Biomolecular Condensates under Extreme Martian Salt Conditions

• Main Authors: Zamira Fetahaj (10358155), Lena Ostermeier (10358158), Hasan Cinar (6623576), Rosario Oliva (5843357), Roland Winter (439256)
• Format: Other Non-Article Part of Journal/Newspaper
• Language: unknown
• Published: 2021
• Subjects: Biochemistry; Evolutionary Biology; Virology; Environmental Sciences not elsewhere classified; Astronomical and Space Sciences not elsewhere classified; Biological Sciences not elsewhere classified; Chemical Sciences not elsewhere classified; ion correlation effects; biomolecular; sequence; Mars; Extreme Martian Salt Conditions Bio.; formation; interaction; phase separation; protein; LLPS; saline water pools; Antarc*; Antarctica
• Online Access: https://doi.org/10.1021/jacs.1c01832.s001

Biomolecular condensates formed by liquid–liquid phase separation (LLPS) are considered one of the early compartmentalization strategies of cells, which still prevail today forming nonmembranous compartments in biological cells. Studies of the effect of high pressures, such as those encountered in the subsurface salt lakes of Mars or in the depths of the subseafloor on Earth, on biomolecular LLPS will contribute to questions of protocell formation under prebiotic conditions. We investigated the effects of extreme environmental conditions, focusing on highly aggressive Martian salts (perchlorate and sulfate) and high pressure, on the formation of biomolecular condensates of proteins. Our data show that the driving force for phase separation of proteins is not only sensitively dictated by their amino acid sequence but also strongly influenced by the type of salt and its concentration. At high salinity, as encountered in Martian soil and similar harsh environments on Earth, attractive short-range interactions, ion correlation effects, hydrophobic, and π-driven interactions can sustain LLPS for suitable polypeptide sequences. Our results also show that salts across the Hofmeister series have a differential effect on shifting the boundary of immiscibility that determines phase separation. In addition, we show that confinement mimicking cracks in sediments and subsurface saline water pools in the Antarctica or on Mars can dramatically stabilize liquid phase droplets, leading to an increase in the temperature and pressure stability of the droplet phase.