A5005978885- Plant Molecular Biology Research
- Plant responses to water stress
- Plant Reproductive Biology
- Photosynthetic Processes and Mechanisms
- Ubiquitin and proteasome pathways
- Plant Gene Expression Analysis
- Autophagy in Disease and Therapy
- Mitochondrial Function and Pathology
- Microbial Metabolic Engineering and Bioproduction
- Plant-Microbe Interactions and Immunity
- Metabolomics and Mass Spectrometry Studies
- Coastal wetland ecosystem dynamics
- Mass Spectrometry Techniques and Applications
- Peptidase Inhibition and Analysis
- Lipid metabolism and biosynthesis
- Plant Stress Responses and Tolerance
- Legume Nitrogen Fixing Symbiosis
- Genomics and Phylogenetic Studies
- Plant Parasitism and Resistance
- Rice Cultivation and Yield Improvement
- Plant Virus Research Studies
- Biochemical and Molecular Research
- Plant Surface Properties and Treatments
- Signaling Pathways in Disease
- Molecular Biology Techniques and Applications
National University of Ireland, Maynooth
2015-2024
Kildare Education Centre
2019
University of Edinburgh
2018
Centre National de la Recherche Scientifique
2000-2017
Sorbonne Université
2002-2017
Institut Jacques Monod
2002-2017
Trinity College Dublin
2009-2015
California Institute of Technology
2004-2009
Institut de Chimie des Substances Naturelles
2005
Université Paris Cité
2005
How different organs are formed from small sets of undifferentiated precursor cells is a key question in developmental biology. To understand the molecular mechanisms underlying organ specification plants, we studied function homeotic selector genes APETALA3 (AP3) and PISTILLATA (PI), which control formation petals stamens during Arabidopsis flower development. this end, characterized activities transcription factors that AP3 PI encode throughout development by using perturbation assays as...
The floral organ identity factor AGAMOUS (AG) is a key regulator of Arabidopsis thaliana flower development, where it involved in the formation reproductive organs as well control meristem determinacy. To obtain insights into how AG specifies fate, we determined genes and processes acting downstream this C function during early development distinguished between direct indirect effects. end, combined genome-wide localization studies, gene perturbation experiments, computational analyses. Our...
The transcription factors LEAFY (LFY) and APETALA1 (AP1), together with the AP1 paralog CAULIFLOWER (CAL), control onset of flower development in a partially redundant manner. This redundancy is thought to be mediated, at least part, through regulation shared set target genes. However, whether these genes are independently or cooperatively regulated by LFY AP1/CAL currently unknown. To better understand regulatory relationship between obtain deeper insights into floral initiation, we...
The ubiquitin-dependent N-end rule pathway relates the in vivo half-life of a protein to identity its N-terminal residue. This proteolytic system is present all organisms examined and has been shown have multitude functions animals fungi. In plants, however, functional understanding only beginning. hierarchic structure. Destabilizing activity Asp, Glu, (oxidized) Cys requires their conjugation Arg by an arginyl-tRNA-protein transferase (R-transferase). resulting recognized pathway's E3...
A fundamental question in biology is how organisms integrate the plethora of environmental cues that they perceive to trigger a co-ordinated response. The regulation protein stability, which largely mediated by ubiquitin-proteasome system eukaryotes, plays pivotal role these processes. Due their sessile lifestyle and need respond rapidly multitude factors, plants are thought be especially dependent on proteolysis regulate cellular In this review, we present complexity ubiquitin plants,...
Abstract BIG/DARK OVEREXPRESSION OF CAB1/TRANSPORT INHIBITOR RESPONSE3 is a 0.5 MDa protein associated with multiple functions in Arabidopsis (Arabidopsis thaliana) signaling and development. However, the biochemical of BIG are unknown. We investigated role for Arg/N-degron pathways, which substrate fate influenced by N-terminal residue. crossed big loss-of-function allele to 2 N-degron pathway E3 ligase mutants, proteolysis6 (prt6) prt1, examined stability substrates. Stability model...
CP12 is an 8.5-kDa nuclear-encoded chloroplast protein, isolated from higher plants. It forms part of a core complex two dimers phosphoribulokinase (PRK), tetramers glyceraldehyde 3-phosphate dehydrogenase (GAPDH), and CP12. The role in this assembly has not been determined. To address question, we cloned cDNA encoding the mature green alga Chlamydomonas reinhardtii expressed it Escherichia coli. Sequence alignments show that very similar to other CP12s, with four conserved cysteine residues...
The N-end rule relates the in vivo half-life of a protein to identity its N-terminal residue. Primary destabilizing residues (Nd p ) are recognized directly by targeting machinery. recognition secondary s is preceded conjugation an Nd residue polypeptide substrate. In eukaryotes, ATE1 -encoded arginyl-transferases (R D,E,C* -transferases) conjugate Arg (R), residue, Asp (D), Glu (E), or oxidized Cys (C*). Ubiquitin ligases recognize substrate and target (ubiquitylated) proteasome....
The N-end rule relates the in vivo half-life of a protein to identity its N-terminal amino acid residue. While some residues result metabolically stable proteins, other, so-called destabilizing residues, lead rapid turnover. pathway, which mediates recognition and degradation proteins with is present all organisms examined, including prokaryotes. This pathway has hierarchical organization called primary are directly recognized by specific ubiquitin ligases. Other termed secondary tertiary...
The formation of flowers is one the main model systems to elucidate molecular mechanisms that control developmental processes in plants. Although several studies have explored gene expression during flower development plant Arabidopsis thaliana on a genome-wide scale, continuous series data from earliest floral stages until maturation has been lacking. Here, we used induction system close this information gap and generate reference dataset for stage-specific formation. Using system,...
Abstract To efficiently counteract pathogens, plants rely on a complex set of immune responses that are tightly regulated to allow the timely activation, appropriate duration and adequate amplitude defense programs. The coordination plant response is known require activity ubiquitin/proteasome system, which controls stability proteins in eukaryotes. Here, we demonstrate N-end rule pathway, subset regulates against wide range bacterial fungal pathogens model Arabidopsis thaliana . We show...
The gene regulatory network comprised of LEAFY (LFY), APETALA1 (AP1), the AP1 paralog CAULIFLOWER (CAL), and TERMINAL FLOWER1 (TFL1) is a major determinant flowering process in Arabidopsis thaliana. TFL1 activity shoot apical meristem provides inflorescence identity while transcription factors LFY AP1/CAL confer floral to emerging primordia. It has been thought that control onset part by repressing expression flowers. However, June issue Plant Physiology, we reported act antagonistically...
Summary Understanding how flowers develop from undifferentiated stem cells has occupied developmental biologists for decades. Key to unraveling this process is a detailed knowledge of the global regulatory hierarchies that control transitions, cell differentiation and organ growth. These may be deduced gene perturbation experiments, which determine effects on expression after specific disruption gene. Here, we tested experimental strategies experiments during Arabidopsis thaliana flower...
A three-dimensional structure comparison between the dimeric regulatory serine-binding domain of Escherichia coli d-3-phosphoglycerate dehydrogenase [Schuller, D. J., Grant, G. A., and Banaszak, L. J. (1995) Nat. Struct. Biol. 2, 69−76] E. threonine deaminase [Gallagher, T., Gilliland, L., Xiao, G., Zondlo, Fisher, K. E., Chinchilla, D., Eisenstein, (1998) Structure 6, 465−475] led us to make hypothesis that could have two binding sites per monomer. To test this about corresponding plant...
A 4 glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) was purified from the green alga Chlamydomonas reinhardtii and also overexpressed in Escherichia coli . Both tetramers of recombinant native GAPDH were characterized for first time. The pH optimum both enzymes close to 7.8. p K s residues involved catalysis indicate that a cysteine histidine may take part by chloroplast GAPDH, as is case glycolytic GAPDH. Native show Michaelis–Menten kinetics with respect their cofactors, NADH NADPH,...
The activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) embedded in the phosphoribulokinase (PRK)·GAPDH·CP12 complex was increased 2–3-fold by reducing agents. This occurred interaction with PRK as cysteinyl sulfhydryls (4 SH/subunit) GAPDH within were unchanged whatever redox state complex. But isolated not activated. Alkylation plus mass spectrometry also showed that had one disulfide bridge and three SH groups per monomer active oxidized Reduction disrupted this to give 2 more a...
The 8.5 kDa chloroplast protein CP12 is essential for assembly of the phosphoribulokinase/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) complex from Chlamydomonas reinhardtii. After reduction this with thioredoxin, phosphoribulokinase released but remains tightly associated GAPDH and downregulates its NADPH-dependent activity. We show that only incubation reduced thioredoxin substrate 1,3-bisphosphoglycerate leads to dissociation GAPDH/CP12 complex. Consequently, a significant twofold...
In plants, the protein RPM1-INTERACTING PROTEIN4 (RIN4) is a central regulator of both pattern-triggered immunity and effector-triggered immunity. RIN4 targeted by several effectors, including