The specific activation of TRPC4 by Gi protein subtype

The classical type of transient receptor potential channel (TRPC) is a molecular candidate for Ca²⁺-permeable cation channels in mammalian cells. Especially, TRPC4 has the similar properties to Ca²⁺-permeable nonselective cation channels (NSCCs) activated by muscarinic stimulation in visceral smooth muscles. In visceral smooth muscles, NSCCs activated by muscarinic stimulation were blocked by anti-Gαi/o antibodies. However, there is still no report which Gα proteins are involved in the activation process of TRPC4. Among Gα proteins, only Gαi protein can activate TRPC4 channel. The activation effect of Gαi was specific for TRPC4 because Gαi has no activation effect on TRPC5, TRPC6 and TRPV6. Coexpression with muscarinic receptor M2 induced TRPC4 current activation by muscarinic stimulation with carbachol, which was inhibited by pertussis toxin. These results suggest that Gαi is involved specifically in the activation of TRPC4.     

Radical formation of 5,10,15,20-tetra(4-sulfophenyl) porphinatopalladium(II)(4−) in the lowest excited triplet states

Excited 5,10,15,20-tetra(4-sulfopheny)porphinatopalladium(II) (PdTPPS⁴⁻) was studied by phosphorescence lifetime, phosphorescence quenching, delayed fluorescence, and transient absorption measurements in terms of the dimerization reaction. Lifetimes of monomer and dimer was determined as τ=360 and 270 μs, respectively. The self-association rates of PdTPPS⁴⁻ in the excited and ground states are the same. Transient absorption unveiled the radical formation resulted from the charge separation after photo excitation.     

Temperature dependence of biphasic forward electron transfer from the phylloquinone(s) A1 in photosystem I: only the slower phase is activated

The temperature dependence of the biphasic electron transfer (ET) from the secondary acceptor A1 (phylloquinone) to iron-sulfur cluster F_X was investigated by flash absorption spectroscopy in photosystem I (PS I) isolated from Synechocystis sp. PCC 6803. While the slower phase (τ=340 ns at 295 K) slowed upon cooling according to an activation energy of 110 meV, the time constant of the faster phase (τ=11 ns at 295 K) was virtually independent of temperature. Following a suggestion in the literature that the two phases arise from bidirectional ET involving two symmetrically arranged phylloquinones, Q_K-A and Q_K-B, it is concluded that energetic parameters (most likely the driving forces) rather than the electronic couplings are different for ET from Q_K-A to F_X and from Q_K-B to F_X. Two alternative schemes of ET in PS I are presented and discussed.     

Amino acid substitution of arginine 80 in 17β-hydroxysteroid dehydrogenase type 3 and its effect on NADPH cofactor binding and oxidation/reduction kinetics

17β-Hydroxysteroid dehydrogenase type 3 (17β-HSD-3) is a member of the short-chain dehydrogenase/reductase (SDR) family and is essential for the reductive conversion of inactive C₁₉-steroid, androstenedione, to the biologically active androgen, testosterone, which plays a central role in the development of the male phenotype. Mutations that inactivate this enzyme give rise to a rare form of male pseudohermaphroditism, referred to as 17β-HSD-3 deficiency. One such mutation is the replacement of arginine at position 80 with glutamine, compromising enzyme activity by increasing the cofactor binding constant 60-fold. In the absence of a 17β-HSD-3 crystal structure, we have grafted its amino acid sequence for the NADPH binding site on the X-ray crystal structures of glutathione reductase (Protein Data Bank code 1gra) and 17β-HSD type 1 (Protein Data Bank codes 1fdv and 1fdu) where we find the trunk of the arginine 80 side chain forms part of the hydrophobic pocket for the purine ring of adenosine while its guanidinium moiety interacts with the 2′-phosphate to both stabilize cofactor binding and neutralize its intrinsic negative charge through two hydrogen bonds. To qualitatively assess the role arginine 80 plays in both selecting and stabilizing NADPH binding, it was replaced with each amino acid and the mutant enzymes subjected to enzymatic analysis. There are only seven enzymes exhibiting any measurable enzymatic activity with arginine～lysine>leucine>glutamine>methionine>tyrosine>isoleucine. With an aspartic acid at position 58 in 17β-HSD-3 occupying the equivalent space in the cofactor binding pocket as arginine 224 in glutathione reductase or serine 12 in 17β-HSD-1, there was an expectation that some of the mutants might use NADH as a cofactor. In no case was NADH found to substitute for NADPH.     

Computation,wiring, and plasticity in synaptic clusters

Synaptic clusters on dendrites are extraordinarily compact computational building blocks. They contribute to key local computations through biophysical and biochemical signaling that utilizes convergence in space and time as an organizing principle. However, these computations can only arise in very special contexts. Dendritic cluster computations, their highly organized input connectivity, and the mechanisms for their formation are closely linked, yet these have not been analyzed as parts of a single process. Here, we examine these linkages. The sheer density of axonal and dendritic arborizations means that there are far more potential connections (close enough for a spine to reach an axon) than actual ones. We see how dendritic clusters draw upon electrical, chemical, and mechano–chemical signaling to implement the rules for formation of connections and subsequent computations. Crucially, the same mechanisms that underlie their functions also underlie their formation.     

Hyperosmotic stress alters the RNA polymerase II interactome and induces readthrough transcription despite widespread transcriptional repression

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Novel benzodiazepines derivatives as analgesic modulating for Transient receptor potential vanilloid 1

A new series of derivatives of 3-(7-chloro-5-(2-fluorophenyl)-2-oxo-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)propanoic acid were designed and synthesized as analgesic modulating for Transient receptor potential vanilloid 1. They were investigated for TRPV1 antagonistic activity in vitro, analgesic activity and sedative activity in vivo and aqueous solubility. Preliminary studies identified 3-(7-chloro-5-(2-fluorophenyl)-2-oxo-2,3-dihydro-1H-benzo[e][1,4]diazepin-3-yl)-N,N-dimethylpropanamide(Compound 11), as a potent analgesic modulating for TRPV1 with potent activity and good aqueous solubility.     

Diffraction‐Grated Perovskite Induced Highly Efficient Solar Cells through Nanophotonic Light Trapping

Achieving light harvesting is crucial for the efficiency of the solar cell. Constructing optical structures often can benefit from micro‐nanophotonic imprinting. Here, a simple and facile strategy is developed to introduce a large area grating structure into the perovskite‐active layer of a solar cell by utilizing commercial optical discs (CD‐R and DVD‐R) and achieve high photovoltaic performance. The constructed diffraction grating on the perovskite active layer realizes nanophotonic light trapping by diffraction and effectively suppresses carrier recombination. Compared to the pristine perovskite solar cells (PSCs), the diffraction‐grating perovskite devices with DVD obtain higher power conversion efficiency and photocurrent density, which are improved from 16.71% and 21.67 mA cm^?2 to 19.71% and 23.11 mA cm^?2. Moreover, the stability of the PSCs with diffraction‐grating‐structured perovskite active layer is greatly enhanced. The method can boost photonics merge into the remarkable perovskite materials for various applications.     

沙冬青子叶原生质体瞬时表达体系的建立及其AmDREB1蛋白的亚细胞定位

以沙冬青(Ammopiptanthus mongolicus(Maxim.ex Kom.)Cheng f.)幼苗的子叶为材料,对其原生质体的分离、纯化和瞬时表达体系进行了研究。结果表明,子叶原生质体分离的最佳酶解液组成为CPW溶液+3.0%纤维素酶R-10+0.5%离析酶R-10+0.3%半纤维素酶+9.0%甘露醇(p H5.8);最佳酶解条件为室温、避光、40 r/min轻摇14 h。采用W5溶液作为漂洗液将酶解物稀释后进行过滤,将过滤液在4℃、700 r/min条件下离心5 min,所得纯化原生质体的产量约为2.50×106cells/g,活力达到90%;以纯化的原生质体作为受体,利用聚乙二醇(PEG)介导法成功将植物瞬时表达载体p BI-GFP导入其中,转化效率达到50.8%。利用本研究建立的原生质体瞬时表达体系,检测到沙冬青脱水应答转录因子Am DREB1定位于细胞核内。