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Full-Text Articles in Life Sciences

Altered Collective Mitochondrial Dynamics In The Arabidopsis Msh1 Mutant Compromising Organelle Dna Maintenance, Joanna M. Chustecki, Ross D. Etherington, Daniel J. Gibbs, Iain G. Johnston Jun 2022

Altered Collective Mitochondrial Dynamics In The Arabidopsis Msh1 Mutant Compromising Organelle Dna Maintenance, Joanna M. Chustecki, Ross D. Etherington, Daniel J. Gibbs, Iain G. Johnston

Department of Biochemistry: Faculty Publications

Mitochondria form highly dynamic populations in the cells of plants (and almost all eukaryotes). The characteristics and benefits of this collective behaviour, and how it is influenced by nuclear features, remain to be fully elucidated. Here, we use a recently developed quantitative approach to reveal and analyse the physical and collective ‘social’ dynamics of mitochondria in an Arabidopsis msh1 mutant where the organelle DNA maintenance machinery is compromised. We use a newly created line combining the msh1 mutant with mitochondrially targeted green fluorescent protein (GFP), and characterize mitochondrial dynamics with a combination of single-cell time-lapse microscopy, computational tracking, and network …


The Mitochondrial Nad+ Transporter (Ndt1) Plays Important Roles In Cellular Nad+ Homeostasis In Arabidopsis Thaliana, Izabel De Souza Chaves, Elias Feitosa-Araujo, Alexandra Florian, David B. Medeiros, Paula Da Fonseca-Pereira, Lennart Charton, Elmien Heyneke, Jorge A. C. Apfata, Marcel V. Pires, Tabea Mettler-Altmann, Wagner L. Arajuo, H. Ekkehard Neuhaus, Ferdinando Palmieri, Toshihiro Obata, Andreas P. M. Weber, Nicole Linka, Alisdair R. Femie, Adriano Nunes-Nesi Jan 2019

The Mitochondrial Nad+ Transporter (Ndt1) Plays Important Roles In Cellular Nad+ Homeostasis In Arabidopsis Thaliana, Izabel De Souza Chaves, Elias Feitosa-Araujo, Alexandra Florian, David B. Medeiros, Paula Da Fonseca-Pereira, Lennart Charton, Elmien Heyneke, Jorge A. C. Apfata, Marcel V. Pires, Tabea Mettler-Altmann, Wagner L. Arajuo, H. Ekkehard Neuhaus, Ferdinando Palmieri, Toshihiro Obata, Andreas P. M. Weber, Nicole Linka, Alisdair R. Femie, Adriano Nunes-Nesi

Department of Biochemistry: Faculty Publications

Nicotinamide adenine dinucleotide (NAD+) is an essential coenzyme required for all living organisms. In eukaryotic cells, the final step of NAD+ biosynthesis is exclusively cytosolic. Hence, NAD+ must be imported into organelles to support their metabolic functions. Three NAD+ transporters belonging to the mitochondrial carrier family (MCF) have been biochemically characterized in plants. AtNDT1 (At2g47490), focus of the current study, AtNDT2 (At1g25380), targeted to the inner mitochondrial membrane, and AtPXN (At2g39970), located in the peroxisomal membrane. Although AtNDT1 was presumed to reside in the chloroplast …


Overexpression Of Patatin-Related Phospholipase Aiiiβ Altered The Content And Composition Of Sphingolipids In Arabidopsis, Maoyin Li, Jennifer E. Markham, Xuemin Wang Oct 2014

Overexpression Of Patatin-Related Phospholipase Aiiiβ Altered The Content And Composition Of Sphingolipids In Arabidopsis, Maoyin Li, Jennifer E. Markham, Xuemin Wang

Department of Biochemistry: Faculty Publications

In plants, fatty acids are primarily synthesized in plastids and then transported to the endoplasmic reticulum (ER) for synthesis of most of the complex membrane lipids, including glycerolipids and sphingolipids. The first step of sphingolipid synthesis, which uses a fatty acid and a serine as substrates, is critical for sphingolipid homeostasis; its disruption leads to an altered plant growth. Phospholipase As have been implicated in the trafficking of fatty acids from plastids to the ER. Previously, we found that overexpression of a patatin-related phospholipase, pPLAIIIβ, resulted in a smaller plant size and altered anisotropic cell expansion. Here, we determined the …


Characterization Of Udp-Arabinopyranose Mutase Genes In The Arabidopsis Cell Wall Mutant Mur5, Christopher A. Hart May 2014

Characterization Of Udp-Arabinopyranose Mutase Genes In The Arabidopsis Cell Wall Mutant Mur5, Christopher A. Hart

Honors Scholar Theses

The genome of Arabidopsis thaliana contains several coding regions for UDP-arabinopyranose mutases (UAMs) that are also known as reversibly glycosylated polypeptides (RGPs). The mur5 cell wall mutant of Arabidopsis shows a 30% decrease in cell wall arabinose content, and a missense mutation in the Reversibly Glycosylated Polypeptide 2 gene was recently proposed to cause this mutant phenotype. Through a traditional complementation analysis, mur5 and a T-DNA insertion mutant in the RGP2 gene were shown not to complement each other, indicating that the two genes are mutant alleles of the same locus. The mur5 SNP located in RGP2 caused a more …


Comparative Metabolic Profiling Of Haberlea Rhodopensis, Thellungiella Halophyla, And Arabidopsis Thaliana Exposed To Low Temperature, Maria Benina, Toshihiro Obata, Nikolay Mehterov, Ivan Ivanov, Veselin Petrov, Valentina Toneva, Alisdair R. Fernie, Tsanko S. Gechev Jan 2013

Comparative Metabolic Profiling Of Haberlea Rhodopensis, Thellungiella Halophyla, And Arabidopsis Thaliana Exposed To Low Temperature, Maria Benina, Toshihiro Obata, Nikolay Mehterov, Ivan Ivanov, Veselin Petrov, Valentina Toneva, Alisdair R. Fernie, Tsanko S. Gechev

Department of Biochemistry: Faculty Publications

Haberlea rhodopensis is a resurrection species with extreme resistance to drought stress and desiccation but also with ability to withstand low temperatures and freezing stress. In order to identify biochemical strategies which contribute to Haberlea's remarkable stress tolerance, the metabolic reconfiguration of H. rhodopensis during low temperature (4C) and subsequent return to optimal temperatures (21C) was investigated and compared with that of the stress tolerant Thellungiella halophyla and the stress sensitive Arabidopsis thaliana. Metabolic analysis by GC-MS revealed intrinsic differences in the metabolite levels of the three species even at 21C. H. rhodopensis …


Host Pathogen Interactions: Is Arabidopsis Thaliana Remembered By Its Nemesis Pseudomonas Syringae?, Daniel Z. Kreiser May 2012

Host Pathogen Interactions: Is Arabidopsis Thaliana Remembered By Its Nemesis Pseudomonas Syringae?, Daniel Z. Kreiser

Lawrence University Honors Projects

Plants contain innate immune systems that deter pathogen infection. Pattern recognition receptors bind microbe-associated molecular patterns (MAMPs), triggering immunity. MAMPs are proteins exclusive to pathogens that are typically indispensable for their survival. For this reason, MAMPs cannot be mutated or removed without causing pathogen death. However, this does not necessitate constitutive expression of MAMPs. In this study, the MAMP response of Arabidopsis thaliana was utilized to determine differential detection of MAMPs expressed by Pseudomonas syringe pv. tomato DC3000 when pretreated with A. thaliana. Results demonstrated that more MAMPs are detected when P. syringae had previously encountered A. thaliana, …


The Pyruvate, Orthophosphate Dikinase Regulatory Proteins Of Arabidopsis Possess A Novel, Unprecedented Ser/Thr Protein Kinase Primary Structure, Chris J. Chastain, Wenxin Xu, Kate Parsley, Gautam Sarath, Jullian Hebberd, Raymond Chollet Feb 2008

The Pyruvate, Orthophosphate Dikinase Regulatory Proteins Of Arabidopsis Possess A Novel, Unprecedented Ser/Thr Protein Kinase Primary Structure, Chris J. Chastain, Wenxin Xu, Kate Parsley, Gautam Sarath, Jullian Hebberd, Raymond Chollet

Department of Biochemistry: Faculty Publications

Pyruvate, orthophosphate dikinase (PPDK) is a ubiquitous, low-abundance metabolic enzyme of undetermined function in C3 plants. Its activity in C3 chloroplasts is light-regulated via reversible phosphorylation of an active-site Thr residue by the PPDK regulatory protein (RP), a most unusual bifunctional protein kinase (PK)/ protein phosphatase (PP). In this paper we document the molecular cloning and functional analysis of the two unique C3 RPs in Arabidopsis thaliana. The first of these, AtRP1, encodes a typical chloroplast-targeted, bifunctional C4-like RP. The second RP gene, AtRP2, encodes a monofunctional polypeptide that possesses in vitro RP-like PK activity but lacks PP activity, …


Arabidopsis Atspl14, A Plant-Specific Sbp-Domain Transcription Factor, Participates In Plant Development And Sensitivity To Fumonisin B1, Julie M. Stone, Xinwen Liang, Emily R. Nekl, Justin J. Stiers Mar 2005

Arabidopsis Atspl14, A Plant-Specific Sbp-Domain Transcription Factor, Participates In Plant Development And Sensitivity To Fumonisin B1, Julie M. Stone, Xinwen Liang, Emily R. Nekl, Justin J. Stiers

Department of Biochemistry: Faculty Publications

The recessive Arabidopsis thaliana fumonisin B1-resistant (fbr6) mutant was identified by its ability to survive in the presence of a programmed cell death (PCD)-inducing fungal toxin FB1. The fbr6 mutant also displays altered plant architecture in the absence of FB1, most notably elongated petioles and enhanced leaf margin serration. These phenotypes are a result of a T-DNA insertion in the SQUAMOSA promoter binding protein (SBP) domain gene, AtSPL14. AtSPL14 encodes a plant-specific protein with features characteristic of a transcriptional regulator, including a nuclear localization signal sequence, a plant-specific DNA binding domain (the SBP box), and a protein …


Evidence For An Epigenetic Mechanism By Which Hsp90 Acts As A Capacitor For Morphological Evolution, Vincent E. Sollars, Xiangyi Lu, Li Xiao, Xiaoyan Wang, Mark D. Garfinkel, Douglas M. Ruden Dec 2002

Evidence For An Epigenetic Mechanism By Which Hsp90 Acts As A Capacitor For Morphological Evolution, Vincent E. Sollars, Xiangyi Lu, Li Xiao, Xiaoyan Wang, Mark D. Garfinkel, Douglas M. Ruden

Biochemistry and Microbiology

Morphological alterations have been shown to occur in Drosophila melanogaster when function of Hsp90 (heat shock 0-kDa protein 1α, encoded by Hsp83) is compromised during development1. Genetic selection maintains the altered phenotypes in subsequent generations1. Recent experiments have shown, however, that phenotypic variation still occurs in nearly isogenic recombinant inbred strains of Arabidopsis thaliana2. Using a sensitized isogenic D. melanogaster strain, iso-KrIf-1, we confirm this finding and present evidence supporting an epigenetic mechanism for Hsp90’s capacitor function, whereby reduced activity of Hsp90 induces a heritably altered chromatin state. The altered chromatin state is evidenced by ectopic expression …