ceramide/arabidopsis thaliana

The bioactive lipid ceramide is produced by the enzyme ceramide synthase, which exists in several isoforms in most eukaryotic organisms. Here, we investigated functional differences between the three ceramide synthase isoforms in Arabidopsis thaliana. The biochemical properties of the three ceramide

A hyper-osmotically sensitive mutant of Arabidopsis thaliana, designated hos3-1 (high expression of osmotically responsive genes), was identified based on its hyper-luminescence of RD29A:LUC promoter fusion plants upon treatment with NaCl and ABA. These responses implicate the disrupted gene as a

Arabidopsis thaliana plants that lack ceramide kinase, encoded by ACCELERATED CELL DEATH5 (ACD5), display spontaneous programmed cell death late in development and accumulate substrates of ACD5. Here, we compared ceramide accumulation kinetics, defense responses, ultrastructural features, and sites

Sphingolipids act as structural components of cellular membranes and as signals in a variety of plant developmental processes and defense responses, including programmed cell death. Recent studies have uncovered an interplay between abiotic or biotic stress and programmed cell death. In a previous

Two homologous plant-specific Arabidopsis thaliana genes, RGXT1 and RGXT2, belong to a new family of glycosyltransferases (CAZy GT-family-77) and encode cell wall (1,3)-alpha-d-xylosyltransferases. The deduced amino acid sequences contain single transmembrane domains near the N terminus, indicative

Ceramide synthases catalyze an N-acyltransferase reaction using fatty acyl-coenzyme A (CoA) and long-chain base (LCB) substrates to form the sphingolipid ceramide backbone and are targets for inhibition by the mycotoxin fumonisin B1 (FB1). Arabidopsis (Arabidopsis thaliana) contains three genes

Ca(2+) is an important second messenger in plant signal transduction pathways regulating stress-induced gene expression. Functional analysis of plant proteins containing Ca(2+)-binding domains (C2 domains) will help us understand the mechanisms behind the role of transcriptional regulators in the

Chilling triggers rapid molecular responses that permit the maintenance of plant cell homeostasis and plant adaptation. Recent data showed that nitric oxide (NO) is involved in plant acclimation and tolerance to cold. The participation of NO in the early transduction of the cold signal in

Sphingolipid synthesis is tightly regulated in eukaryotes. This regulation in plants ensures sufficient sphingolipids to support growth while limiting the accumulation of sphingolipid metabolites that induce programmed cell death. Serine palmitoyltransferase (SPT) catalyzes the first step in

Changes in sphingolipids have been associated with profound effects in cell fate and development in both plants and animals. Sphingolipids as a group consist of a large number of different compound classes of which numerous individual species may vary in response to environmental stimuli to affect

l-myo-inositol 1-phosphate synthase (MIPS; EC 5.5.1.4) catalyzes the rate-limiting step in the synthesis of myo-inositol, a critical compound in the cell. Plants contain multiple MIPS genes, which encode highly similar enzymes. We characterized the expression patterns of the three MIPS genes in

A processive diacylglycerol glucosyltransferase has recently been identified from Bacillus subtilis [Jorasch, P., Wolter, F.P., Zähringer, U., and Heinz, E. (1998) Mol. Microbiol. 29, 419-430]. Now we report the cloning and characterization of two other genes coding for diacylglycerol

Plant cells undergoing programmed cell death (PCD) at late stages typically show chromatin condensation and endonucleolytic cleavage prior to obvious membrane or organelle ultrastructural changes. To investigate possible early PCD-associated events, we used microscopic observations and flow

Sphingolipids are important membrane components and also regulate cell proliferation and apoptosis. We detected a fast increase of the free sphingobase t18:0 (phytosphinganine) in Arabidopsis leaves after inoculation with an avirulent strain of the bacterial pathogen Pseudomonas syringae pathovar

Serine palmitoyltransferase (SPT), a pyridoxyl-5'-phosphate-dependent enzyme, catalyzes the first and rate-limiting step in sphingolipid biosynthesis. In humans and yeast, orosomucoid proteins (ORMs) negatively regulate SPT and thus play an important role in maintaining sphingolipid levels. Despite