The thylakoid lumen, a dynamic part of the photosynthetic process
Research project
The beautiful architecture of the thylakoid network is a distinguishing characteristic of the chloroplast of higher plants. Mature thylakoids are differentiated into cylindrical grana stacks and tubular stroma lamellae that together enclose the continuous luminal compartment.
It is well established that the chloroplast lumen plays an important role in the formation of the thylakoid proton gradient that drives ATP synthesis. Almost nine years ago my group started a systematic study of the luminal content of the thylakoid membrane and was first with the discovery that the chloroplast lumen contained a large number of proteins. This study showed that the luminal chloroplast compartment contained an own specific proteome with several novel protein families.
We performed genome wide bioinformatics prediction of luminal chloroplast proteins, and based on this work we were able to predict that the luminal chloroplast proteome of Arabidopsis consists of 80 proteins. Although, the study of the expression of the luminal chloroplast proteins has clearly changed the model of the chloroplast lumen, the functions of most of the novel luminal proteins are not yet known.
The aim of this proposal is to further develop these studies to gain a more profound understanding of the functions of the luminal proteome. Specific tasks are: 1.Biotic and abiotic stress effects on the lumen content 2. Analysis of function and structure of some specific luminal proteins (TL29, PrxQ) 3. Protein expression in specific photosynthetic mutants The tasks will be addressed by use of 2D-difference gel electrophoresis (DIGE), the use of hydroponically grown plants for full nutrition control, and screening for the gene of interest in random T-DNA insertion databases.