The inner membrane associated protein of 30 kDa (IM30)
The inner membrane associated protein of 30 kDa (IM30), also known as the vesicle-inducing protein in plastids 1 (Vipp1), is crucially involved in the formation, maintenance and dynamics of thylakoid membranes in cyanobacteria and chloroplasts. In a recent bioinformatic analysis, IM30 was identified as a member of the endosomal sorting complex required for transport (ESCRT-III) superfamily, a protein family previously liked exclusively with eukaryotes. Like other members of the ESCRT-III superfamily, IM30 forms large oligomeric structures, binds to and remodels membranes. In vivo, fluorescently labeled IM30 accumulates at specific sites and forms currently ill-defined punctae structures. It is assumed that these are condensates that assist in repairing membrane damage. How exactly these condensates form and how they help to repair the membrane is one of the many questions that are still unanswered and are currently being investigated in our lab.
Read more:
- Siebenaller C. and Schneider D. (2023) Cyanobacterial membrane dynamics in the light of eukaryotic principles, Biosci Rep 43 (2), BSR20221269.
- Quarta N., Bhandari T.R., Girard M., Hellmann N. and Schneider D. (2024) Monomer unfolding of a bacterial ESCRT-III superfamily member is coupled to oligomer disassembly, Prot. Sci.
Dynamin like proteins (DLPs)
DLPs are mechano-chemical GTPases, which are involved in remodeling processes at various eukaryotic cell membranes. The classical dynamin protein is e.g. involved in vesicle formation at the plasma membrane. However, DLPs are also found organelles of prokaryotic origin (mitochondria and chloroplasts) as well as in bacteria. Due to their described membrane remodeling activity, DLPs are likely involved in thylakoid membrane biogenesis and dynamics in chloroplasts and cyanobacateria. Currently, we investigate the structure and activity of a DLP of the cyanobacterium Synechocystis sp. PCC6803. Besides in vivo analyses of mutant strains, we mainly evaluate the activity of the isolated protein in vitro and its impact on membrane structure and dynamics.
Read more:
- Gewehr L., Junglas B., Jilly R., Franz J., Zhu W. E., Weidner T., Bonn M., Sachse C. and Schneider D. (2023) SynDLP is a dynamin-like protein of Synechocystis sp. PCC 6803 with eukaryotic features, Nature Comm 14, 2156.
- Junglas B., Gewehr L., Mernberger L., Schönnenbeck P., Jilly R., Hellmann N., Schneider D., Sachse C. (2024) Structural basis for GTPase activity and conformational changes of the bacterial dynamin-like protein SynDLP, Cell Rep., 43 (9):114657