Halfway between bacteria and tree
How the protein transport machinery in the chloroplasts of higher plants developed Moss Physcomitrella patens is an evolutionary intermediate stage
Together with colleagues from Sweden, RUB researchers have studied how the protein transport system of bacteria developed over time to form the system in the chloroplasts of higher plants. They explored the so-called signal recognition particles (SRP) and their receptors. Bioinformatic and biochemical analyses revealed that the moss Physcomitrella patens has evolutionarily old and new components of the SRP system, and thus represents an intermediate stage in the development from the bacterial transport system to the chloroplast system in higher plants. The international team led by Prof. Dr. Danja Schnemann and Dr. Chantal Trger from the Working Group Molecular Biology of Plant Organelles at the Ruhr-Universitt reported in the journal The Plant Cell.
The SRP system guides new proteins to their place of work
In the cell fluid, a special transport machinery conveys proteins from their origin to their place of work, for example in the cell membrane. The decisive factor is the so-called SRP system. It binds itself to the protein to be transported, travels with it to the cell membrane and interacts there with the SRP receptor (FtsY). If the SRP system binds to the receptor, cleavage of the energy storage molecule GTP triggers further processes which ultimately anchor the protein in the membrane.
From cyanobacterium to chloroplast
In the cell fluid of bacteria, animals and plants, the SRP system consists of two components: the protein SRP54 and the ribonucleic acid SRP RNA. Several years ago, researchers found that the chloroplasts of higher plants, i.e. the photosynthetically active cell components, possess their own SRP system. It is very different from the system of the cell fluid because it has no SRP
|Contact: Prof. Dr. Danja Schnemann|