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Calcium-dependent protein kinases (CDPKs) are found in various subcellular localizations, which suggests that this family of serine/threonine kinases may be involved in multiple signal transduction pathways. CDPKs are believed to be involved in the response of plants to low temperatures, but the precise role in the signal transduction pathway is largely(More)
Temperature sensing is essential for the survival of living cells. A major challenge is to understand how a biological thermometer processes thermal information to optimize cellular functions. Using structural and biochemical approaches, we show that the thermosensitive histidine kinase, DesK, from Bacillus subtilis is cold-activated through specific(More)
Glycosyltransferases (GTs) are a ubiquitous group of enzymes that catalyze the transfer of sugar moieties from activated donor molecules to specific acceptor molecules, forming glycosidic bonds. Nucleotide-sugars, lipid phosphate sugars and phosphate sugars can act as activated donor molecules while acceptor substrates involve carbohydrates, proteins,(More)
Plant mitochondria include gamma-type carbonic anhydrases (gammaCAs) of unknown function. In Arabidopsis, the gammaCAs form a gene family of five members which all are attached to the NADH dehydrogenase complex (complex I) of the respiratory chain. Here we report a functional analysis of gamma carbonic anhydrase 2 (CA2). The gene encoding CA2 is(More)
Calcium-dependent protein kinases (CDPKs), the most abundant serine/threonine kinases in plants, are found in various subcellular localizations, which suggests that this family of kinases may be involved in multiple signal transduction pathways. A complete analysis to try to understand the molecular basis of the presence of CDPKs in various localizations in(More)
Recent findings demonstrate that alkaline/neutral invertases (A/N-Invs), enzymes that catalyze the breakdown of sucrose into glucose and fructose, are essential proteins in plant life. The fact that different isoforms are present in multiple locations makes them candidates for the coordination of metabolic processes. In the present study, we functionally(More)
Frataxin is a mitochondrial protein that is conserved throughout evolution. In yeast and mammals, frataxin is essential for cellular iron (Fe) homeostasis and survival during oxidative stress. In plants, frataxin deficiency causes increased reactive oxygen species (ROS) production and high sensitivity to oxidative stress. In this work we show that a(More)
Thermosensors are ubiquitous integral membrane proteins found in all kinds of life. They are involved in many physiological roles, including membrane remodeling, chemotaxis, touch, and pain [1-3], but, the mechanism by which their transmembrane (TM) domains transmit temperature signals is largely unknown. The histidine kinase DesK from Bacillus subtilis is(More)
Higher plants and cyanobacteria metabolize sucrose (Suc) by a similar set of enzymes. Suc synthase (SuS, A/UDP-glucose: d-fructose 2-α-d-glucosyl transferase) catalyzes a reversible reaction. However, it is in the cleavage of Suc that this enzyme plays an important role in vivo, providing sugar nucleotides for polysaccharide biosynthesis. In cyanobacteria,(More)
Glycogen and starch, the major storage carbohydrate in most living organisms, result mainly from the action of starch or glycogen synthases (SS or GS, respectively, EC 2.4.1.21). SSIII from Arabidopsis thaliana is an SS isoform with a particular modular organization: the C-terminal highly conserved glycosyltransferase domain is preceded by a unique specific(More)