Membrane Protein Homeostasis and Production

Project leader

Funding source

Swedish Research Council - Vetenskapsrådet (VR)

Project Details

Start date: 01/01/2016
End date: 31/12/2019
Funding: 3150000 SEK


Integral membrane proteins account for ~30% of all open reading frames in sequenced genomes, and they fulfil a wide range of central functions in the cell. However, our knowledge of this important class of proteins is still poor. Thus far, membrane protein biogenesis, quality control and degradation have hardly been studied at a proteome-wide level. Furthermore, functional and structural studies of membrane proteins are still hampered by a lack of reliable and robust production systems. The two main goals of our laboratory are to provide the first global picture of the homeostasis of a membrane proteome, and to create platforms for the efficient production of membrane proteins for functional and structural studies. In all our studies we use Escherichia coli, which is not only one of the best-characterized and accessible model organisms, but also the main workhorse in molecular biology research. The two goals of our laboratory are intimately linked: in depth knowledge of membrane protein homeostasis is essential for creating membrane protein production strains, and studying the effects of membrane protein production gives important clues about membrane protein homeostasis.

Our objectives for the next four years are to:

-i- Identify the substrates of key players in the biogenesis of the E. coli cytoplasmic membrane proteome using in vivo cross-linking and mass spectrometry.

-ii- Determine components involved in the quality control and degradation of membrane proteins in E. coli using genetic screens.

-iii- Isolate E. coli strains with improved membrane protein production characteristics using genetic screens and characterize selected strains.

-iv- Identify the secretory protein production bottlenecks in E. coli using proteomics and genetic engineering. In addition, E. coli producing secretory proteins will be used to identify alternative membrane protein biogenesis pathways.

To achieve these objectives, we request support for two Ph.D. students. One student will work on membrane proteome homeostasis (objectives -i-, -ii- and partially -iv-) and the other on membrane and secretory protein production (objectives -iii- and -iv-). Importantly, E. coli appears to contain the blueprints of membrane protein biogenesis, quality control and degradation pathways present in many pro- and eukaryotic organisms, making it an ideal model system to study the homeostasis of a membrane proteome. Furthermore, E. coli is the most widely used host for producing (membrane) proteins and there is a constant and pressing need for better performing strains. In our studies, we combine advanced bacterial genetics, flow cytometry/cell sorting, genome sequencing, transcriptomics, proteomics, bioinformatics, cross-linking and lipid chemistry.

Last updated on 2017-01-06 at 13:46