Fusion protein controls design of photosynthesis platform

Fusion protein controls design of photosynthesis platform
An IM30 ring docks with internal membranes. In the background is part of an image of a blue-green alga prepared using an electron microscope. A 3D model of the IM30 ring can be seen in the foreground. The images are not to scale. Credit: Dirk Schneider, Jürgen Markl

Chloroplasts are the solar cells of plants and green algae. In a process called photosynthesis, light energy is used to produce biochemical energy and the oxygen we breathe. Thus, photosynthesis is one of the most important biological processes on the planet. A central part of photosynthesis takes place in a specialized structure within chloroplasts, the thylakoid membrane system. Despite its apparent important function, until now it was not clear how this specialized internal membrane system is actually formed. In a collaborative project, researchers at Johannes Gutenberg University Mainz (JGU) in Germany have now identified how this membrane is generated. According to their findings, a protein called IM30 plays a major role by triggering the fusion of internal membranes. The study elucidating the role of IM30 involved biologists, chemists, biochemists, and biophysicists at Mainz University and the Max Planck Institute for Polymer Research. Their results have recently been published in the journal Nature Communications.

Chloroplasts are organelles found in higher plants and green algae. They contain an internal system, so-called thylakoid membranes, where the key processes of take place. "A detailed understanding of photosynthesis and the associated molecular processes is essential to properly comprehend life on our planet," emphasized Professor Dirk Schneider of the Institute of Pharmaceutical Sciences and Biochemistry at JGU, who coordinated the study. "Despite the significance of the process, we know almost nothing about how these special membranes are formed and maintained." It had not previously been possible to identify a single fusion-mediating protein in photosynthetic cells, even though it was perfectly clear that such proteins have to be involved in the development of thylakoid membranes.

With this in mind, the Mainz-based research team isolated and investigated the protein IM30 from a blue-green alga, which might be classified as a "free-living chloroplast." IM30 - the "IM" stands for "internal membrane" while 30 is its atomic mass (30 kilodaltons) - was first described in the mid-1990s and it was demonstrated that it binds to internal membranes. Thanks to the combined expertise of the teams headed by Professor Dirk Schneider, Professor Jürgen Markl of the JGU Institute of Zoology, and Professor Tobias Weidner of the Max Planck Institute for Polymer Research it has now emerged that IM30 forms a ring structure that specifically interacts with phospholipids of the membranes. "This binding alters the membrane structure and under certain conditions can lead to membrane fusion," explained Schneider. In absence of IM30, thylakoid membranes are noticeably deteriorated, which can subsequently lead to loss of cell viability. The IM30 fusion protein provides a starting point for future research, unraveling new types of membrane fusion mechanisms in chloroplasts and blue-.

The interdisciplinary research project was primarily undertaken by doctoral candidates at the Max Planck Graduate Center (MPGC). The MPGC was founded in June 2009 to support joint projects and shared doctorates at Johannes Gutenberg University Mainz and the Max Planck Institutes for Polymer Research and for Chemistry, both of which are based in Mainz.


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More information: Raoul Hennig et al., IM30 triggers membrane fusion in cyanobacteria and chloroplasts, Nature Communications, 8 May 2015. DOI: 10.1038/ncomms8018
Journal information: Nature Communications

Provided by Universitaet Mainz
Citation: Fusion protein controls design of photosynthesis platform (2015, May 13) retrieved 19 August 2019 from https://phys.org/news/2015-05-fusion-protein-photosynthesis-platform.html
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JVK
May 16, 2015
Excerpt: The study elucidating the role of IM30 involved biologists, chemists, biochemists, and biophysicists…

See also: http://rna-mediat...or-life/

My comments: Any elucidation of facts that link the sun's biological energy from the de novo creation of light-induced amino acids to the creation of proteins and membranes that enable photosynthesis must involve biologists, chemists, biochemists, and biophysicists. Otherwise, the link from RNA-directed DNA methylation and RNA-mediated amino acid substitutions to cell type differentiation in all cells of all individuals of all genera may be lost in the reporting of results from different disciplines or different research groups.

JVK
May 18, 2015
What happened? Did evolutionary theorists and big bang cosmologists finally realize that proteins do not automagically evolve?

Is someone behind the scenes waiting to redefine "evolution" and "mutation" and "big bang" so that they can continue to tout the pseudoscientific nonsense of ridiculous theories even after the fact that the light-induced de novo creation of amino acids has been linked to the creation of the membrane that enables photosynthesis?

http://dx.doi.org...omms8018 Excerpt: "A central role of IM30 in triggering membrane fusion explains the various pleiotropic functions ascribed to IM30 in the past, mainly based on studies using higher plants, algae or cyanobacteria with decreased IM30 contents. Lipid transport24,44, vesicle budding or fission19, protein translocation and insertion29,45,46, membrane modification28,47, as well as biogenesis of photosystems21,30,48 have been ascribed to IM30."

Note: That's biogenesis, not abiogenesis.


JVK
May 18, 2015
Andrew Jones (aka anonymous_9001) thought he knew enough to criticize my review of cell type differentiation. See: Criticisms of the nutrient-dependent pheromone-controlled evolutionary model http://www.ncbi.n...4959329/

See the thesis of a science idiot at http://www.scribd...s#scribd

Excerpt: "...ribozymes have made an interesting niche for themselves in the field of abiogenesis. The evolution of a successful RNA polymerase ribozyme is a lofty goal. While its discovery would not be the be-all and end-all of abiogenesis research, it would represent an important stepping stone between prebiotic chemistry and life. The encapsulation of such a ribozyme is also an important step, as it would enable a system of heredity and evolution through natural selection. Based on progress in current research, it is only a matter of time before that ribozyme is discovered."

JVK
May 18, 2015
See also:
A lighting requirement for life http://rna-mediat...or-life/

Compare what you find on a google search for "RNA mediated" and for "Protein evolution"

If you link what is known about RNA-mediated amino acid substitutions to theories about the evolution of proteins via the conserved molecular mechanisms of biophysically constrained RNA-mediated protein folding during life history transitions of all genera, please tell Eugene Koonin that you have discovered a link to our last universal common ancestor, that his group could not conceptualize.

A universal trend of amino acid gain and loss in protein evolution http://www.nature...306.html

"We cannot conceive of a global external factor that could cause, during this time, parallel evolution of amino acid compositions of proteins in 15 diverse taxa that represent all three domains of life and span a wide range of lifestyles and environments."

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