Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

HU Research Enables Better Understanding of Chlorophyll Synthesis

04.04.2018

Research team discovers previously unknown function of chloroplast chaperone.

Photosynthesis is an essential process for the existence of all organisms on our planet, in which sunlight is converted into biochemical energy. The pigment chlorophyll plays a key role in this process. A team of researchers at the Humboldt University of Berlin (HU) has now come up with new findings on how the synthesis of chlorophyll is regulated.


Sunlight is absorbed by the pigment chlorophyll and converted into biochemical energy through photosynthesis. The chlorophyll is integrated into light-harvesting chlorophyll-binding proteins (LHCPs) in the plant organelle chloroplast.

Once these LHCPs have been synthesised in the zytoplasma and imported into the chloroplasts, they are transported onwards to their destination by the chloroplast signal recognition particles cpSRP43 and cpSRP54, where they are incorporated into the thylakoid membranes in which the photosynthetic processes occur. The chlorophylls are inserted while the LHCPs are being integrated into the membranes.

In order to ensure that sufficient amounts of chlorophyll are always available for the photosynthesis, the chlorophyll synthesis must be effectively coordinated with the provision of the LHCPs. The rate-limiting step of the chlorophyll synthesis is carried out with glutamyl-tRNA reductase (GluTR) — the first enzyme of the metabolic pathway.

GluTR then ensures the required quantity of 5-aminolevulinic acid, the building block of all chlorophylls. The activity and stability of GluTR is regulated in a very diverse way. A research team at HU recently investigated exactly how this process is regulated.

Dr Peng Wang, a member of Prof Bernhard Grimm’s plant physiology work group, discovered that cpSRP43 exerts chaperone properties on the enzyme GluTR. More specifically, it supports the enzyme in the correct convolution and in the assembly in complexes.

The cpSRP43 interacts with GluTR on “aggregation-prone motifs” (i.e. protein areas which are particularly prone to aggregate formation) and prevents the aggregation of the GluTR. This promotes the stability of the GluTR and helps avoid its inactivation.

Thus, in their recently published study, the researchers describe an additional function of the chaperone cpSRP43 in a new type of posttranslational control mechanism of the GluTR. Besides the transportation of the LHCPs within the chloroplasts, by stabilising GluTR, cpSRP43 also ensures the appropriate synthesis of the 5-aminolevulinic acid and thus the suitable amount of chlorophylls throughout continuously changing environmental conditions.

The work group assumes that, thanks to the chaperone function, cpSRP43 now enables a linking of the tailor-made rates of the LHCP transportation as well as of the chlorophyll synthesis.

The complete study was published under the title “Chloroplast SRP43 acts as a chaperone for glutamyl-tRNA reductase, the rate-limiting enzyme in tetrapyrrole biosynthesis” in the journal Proceedings of the National Academy of Sciences of the U.S.A.

Further information
http://www.pnas.org/content/early/2018/03/21/1719645115
https://www.biologie.hu-berlin.de

Contact
Prof Bernhard Grimm
Institute for Biology
Phone: 030 2093-46312
bernhard.grimm@rz.hu-berlin.de

Contact
Hans-Christoph Keller
Spokesperson of Humboldt University of Berlin
PR department head
Phone: 030 2093-2332
hans-christoph.keller@hu-berlin.de

Boris Nitzsche | idw - Informationsdienst Wissenschaft
Further information:
http://www.hu-berlin.de/

More articles from Life Sciences:

nachricht If Machines Could Smell ...
19.07.2019 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Algae-killing viruses spur nutrient recycling in oceans
18.07.2019 | Rutgers University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Better thermal conductivity by adjusting the arrangement of atoms

Adjusting the thermal conductivity of materials is one of the challenges nanoscience is currently facing. Together with colleagues from the Netherlands and Spain, researchers from the University of Basel have shown that the atomic vibrations that determine heat generation in nanowires can be controlled through the arrangement of atoms alone. The scientists will publish the results shortly in the journal Nano Letters.

In the electronics and computer industry, components are becoming ever smaller and more powerful. However, there are problems with the heat generation. It is...

Im Focus: First-ever visualizations of electrical gating effects on electronic structure

Scientists have visualised the electronic structure in a microelectronic device for the first time, opening up opportunities for finely-tuned high performance electronic devices.

Physicists from the University of Warwick and the University of Washington have developed a technique to measure the energy and momentum of electrons in...

Im Focus: Megakaryocytes act as „bouncers“ restraining cell migration in the bone marrow

Scientists at the University Würzburg and University Hospital of Würzburg found that megakaryocytes act as “bouncers” and thus modulate bone marrow niche properties and cell migration dynamics. The study was published in July in the Journal “Haematologica”.

Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red...

Im Focus: Artificial neural network resolves puzzles from condensed matter physics: Which is the perfect quantum theory?

For some phenomena in quantum many-body physics several competing theories exist. But which of them describes a quantum phenomenon best? A team of researchers from the Technical University of Munich (TUM) and Harvard University in the United States has now successfully deployed artificial neural networks for image analysis of quantum systems.

Is that a dog or a cat? Such a classification is a prime example of machine learning: artificial neural networks can be trained to analyze images by looking...

Im Focus: Extremely hard yet metallically conductive: Bayreuth researchers develop novel material with high-tech prospects

An international research group led by scientists from the University of Bayreuth has produced a previously unknown material: Rhenium nitride pernitride. Thanks to combining properties that were previously considered incompatible, it looks set to become highly attractive for technological applications. Indeed, it is a super-hard metallic conductor that can withstand extremely high pressures like a diamond. A process now developed in Bayreuth opens up the possibility of producing rhenium nitride pernitride and other technologically interesting materials in sufficiently large quantity for their properties characterisation. The new findings are presented in "Nature Communications".

The possibility of finding a compound that was metallically conductive, super-hard, and ultra-incompressible was long considered unlikely in science. It was...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on UV LED Technologies & Applications – ICULTA 2020 | Call for Abstracts

24.06.2019 | Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

 
Latest News

Heat flow through single molecules detected

19.07.2019 | Physics and Astronomy

Heat transport through single molecules

19.07.2019 | Physics and Astronomy

Welcome Committee for Comets

19.07.2019 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>