Nitrogen is an essential macronutrient for plant growth and development. Inorganic nitrogen and its assimilation products control various metabolic, physiological and developmental processes. Although the transcriptional responses induced by nitrogen have been extensively studied in the past, our work here focused on the discovery of candidate proteins for regulatory events that are complementa...

The influence of glutamate dehydrogenase activity on nitrogen regulation in Corynebacterium glutamicum was investigated. As shown by RNA hybridization experiments deletion of the gdh gene results in a rearrangement of nitrogen metabolism. Even when sufficiently supplied with nitrogen sources, a gdh deletion strain showed the typical nitrogen starvation response of C. glutamicum. These changes i...

The biosynthesis of asparaginase II in Saccharomyces cerevisiae is subject to nitrogen catabolite repression. In the present study we examined the physiological effects of glutamate auxotrophy on cellular metabolism and on the nitrogen catabolite repression of asparaginase II. Glutamate auxotrophic cells, incubated without a glutamate supplement, had a diminished internal pool of alpha-ketoglut...

Obesity has dramatically increased in prevalence, making it essential to understand its accompanying metabolic changes. Modeling diet-induced obesity in Drosophila melanogaster (fruit flies), we elucidated transcriptional and metabolic changes in w (1118) flies on a high-fat diet (HFD). Mass spectrometry-based metabolomics revealed altered fatty acid, amino acid, and carbohydrate metabolism wit...

While nitrogen availability is known to limit primary production in large parts of the ocean, vitamin starvation amongst eukaryotic phytoplankton is becoming increasingly recognized as an oceanographically relevant phenomenon. Cobalamin (B(12)) and thiamine (B(1)) auxotrophy are widespread throughout eukaryotic phytoplankton, with over 50% of cultured isolates requiring B(12) and 20% requiring ...

In this review, we consider the exchange of nutrients between the host plant and the bacterial microsymbiont in nitrogen-fixing legume root nodules. During nodule formation, the host tissues and the bacterial microsymbiont develop in response to each other to form a specialized tissue that maintains an environment where nitrogen fixation can occur (Brewin, 2004; Mergaert et al., 2006; Prell and...

NAD(+) plays central roles in energy metabolism as redox carrier. Recent research has identified important signalling functions of NAD(+) that involve its consumption. Although NAD(+) is synthesized mainly in the cytosol, nucleus and mitochondria, it has been detected also in vesicular and extracellular compartments. Three protein families that consume NAD(+) in signalling reactions have been c...

A key component to the success of Mycobacterium tuberculosis as a pathogen is the ability to sense and adapt metabolically to the diverse range of conditions encountered in vivo, such as oxygen tension, environmental pH and nutrient availability. Although nitrogen is an essential nutrient for every organism, little is known about the genes and pathways responsible for nitrogen assimilation in M...

Thirty patients suffering from chronic kidney disease were examined for urinary, fecal and total plasma porphyrins. Twenty patients had nitrogen retention whereas the remaining ten patients displayed normal values. Urinary coproporphyrin excretion and total plasma porphyrin levels were comparatively less pronounced in patients with nitrogen retention. Such changes in porphyrin metabolism could ...