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Osmoadaptation and salt-in strategy

11 articles

Acidic proteome of halophilic archaea

The acidic proteome of halophilic archaea is the proteome-wide shift toward aspartate- and glutamate-rich, hydrophobic-poor protein surfaces that lets proteins fold only in saturated salt.

Betaine transporter

Betaine transporter: membrane proteins (BCCT family, ABC types such as OpuA/OpuD/BetP/Ota, and mammalian BGT1) that import glycine betaine as an osmoprotectant in bacteria, archaea, and mammals.

Compatible-solute biosynthesis in halophiles

Compatible-solute biosynthesis is how halophilic and halotolerant microbes make organic osmolytes like glycine betaine and ectoine to balance osmotic pressure instead of using the salt-in strategy.

Compatible-solute uptake and transport in halophilic archaea

Compatible-solute uptake and transport in halophilic archaea is the membrane transport by which salt-loving archaea import protective molecules like glycine betaine and ectoine, mostly through sodium-coupled symporters.

Ectoine

Ectoine, a zwitterionic tetrahydropyrimidine compatible solute discovered in 1985 in Ectothiorhodospira halochloris, protects microbes against osmotic, heat, cold, and desiccation stress; produced industrially and used in atopic dermatitis creams and cryopreservation.

Halophile

Halophile: salt-loving microorganism requiring or tolerating high NaCl, found across Archaea, Bacteria, and Eukarya; classified slight, moderate, or extreme; uses salt-in or salt-out osmoadaptation; industrially valued for halozymes and bioplastics.

Mechanosensitive channels

Mechanosensitive channels are membrane proteins that convert mechanical force into ion flow. Key families: bacterial MscL/MscS osmotic safety valves and mammalian Piezo1/2 touch channels, recognized by the 2021 Nobel Prize.

Osmotic physiology in hypersaline niches

Osmotic physiology in hypersaline niches is the study of how microorganisms balance water across cell membranes in brines too salty for most life, spanning the salt-in and salt-out strategies.

Salt-dependent enzyme folding in halophilic archaea

Salt-dependent enzyme folding is the requirement of enzymes from extremely halophilic archaea for molar salt, usually KCl, to fold and stay folded; without it, many proteins unfold.

Salt-in strategy

The salt-in strategy is an osmoadaptation used by haloarchaea, and convergently by the bacterium Salinibacter ruber, which accumulate molar intracellular KCl instead of organic solutes.

Small-conductance mechanosensitive channel

MscS, the small-conductance mechanosensitive channel of E. coli, is a heptameric ~1 nS tension-gated bacterial emergency release valve protecting cells from hypoosmotic shock, founding member of the MscS-like superfamily.