Thermodynamic profile of mutual subunit control in a heteromeric receptor [Biophysics and Computational Biology]

Cyclic nucleotide-gated (CNG) ion channels of olfactory neurons are tetrameric membrane receptors that are composed of two A2 subunits, one A4 subunit, and one B1b subunit. Each subunit carries a cyclic nucleotide-binding domain in the carboxyl terminus, and the channels are activated by the binding of cyclic nucleotides. The mechanism...

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Mechanism of the formation of proton transfer pathways in photosynthetic reaction centers [Biochemistry]

In photosynthetic reaction centers from purple bacteria (PbRCs) from Rhodobacter sphaeroides, the secondary quinone QB accepts two electrons and two protons via electron-coupled proton transfer (PT). Here, we identify PT pathways that proceed toward the QB binding site, using a quantum mechanical/molecular mechanical approach. As the first electron...

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EZH2 inhibits NK cell-mediated antitumor immunity by suppressing CXCL10 expression in an HDAC10-dependent manner [Medical Sciences]

Enhancer of zeste homolog 2 (EZH2) is a histone H3 lysine 27 methyltransferase that has been shown to function as an oncogene in some cancers. Previous reports have largely focused on the ability of EZH2 to regulate cell-intrinsic tumor regulatory pathways as its mechanism-of-oncogenic action. However, the role that EZH2-mediated...

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Three mutations repurpose a plant karrikin receptor to a strigolactone receptor [Plant Biology]

Uncovering the basis of small-molecule hormone receptors’ evolution is paramount to a complete understanding of how protein structure drives function. In plants, hormone receptors for strigolactones are well suited to evolutionary inquiries because closely related homologs have different ligand preferences. More importantly, because of facile plant...

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Experimental evidence for glass polymorphism in vitrified water droplets [Applied Physical Sciences]

The nature of amorphous ices has been debated for more than 35 years. In essence, the question is whether they are related to ice polymorphs or to liquids. The fact that amorphous ices are traditionally prepared from crystalline ice via pressure-induced amorphization has made a clear distinction tricky. In this...

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Profile of Patrick Cramer [Profiles]

Patrick Cramer’s interest in the scientific method may have been sparked by a childhood gift. While growing up, his parents gave him a kit to try little experiments at home that inspired him to become a scientist. Patrick Cramer. Image credit: Patrick Cramer. Cramer studied chemistry, first at the University...

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Structures and implications of TBP-nucleosome complexes [Biophysics and Computational Biology]

The TATA box-binding protein (TBP) is highly conserved throughout eukaryotes and plays a central role in the assembly of the transcription preinitiation complex (PIC) at gene promoters. TBP binds and bends DNA, and directs adjacent binding of the transcription factors TFIIA and TFIIB for PIC assembly. Here, we show that...

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Repeating caldera collapse events constrain fault friction at the kilometer scale [Earth, Atmospheric, and Planetary Sciences]

Fault friction is central to understanding earthquakes, yet laboratory rock mechanics experiments are restricted to, at most, meter scale. Questions thus remain as to the applicability of measured frictional properties to faulting in situ. In particular, the slip-weakening distance dc strongly influences precursory slip during earthquake nucleation,...

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Optical conductivity and superconductivity in highly overdoped La2-xCaxCuO4 thin films [Physics]

We have used atomic layer-by-layer oxide molecular beam epitaxy to grow epitaxial thin films of La2−xCaxCuO4 with x up to 0.5, greatly exceeding the solubility limit of Ca in bulk systems (x∼0.12). A comparison of the optical conductivity measured by spectroscopic ellipsometry to prior predictions from dynamical mean-field theory demonstrates...

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Probabilistic discrimination of relative stimulus features in mice [Neuroscience]

During perceptual decision-making, the brain encodes the upcoming decision and the stimulus information in a mixed representation. Paradigms suitable for studying decision computations in isolation rely on stimulus comparisons, with choices depending on relative rather than absolute properties of the stimuli. The adoption of tasks requiring relative...

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