Ammonium induces differential expression of methane and nitrogen metabolism-related genes in Methylocystis sp. strain SC2.

Nitrogen source and concentration are major determinants of methanotrophic activity, but their effect on global gene expression is poorly studied. Methylocystis sp. strain SC2 produces two isozymes of particulate methane monooxygenase.

Massively convergent evolution for ribosomal protein gene content in plastid and mitochondrial genomes.

Plastid and mitochondrial genomes have undergone parallel evolution to encode the same functional set of genes. These encode conserved protein components of the electron transport chain in their respective bioenergetic membranes and genes for the ribosomes that express them. This highly convergent aspect of organelle genome evolution is partly explained by the redox regulation hypothesis, which predicts a separate plastid or mitochondrial location for genes encoding bioenergetic membrane proteins of either photosynthesis or respiration.

Genome analysis coupled with physiological studies reveals a diverse nitrogen metabolism in Methylocystis sp. strain SC2.

Background: Methylocystis sp. strain SC2 can adapt to a wide range of methane concentrations. This is due to the presence of two isozymes of particulate methane monooxygenase exhibiting different methane oxidation kinetics.

"Non-canonical protein-DNA interactions identified by ChIP are not artifacts": response.

Background: Studies of protein association with DNA on a genome wide scale are possible through methods like ChIP-Chip or ChIP-Seq. Massive problems with false positive signals in our own experiments motivated us to revise the standard ChIP-Chip protocol. Analysis of chromosome wide binding of the alternative sigma factor σ³² in Escherichia coli with this new protocol resulted in detection of only a subset of binding sites found in a previous study by Wade and colleagues.

New twist to nuclear import: When two travel together.

Ribosomes are the nanomachines that synthesize all cellular proteins from mRNA templates. In eukaryotes, ribosomes, which are composed of ribosomal proteins and rRNA, are mainly assembled in the nucleus. Thus, ribosomal proteins require a nuclear transport step from their place of synthesis in the cytoplasm to their site of assembly in the nucleus.

An engineered diatom acting like a plasma cell secreting human IgG antibodies with high efficiency.

Background: Although there are many different expression systems for recombinant production of pharmaceutical proteins, many of these suffer from drawbacks such as yield, cost, complexity of purification, and possible contamination with human pathogens. Microalgae have enormous potential for diverse biotechnological applications and currently attract much attention in the biofuel sector. Still underestimated, though, is the idea of using microalgae as solar-fueled expression system for the production of recombinant proteins.

Algae as protein factories: expression of a human antibody and the respective antigen in the diatom Phaeodactylum tricornutum.

Microalgae are thought to offer great potential as expression system for various industrial, therapeutic and diagnostic recombinant proteins as they combine high growth rates with all benefits of eukaryotic expression systems. Moreover, microalgae exhibit a phototrophic lifestyle like land plants, hence protein expression is fuelled by photosynthesis, which is CO(2)-neutral and involves only low production costs. So far, however, research on algal bioreactors for recombinant protein expression is very rare calling for further investigations in this highly promising field.