Background: Regulatory adjustments to acute and chronic temperature changes are highly important for aquatic ectotherms because temperature affects their metabolic rate as well as the already low oxygen concentration in water, which can upset their energy balance. This also applies to severe changes in food supply. Thus, we studied on a molecular level (transcriptomics and/or proteomics) the immediate responses to heat stress and starvation and the acclimation to different temperatures in two clonal isolates of the model microcrustacean Daphnia pulex from more or less stressful environments, which showed a higher (clone M) or lower (clone G) tolerance to heat and starvation.
View Article and Find Full Text PDFThe absolute amount of plastocyanin (PC), ferredoxin-NADP-oxidoreductase (FNR), hydrogenase (HYDA1), and ferredoxin 5 (FDX5) were quantified in aerobic and anaerobic Chlamydomonas reinhardtii whole cells using purified (recombinant) proteins as internal standards in a mass spectrometric approach. Quantified protein amounts were related to the estimated amount of PSI. The ratios of PC to FNR to HYDA1 to FDX5 in aerobic cells were determined to be 1.
View Article and Find Full Text PDFThe biosynthesis of multiple secondary metabolites in the phytopathogenic ascomycete Fusarium fujikuroi is strongly affected by nitrogen availability. Here, we present the first genome-wide transcriptome and proteome analysis that compared the wild type and deletion mutants of the two major nitrogen regulators AreA and AreB. We show that AreB acts not simply as an antagonist of AreA counteracting the expression of AreA target genes as suggested based on the yeast model.
View Article and Find Full Text PDFComp Biochem Physiol B Biochem Mol Biol
December 2016
Elevated temperatures considerably challenge aquatic invertebrates, and enhanced energy metabolism and protein turnover require adjustments of digestion. In Daphnia, the serine proteases chymotrypsin and trypsin represent the major proteolytic enzymes. Daphnia pulex acclimated to different temperature conditions or subjected to acute heat stress showed increased expression level of serine proteases with rising temperatures.
View Article and Find Full Text PDFP-proteins are structural phloem proteins discussed to be involved in the rapid sealing of injured sieve elements. P-proteins are found in all dicotyledonous and some monocotyledonous plants, but additional crystalloid P-proteins, known as forisomes, have evolved solely in the Fabaceae. Both types are encoded by members of the sieve element occlusion (SEO) gene family, which comprises seven phylogenetic subgroups.
View Article and Find Full Text PDFThe unicellular flagellated green alga Chlamydomonas reinhardtii has emerged as a model organism for the study of a variety of cellular processes. Posttranslational control via protein phosphorylation plays a key role in signal transduction, regulation of gene expression, and control of metabolism. Thus, analysis of the phosphoproteome of C.
View Article and Find Full Text PDFJ-domain cochaperones confer functional specificity to their heat shock protein (HSP)70 partner by recruiting it to specific substrate proteins. To gain insight into the functions of plastidic HSP70s, we searched in Chlamydomonas databases for expressed sequence tags that potentially encode chloroplast-targeted J-domain cochaperones. Two such cDNAs were found: the encoded J-domain proteins were named chloroplast DnaJ homolog 1 and 2 (CDJ1 and CDJ2).
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