scholarly journals Identification of the Calmodulin-dependent NAD+ kinase sustaining the elicitor-induced oxidative burst in plants

2019 ◽  
Author(s):  
Elisa Dell’ Aglio ◽  
Cécile Giustini ◽  
Alexandra Kraut ◽  
Yohann Couté ◽  
Christian Mazars ◽  
...  
Keyword(s):  
Plant Physiology ◽  
Oxidative Burst ◽  
Kinase Activity ◽  
Calcium Signalling ◽  
Type Ii ◽  
Nad Kinase ◽  
Metabolic Processes ◽  
Living Organisms ◽  
Related Proteins ◽  
Bacterial Type

AbstractNADP(H) is an essential cofactor ofmultiple metabolic processes in all living organisms. While NADP+ production in plants has long been known to involve a Calmodulin (CaM)/Ca2+-dependent NAD+ kinase, the nature of the enzyme catalyzing this activity has remained enigmatic, as well as its role in plant physiology. Here, we identify an Arabidopsis P-loop ATPase (Atlg04280) with a bacterial type II zeta toxin domain, that catalyzes NADP+ production upon binding of CaM/Ca2+ to a domain located in its N-terminal region. The encoded protein (NADKc-1) is associated with the mitochondria and amplifies the elicitor-induced oxidative burst in Arabidopsis leaves representing the missing link between calcium signalling and metabolism in the response to pathogen elicitor. By analysis of various plants and algae, we show that NADKc is well conserved in the plant lineage and present in basal plants. Our data allows proposing that the CaM-dependent NAD kinase activity is only found in photosynthetic species carrying NADKc-1 related proteins, which would represent the only proteins harboring CaM-dependent NAD kinase activity in plants and algae.

Proline metabolism and NAD kinase activity in soybean calli during short- and long-term exposures to light and NaCl

1997 ◽  
Vol 39 (1) ◽  
pp. 1-9 ◽  
Author(s):  
G. Guerrier ◽  
O. Delumeau ◽  
M. Renard ◽  
D. Laval-Martin
Keyword(s):  
Kinase Activity ◽  
Proline Metabolism ◽  
Nad Kinase ◽  
Short And Long Term

scholarly journals Cellulosomal Scaffoldin-Like Proteins fromRuminococcus flavefaciens

2001 ◽  
Vol 183 (6) ◽  
pp. 1945-1953 ◽  
Author(s):  
Shi-You Ding ◽  
Marco T. Rincon ◽  
Raphael Lamed ◽  
Jennifer C. Martin ◽  
Sheila I. McCrae ◽  
...  
Keyword(s):  
Direct Interaction ◽  
Rumen Bacterium ◽  
Type I ◽  
Gene Products ◽  
Type Ii ◽  
Direct Demonstration ◽  
Anchoring Protein ◽  
Domain Of Unknown Function ◽  
Signature Sequences ◽  
Related Proteins

ABSTRACT Two tandem cellulosome-associated genes were identified in the cellulolytic rumen bacterium, Ruminococcus flavefaciens. The deduced gene products represent multimodular scaffoldin-related proteins (termed ScaA and ScaB), both of which include several copies of explicit cellulosome signature sequences. The scaB gene was completely sequenced, and its upstream neighbor scaAwas partially sequenced. The sequenced portion of scaAcontains repeating cohesin modules and a C-terminal dockerin domain. ScaB contains seven relatively divergent cohesin modules, two extremely long T-rich linkers, and a C-terminal domain of unknown function. Collectively, the cohesins of ScaA and ScaB are phylogenetically distinct from the previously described type I and type II cohesins, and we propose that they define a new group, which we designated here type III cohesins. Selected modules from both genes were overexpressed inEscherichia coli, and the recombinant proteins were used as probes in affinity-blotting experiments. The results strongly indicate that ScaA serves as a cellulosomal scaffoldin-like protein for severalR. flavefaciens enzymes. The data are supported by the direct interaction of a recombinant ScaA cohesin with an expressed dockerin-containing enzyme construct from the same bacterium. The evidence also demonstrates that the ScaA dockerin binds to a specialized cohesin(s) on ScaB, suggesting that ScaB may act as an anchoring protein, linked either directly or indirectly to the bacterial cell surface. This study is the first direct demonstration in a cellulolytic rumen bacterium of a cellulosome system, mediated by distinctive cohesin-dockerin interactions.

scholarly journals A developmental biologist’s journey to rediscover the Zen of plant physiology

F1000Research ◽  
2015 ◽  
Vol 4 ◽  
pp. 264 ◽  
Author(s):  
José R. Dinneny
Keyword(s):  
Plant Physiology ◽  
Human Population ◽  
Holistic Approach ◽  
Normal Function ◽  
Plant Biology ◽  
Form And Function ◽  
Adaptive Mechanisms ◽  
Basic Concepts ◽  
Living Organisms ◽  
And Function

Physiology, which is often viewed as a field of study distinct from development, is technically defined as the branch of biology that explores the normal function of living organisms and their parts. Because plants normally develop continuously throughout their life, plant physiology actually encompasses all developmental processes. Viewing plant biology from a physiologist’s perspective is an attempt to understand the interconnectedness of development, form, and function in the context of multidimensional complexity in the environment. To meet the needs of an expanding human population and a degrading environment, we must understand the adaptive mechanisms that plants use to acclimate to environmental change, and this will require a more holistic approach than is used by current molecular studies. Grand challenges for studies on plant physiology require a more sophisticated understanding of the environment that plants grow in, which is likely to be at least as complex as the plant itself. Moving the lab to the field and using the field for inspiration in the lab need to be expressly promoted by the community as we work to apply the basic concepts learned through reductionist approaches toward a more integrated and realistic understanding of the plant.

scholarly journals Engineered Biosynthesis of a Novel Amidated Polyketide, Using the Malonamyl-Specific Initiation Module from the Oxytetracycline Polyketide Synthase

2006 ◽  
Vol 72 (4) ◽  
pp. 2573-2580 ◽  
Author(s):  
Wenjun Zhang ◽  
Brian D. Ames ◽  
Shiou-Chuan Tsai ◽  
Yi Tang
Keyword(s):  
Polyketide Synthase ◽  
Major Product ◽  
Polyketide Synthases ◽  
Type Ii ◽  
Streptomyces Rimosus ◽  
Aromatic Polyketides ◽  
Starter Unit ◽  
Necessary And Sufficient ◽  
Bacterial Type

ABSTRACT Tetracyclines are aromatic polyketides biosynthesized by bacterial type II polyketide synthases (PKSs). Understanding the biochemistry of tetracycline PKSs is an important step toward the rational and combinatorial manipulation of tetracycline biosynthesis. To this end, we have sequenced the gene cluster of oxytetracycline (oxy and otc genes) PKS genes from Streptomyces rimosus. Sequence analysis revealed a total of 21 genes between the otrA and otrB resistance genes. We hypothesized that an amidotransferase, OxyD, synthesizes the malonamate starter unit that is a universal building block for tetracycline compounds. In vivo reconstitution using strain CH999 revealed that the minimal PKS and OxyD are necessary and sufficient for the biosynthesis of amidated polyketides. A novel alkaloid (WJ35, or compound 2) was synthesized as the major product when the oxy-encoded minimal PKS, the C-9 ketoreductase (OxyJ), and OxyD were coexpressed in CH999. WJ35 is an isoquinolone compound derived from an amidated decaketide backbone and cyclized with novel regioselectivity. The expression of OxyD with a heterologous minimal PKS did not afford similarly amidated polyketides, suggesting that the oxy-encoded minimal PKS possesses novel starter unit specificity.

Nuclear localization of phosphatidylinositol 4-kinase β

2002 ◽  
Vol 115 (8) ◽  
pp. 1769-1775 ◽  
Author(s):  
Petra de Graaf ◽  
Elsa E. Klapisz ◽  
Thomas K. F. Schulz ◽  
Alfons F. M. Cremers ◽  
Arie J. Verkleij ◽  
...  
Keyword(s):  
Nuclear Export ◽  
Kinase Activity ◽  
Insoluble Fraction ◽  
Type Ii ◽  
3T3 Cells ◽  
Type Iii ◽  
Pore Complexes ◽  
Phosphatidylinositol 4 ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

Whereas most phosphatidylinositol 4-kinase (PtdIns 4-kinase) activity is localized in the cytoplasm, PtdIns 4-kinase activity has also been detected in membranedepleted nuclei of rat liver and mouse NIH 3T3 cells. Here we have characterized the PtdIns 4-kinase that is present in nuclei from NIH 3T3 cells. Both type II and type III PtdIns 4-kinase activity were observed in the detergent-insoluble fraction of NIH 3T3 cells. Dissection of this fraction into cytoplasmic actin filaments and nuclear lamina-pore complexes revealed that the actin filament fraction contains solely type II PtdIns 4-kinase,whereas lamina-pore complexes contain type III PtdIns 4-kinase activity. Using specific antibodies, the nuclear PtdIns 4-kinase was identified as PtdIns 4-kinase β. Inhibition of nuclear export by leptomycin B resulted in an accumulation of PtdIns 4-kinase β in the nucleus. These data demonstrate that PtdIns 4-kinase β is present in the nuclei of NIH 3T3 fibroblasts,suggesting a specific function for this kinase in nuclear processes.

4. The burning issue: molecules and energy

2003 ◽  
pp. 70-93
Author(s):  
Philip Ball
Keyword(s):  
Citric Acid ◽  
Chemical Reactions ◽  
Citric Acid Cycle ◽  
Living Cells ◽  
Metabolic Processes ◽  
Acid Cycle ◽  
Cellular Life ◽  
Metabolic Reactions ◽  
Molecular Reactions ◽  
Living Organisms

‘The burning issue: molecules and energy’ describes how energy can be transferred through molecular reactions. Metabolic processes are the foundation of cellular life. All chemical reactions increase entropy (or disorder), but living cells maintain their order by carefully controlling metabolic reactions. In living organisms glucose is broken down into pyruvate through glycolysis. Pyruvate then enters the citric acid cycle, which is a series of reactions that generate electrons which generate ATP — the cell's ‘fuel’. Many scientists, most notably Alfred Nobel, have sought to develop molecules which contain huge amounts of energy safely. These molecules can be used to build civilization — or destroy life.

Causal Relationships among Metabolic Circadian Rhythms in Lemna

1984 ◽  
Vol 39 (1-2) ◽  
pp. 73-84 ◽  
Author(s):  
Ken Goto
Keyword(s):  
Circadian Rhythms ◽  
Kinase Activity ◽  
Continuous Light ◽  
Mirror Image ◽  
Nad Kinase ◽  
Long Day ◽  
Level Of Activity ◽  
Night Period

Abstract Biochemical aspects of circadian rhythms were studied using a long-day duckweed, Lemna gibba G3 cultured in short day condition (9 h light at 3800 lux followed by 15 h darkness), which was transferred in continuous light (LL) at the end (LL 0) of the last night period. With such a system I have previously reported a rhythm of affinity for NAD+ of cytoplasmic NAD - dependent glyceraldehyde 3-phosphate dehydrogenase (Cyt-NAD -GPD ) 180° out of phase with that of affinity for NADP+ of chloroplastic NADP-dependent GPD (Chl-NADP-GPD ) and that NADP+ could increase in vitro the affinity for NADP+ of Chl-NADP-GPD . I report here that NADP+ can decrease in vitro the affinity for NAD+ of Cyt-NAD -GPD as well, and furthermore, that the in vivo level of NADP+ oscillates in phase with the rhythm of the affinity for NADP+ of Chl-NADP-GPD. Moreover, I found the existence of mirror-image circadian rhythms, of comparable am plitudes, of in vivo levels of NAD+ + NADH (total NAD) (with peaks, as the ones of Cyt-NAD - GPD. at LL 0 and 24) and of NADP+ + NADPH (total NADP) (with peaks, as the ones of Chl-NADP-GPD, at LL 12 and 36). Consequently, a circadian rhythm in the rate of net in vivo production of total NADP (or NAD) might be expected 90° in advance of that in the level of total NADP (or NAD). Indeed. I found oscillations in the activities of NAD kinase and of NADP phosphatase with peaks occurring, respectively, at LL 6 and at LL 18. Moreover, in vitro treatments with EGTA (a Ca2+-chelator), chlorpromazine and W7 (both inhibitors of calmodulin) were able to both inhibit NAD kinase from its highest level of activity to its minimal one and activate NADP phosphatase from its lowest level of activity to its maximal one. I conclude, therefore, that the in vivo level of Ca2+-calmodulin could oscillate in phase with the rhythm of NAD kinase activity and induce the mirror-image circadian rhythms of activities of NAD kinase and of NADP phosphatase. I propose that the control sequence among the several circadian rhythms I studied could start with changes in Ca2+-calmodulin, then proceed through oscillations in NAD kinase and NADP phosphatase activities, leading to changes in NAD+, NADP+, and NADPH levels, which would themselves induce the Chl-NADP-GPD and Cyt-NAD -GPD rhythms.

Sign in / Sign up

Export Citation Format

Share Document