Tag Archives: transporters

The artificial cell: biology-inspired compartmentalization of chemical function

Royal Society Publishing has recently published a special issue of Interface Focus entitled “The artificial cell: biology-inspired compartmentalization of chemical function”, organised by Paul A Beales, Barbara Ciani and Stephen Mann.

This issue is based on a Royal Society Theo Murphy meeting held on the 26–27 February 2018. The articles reveal the rich diversity of research currently being undertaken in the field of artificial cell design and construction, and highlight the challenges that lie ahead.

The articles are FREE TO ACCESS here.

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Translation Stress Positively Regulates MscL-Dependent Excretion of Cytoplasmic Proteins

Protein translocation is an essential feature of cellular organisms. Bacteria, like all single-cell organisms, interact with their environment by translocation of proteins across their cell membranes via dedicated secretion pathways. Proteins destined for secretion are directed toward the secretion pathways by the presence of specific signal peptides. This study demonstrates that under conditions of both osmotic stress and translation stress, E. coli cells undergo an excretion phenomenon whereby signal peptide-less proteins are translocated across both the inner and outer cell membranes into the extracellular environment. Confirming the presence of alternative translocation/excretion pathways and understanding their function and regulation are thus important for fundamental microbiology and biotechnology. Read more

Identification and utilization of two important transporters: SgvT1 and SgvT2, for griseoviridin and viridogrisein biosynthesis in Streptomyces griseoviridis

Yunchang Xie, Junying Ma, Xiangjing Qin, Qinglian Li and Jianhua Ju

Background

Griseoviridin (GV) and viridogrisein (VG, also referred as etamycin), both biosynthesized by a distinct 105 kb biosynthetic gene cluster (BGC) in Streptomyces griseoviridis NRRL 2427, are a pair of synergistic streptogramin antibiotics and very important in treating infections of many multi-drug resistant microorganisms. Three transporter genes, sgvT1–T3 have been discovered within the 105 kb GV/VG BGC, but the function of these efflux transporters have not been identified. Read more

Pseudomonas stutzeri as an alternative host for membrane proteins

Manuel Sommer, Hao Xie and Hartmut Michel

Background

Studies on membrane proteins are often hampered by insufficient yields of the protein of interest. Several prokaryotic hosts have been tested for their applicability as production platform but still Escherichia coli by far is the one most commonly used. Nevertheless, it has been demonstrated that, in some cases, hosts other than E. coli are more appropriate for certain target proteins. Read more

Naturally occurring transporter protein discovered which boosts rice yield by 50%

In collaboration with researchers at Nanjing Agricultural University, Dr Tony Miller from the John Innes Centre has developed rice crops with an improved ability to manage their own pH levels, enabling them to take up significantly more nitrogen, iron and phosphorous from soil and increase yield by up to 54%.

Rice is a major crop, feeding almost 50% of the world’s population and has retained the ability to survive in changing environmental conditions. The crop is able to thrive in flooded paddy fields – where the soggy, anaerobic conditions favour the availability of ammonium – as well as in much drier, drained soil, where increased oxygen means more nitrate is available. nitrogen fertilizer is a major cost in growing many cereal crops and its overuse has a negative environmental impact.

The nitrogen that all plants need to grow is typically available in the form of nitrate or ammonium ions in the soil, which are taken up by the plant roots. For the plant, getting the right balance of nitrate and ammonium is very important: too much ammonium and plant cells become alkaline; too much nitrate and they become acidic. Either way, upsetting the pH balance means the plant’s enzymes do not work as well, affecting plant health and crop yield.

Together with the partners in Nanjing, China, Dr Miller’s team has been working out how rice plants can maintain pH under these changing environments.

Rice contains a gene called OsNRT2.3, which creates a protein involved in nitrate transport. This one gene makes two slightly different versions of the protein: OsNRT2.3a and OsNRT2.3b. Following tests to determine the role of both versions of the protein, Dr Miller’s team found that OsNRT2.3b is able to switch nitrate transport on or off, depending on the internal pH of the plant cell.

When this ‘b’ protein was overexpressed in rice plants they were better able to buffer themselves against pH changes in their environment. This enabled them to take up much more nitrogen, as well as more iron and phosphorus. These rice plants gave a much higher yield of rice grain (up to 54% more yield), and their nitrogen use efficiency increased by up to 40%.

Dr Miller said: “Now that we know this particular protein found in rice plants can greatly increase nitrogen efficiency and yields, we can begin to produce new varieties of rice and other crops. These findings bring us a significant step closer to being able to produce more of the world’s food with a lower environmental impact.”

This new technology has been patented by PBL, the John Innes Centre’s innovation management company, and has already been licensed to three different companies to develop new varieties of six different crop species.

This study, which will be published in the Proceedings of the National Academy of Sciences USA, was funded by the Biotechnology and Biological Sciences Research Council (BBSRC) and grants from the Chinese Government.

 

The paper “Overexpression of a pH-sensitive nitrate transporter in rice increases crop yields” has been published in the Proceedings of the National Academy of Science www.pnas.org/content/early/2016/06/01/1525184113.full

Full article from BBSRC http://www.bbsrc.ac.uk/news/food-security/2016/160628-pr-protein-discovered-boosts-rice-yield/