza sativa ) RbohB ( OsRbohB ) is regulated by the direct binding of a small GTPase ( Rac1 ) to this regulatory region as well as by Ca ( 2+ ) binding to the EF-hands .
| Supplemental links/files: reference in endnote online text related articles pubmed citation | |