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Biology subjects

Hasani, M.

Publications and source records attributed to Hasani, M..

2 recordsLinked to original sources

Controlled Protein-Membrane Interactions Regulate Self-Organization of Min Protein Patterns

Self-organizing protein patterns play an essential role in life, governing important cellular processes, such as polarization and division. While the field of protein self-organization has reached a point where basic pattern-forming mechanisms can be reconstituted in vitro using purified proteins, understanding how cells can dynamically switch and modulate these patterns, especially when transiently needed, remains an interesting frontier. Here, we demonstrate the efficient regulation of self-organizing protein patterns through modulation of simple biophysical membrane parameters. Our investigation focusses on the impact of membrane affinity changes on Min protein patterns at lipid membranes composed of E. coli lipids or minimal lipid composition and we present three major results. First, we observed the emergence of a diverse array of pattern phenotypes, ranging from waves to snowflake-like structures. Second, we establish the dependency of these patterns on the density of protein-membrane linkers. Finally, we demonstrate the fine-tuning of snow-flake-like patterns by regulating membrane charge through lipid composition. Our results demonstrate the significant influence of membrane linkage as a straightforward biophysical parameter governing protein pattern formation. Our research points towards a simple yet intriguing mechanism by which cells can adeptly tune and switch protein patterns on the mesoscale.

biophysics↗

Resin acids play key roles in shaping microbial communities during degradation of spruce bark

The bark is the outermost defense of trees against microbial attack, largely thanks to toxicity and prevalence of extractive compounds. Nevertheless, bark decomposes in nature, though by which species and mechanisms remains unknown. Here, we have followed the development of microbial enrichments growing on spruce bark over six months, by monitoring both chemical changes in the material and performing community and metagenomic analyses. Carbohydrate metabolism was unexpectedly limited, and instead a key activity was metabolism of extractives. Resin acid degradation was principally linked to community diversification with specific bacteria revealed to dominate the process. Metagenome-guided isolation facilitated the recovery of the dominant enrichment strain in pure culture, which represents a new species (Pseudomonas abieticivorans sp. nov.), that can grow on resin acids as a sole carbon source. Our results illuminate key stages in degradation of an abundant renewable resource, and how defensive extractive compounds have major roles in shaping microbiomes.

microbiology↗