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Full-Text Articles in Molecular Biology
The Role Of Gtp Binding And Hydrolysis At The Attoc159 Preprotein Receptor During Protein Import Into Chloroplasts, Danny Schnell, F. Wang, B. Agne, F. Kessler
The Role Of Gtp Binding And Hydrolysis At The Attoc159 Preprotein Receptor During Protein Import Into Chloroplasts, Danny Schnell, F. Wang, B. Agne, F. Kessler
Danny Schnell
The majority of nucleus-encoded chloroplast proteins are targeted to the organelle by direct binding to two membrane-bound GTPase receptors, Toc34 and Toc159. The GTPase activities of the receptors are implicated in two key import activities, preprotein binding and driving membrane translocation, but their precise functions have not been defined. We use a combination of in vivo and in vitro approaches to study the role of the Toc159 receptor in the import reaction. We show that atToc159-A864R, a receptor with reduced GTPase activity, can fully complement a lethal insertion mutation in the ATTOC159 gene. Surprisingly, the atToc159-A864R receptor increases the rate …
Heat Shock Protein 101 Effects In A. Thaliana: Genetic Variation, Fitness And Pleiotropy In Controlled Temperature Conditions., S. J. Tonsor, C. Scott, I. Boumaza, Elizabeth Vierling
Heat Shock Protein 101 Effects In A. Thaliana: Genetic Variation, Fitness And Pleiotropy In Controlled Temperature Conditions., S. J. Tonsor, C. Scott, I. Boumaza, Elizabeth Vierling
Elizabeth Vierling
The Hsp100/ClpB heat shock protein family is ancient and required for high temperature survival, but natural variation in expression and its phenotypic effects is unexplored in plants. In controlled environment experiments, we examined the effects of variation in the Arabidopsis cytosolic AtHsp101 (hereafter Hsp101). Ten wild-collected ecotypes differed in Hsp101 expression responses across a 22 to 40 degrees C gradient. Genotypes from low latitudes expressed the least Hsp101. We tested fitness and pleiotropic consequences of varying Hsp101 expression in 'control' vs. mild thermal stress treatments (15/25 degrees C D/N vs. 15/25 degrees D/N plus 3 h at 35 degrees C …
Modulation Of Nitrosative Stress By S-Nitrosoglutathione Reductase Is Critical For Thermotolerance And Plant Growth In Arabidopsis, Ung Lee, Chris Wie, Bernadette O. Fernandez, Martin Feelisch, Elizabeth Vierling
Modulation Of Nitrosative Stress By S-Nitrosoglutathione Reductase Is Critical For Thermotolerance And Plant Growth In Arabidopsis, Ung Lee, Chris Wie, Bernadette O. Fernandez, Martin Feelisch, Elizabeth Vierling
Elizabeth Vierling
Nitric oxide (NO) is a key signaling molecule in plants. This analysis of Arabidopsis thaliana HOT5 (sensitive to hot temperatures), which is required for thermotolerance, uncovers a role of NO in thermotolerance and plant development. HOT5 encodes S-nitrosoglutathione reductase (GSNOR), which metabolizes the NO adduct S-nitrosoglutathione. Two hot5 missense alleles and two T-DNA insertion, protein null alleles were characterized. The missense alleles cannot acclimate to heat as dark-grown seedlings but grow normally and can heat-acclimate in the light. The null alleles cannot heat-acclimate as light-grown plants and have other phenotypes, including failure to grow on nutrient plates, increased reproductive shoots, …
Core Genome Responses Involved In Acclimation To High Temperature, Jane Larkindale, Elizabeth Vierling
Core Genome Responses Involved In Acclimation To High Temperature, Jane Larkindale, Elizabeth Vierling
Elizabeth Vierling
Plants can acclimate rapidly to environmental conditions, including high temperatures. To identify molecular events important for acquired thermotolerance, we compared viability and transcript profiles of Arabidopsis thaliana treated to severe heat stress (45°C) without acclimation or following two different acclimation treatments. Notably, a gradual increase to 45°C (22°C to 45°C over 6 h) led to higher survival and to more and higher-fold transcript changes than a step-wise acclimation (90 min at 38°C plus 120 min at 22°C before 45°C). There were significant differences in the total spectrum of transcript changes in the two treatments, but core components of heat acclimation …
Arabidopsis Tic40 Expression In Tobacco Chloroplasts Results In Massive Proliferation Of The Inner Envelope Membrane And Upregulation Of Associated Proteins, Danny Schnell, N. D. Singh, M. Li, S. B. Lee, H Daniell
Arabidopsis Tic40 Expression In Tobacco Chloroplasts Results In Massive Proliferation Of The Inner Envelope Membrane And Upregulation Of Associated Proteins, Danny Schnell, N. D. Singh, M. Li, S. B. Lee, H Daniell
Danny Schnell
The chloroplast inner envelope membrane (IM) plays essential roles in lipid synthesis, metabolite transport, and cellular signaling in plants. We have targeted a model nucleus-encoded IM protein from Arabidopsis thaliana, pre-Tic40-His, by relocating its expression from the nucleus to the chloroplast genome. Pre-Tic40-His was properly targeted, processed, and inserted. It attained correct topology and was folded and assembled into a TIC complex, where it accounted for up to 15% of the total chloroplast protein. These results confirm the existence of a novel pathway for protein targeting to the IM. Tic40-His overexpression resulted in a massive proliferation of the IM (up …
Auto-Hydroxylation Of Fih-1: An Fe(Ii), Α-Ketoglutarate-Dependent Human Hypoxia Sensor, Yuan-Han Chen, Lindsay M. Comeaux, Stephen J. Eyles, Michael J. Knapp
Auto-Hydroxylation Of Fih-1: An Fe(Ii), Α-Ketoglutarate-Dependent Human Hypoxia Sensor, Yuan-Han Chen, Lindsay M. Comeaux, Stephen J. Eyles, Michael J. Knapp
Stephen J. Eyles
HIF-asparaginyl hydroxylase (FIH-1) normally couples O(2)-activation to hydroxylation of Asn(803) on the alpha-subunit of the hypoxia-inducible factor (HIFalpha), a key step in pO(2) sensing; in the absence of HIFalpha, O(2)-activation becomes uncoupled, leading to self-hydroxylation at Trp(296) and a purple Fe(iii)-O-Trp chromophore-this alternative reactivity may affect human hypoxia sensing.