Liquid-liquid phase separation of proteins underpins the formation of membraneless compartments in living cells. Elucidating the molecular driving forces underlying protein phase transitions is ...therefore a key objective for understanding biological function and malfunction. Here we show that cellular proteins, which form condensates at low salt concentrations, including FUS, TDP-43, Brd4, Sox2, and Annexin A11, can reenter a phase-separated regime at high salt concentrations. By bringing together experiments and simulations, we demonstrate that this reentrant phase transition in the high-salt regime is driven by hydrophobic and non-ionic interactions, and is mechanistically distinct from the low-salt regime, where condensates are additionally stabilized by electrostatic forces. Our work thus sheds light on the cooperation of hydrophobic and non-ionic interactions as general driving forces in the condensation process, with important implications for aberrant function, druggability, and material properties of biomolecular condensates.
We discovered that (histamine)(18-crown-6)
BF
is a high-temperature host-guest inclusion complex that presents decent piezoelectric properties (
= 5 pC/N), undergoes a phase transition at 406 K, and ...also possesses potential ferroelectricity. This work provides a new idea for constructing host-guest inclusion piezoelectrics.
Temperature controls plant growth and development, and climate change has already altered the phenology of wild plants and crops
. However, the mechanisms by which plants sense temperature are not ...well understood. The evening complex is a major signalling hub and a core component of the plant circadian clock
. The evening complex acts as a temperature-responsive transcriptional repressor, providing rhythmicity and temperature responsiveness to growth through unknown mechanisms
. The evening complex consists of EARLY FLOWERING 3 (ELF3)
, a large scaffold protein and key component of temperature sensing; ELF4, a small α-helical protein; and LUX ARRYTHMO (LUX), a DNA-binding protein required to recruit the evening complex to transcriptional targets. ELF3 contains a polyglutamine (polyQ) repeat
, embedded within a predicted prion domain (PrD). Here we find that the length of the polyQ repeat correlates with thermal responsiveness. We show that ELF3 proteins in plants from hotter climates, with no detectable PrD, are active at high temperatures, and lack thermal responsiveness. The temperature sensitivity of ELF3 is also modulated by the levels of ELF4, indicating that ELF4 can stabilize the function of ELF3. In both Arabidopsis and a heterologous system, ELF3 fused with green fluorescent protein forms speckles within minutes in response to higher temperatures, in a PrD-dependent manner. A purified fragment encompassing the ELF3 PrD reversibly forms liquid droplets in response to increasing temperatures in vitro, indicating that these properties reflect a direct biophysical response conferred by the PrD. The ability of temperature to rapidly shift ELF3 between active and inactive states via phase transition represents a previously unknown thermosensory mechanism.
A statistical model for the equation of state and the composition of supernova matter is presented. It consists of an ensemble of nuclei and interacting nucleons in nuclear statistical equilibrium. A ...relativistic mean field model is applied for the nucleons. The masses of the nuclei are taken from experimental data and from nuclear structure calculations. Excluded volume effects are implemented in a thermodynamic consistent way so that the transition to uniform nuclear matter can be described. Thus the model can be applied at all densities relevant for supernova simulations, i.e.
ρ
=
10
5
–
10
15
g
/
cm
3
, and it is possible to calculate a complete supernova equation of state table. The importance of the nuclear distributions for the composition is shown and the role of shell effects is investigated. We find a significant contribution of light clusters which is only poorly represented by
α-particles alone. The equation of state is systematically compared to two commonly used models for supernova matter which are based on the single nucleus approximation. In general only small differences are found. These are most pronounced around the (low-density) liquid–gas phase transition line where the distribution of light and intermediate clusters has an important effect.
Intracellular ribonucleoprotein (RNP) granules are membrane‐less droplet organelles that are thought to regulate posttranscriptional gene expression. While liquid–liquid phase separation may drive ...RNP granule assembly, the mechanisms underlying their supramolecular dynamics and internal organization remain poorly understood. Herein, we demonstrate that RNA, a primary component of RNP granules, can modulate the phase behavior of RNPs by controlling both droplet assembly and dissolution in vitro. Monotonically increasing the RNA concentration initially leads to droplet assembly by complex coacervation and subsequently triggers an RNP charge inversion, which promotes disassembly. This RNA‐mediated reentrant phase transition can drive the formation of dynamic droplet substructures (vacuoles) with tunable lifetimes. We propose that active cellular processes that can create an influx of RNA into RNP granules, such as transcription, can spatiotemporally control the organization and dynamics of such liquid‐like organelles.
Vacuolated ribonucleoprotein droplets: RNA controls the reentrant phase transition of ribonucleoproteins (RNPs) to assemble and dissolve RNP droplets. During dissolution, controlled RNA flux into the RNP droplets generates dynamic vacuolated substructures with tunable lifetimes.
Coexisting monoclinic M(1) (insulating) and rutile (metallic) domains were observed in free-standing vanadium dioxide nanobeams at room temperature. Similar domain structures have been attributed to ...interfacial strain, which was not present here. Annealing under reducing conditions indicated that a deficiency of oxygen stabilizes the rutile phase to temperatures as low as 103 K, which represents an unprecedented suppression of the phase transition by 238 K. In a complementary manner, oxygen-rich growth conditions stabilize the metastable monoclinic M(2) and triclinic T (or M(3)) phases. A pseudophase diagram with dimensions of temperature and stoichiometry is established that highlights the accessibility of new phases in the nanobeam geometry.
Infinite‐Layer Nickelates
In article number 2304146, Kui‐juan Jin and co‐workers report the novel photoinduced insulator‐metal and superconducting‐like phase transitions in the infinite‐layer NdNiO2 ...film, bringing forward a unique way to manipulate the electronic correlation with photons and trigger intriguing quantum phase transitions.
Oxidation‐Responsive Supramolecular Hydrogels
In article number 2312999, Hiroshi Katagiri, Masato Ikeda, and Yuki Shintani present new findings on oxidation‐responsive autonomous gel–sol–gel ...transitions of a supramolecular hydrogel, which is constructed via self‐assembly of a simple cysteine derivative. The formation of diastereomeric sulfoxides and their different self‐assembly modes play essential roles in the autonomous and plural, macroscopic phase transitions.
2D triangular β‐Cu2S nanosheets with large size and high quality are synthesized by a novel method of super‐cooling chemical‐vapor‐deposition. The phase transition of this 2D material from β‐Cu2S to ...γ‐Cu2S occurs at 258 K (−15 °C), and such transition temperature is 120 K lower than that of its bulk counterpart (about 378 K).
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