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In animal cells, replication-dependent histone pre-mRNAs are cleaved at the 3' end by U7 snRNP consisting of two core components: a ∼60-nucleotide U7 snRNA and a ring of seven proteins, with Lsm10 and Lsm11 replacing the spliceosomal SmD1 and SmD2. Lsm11 interacts with FLASH and together they recruit the endonuclease CPSF73 and other polyadenylation factors, forming catalytically active holo U7 snRNP. Here, we assembled core U7 snRNP bound to FLASH from recombinant components and analyzed its appearance by electron microscopy and ability to support histone pre-mRNA processing in the presence of polyadenylation factors from nuclear extracts. We demonstrate that semi-recombinant holo U7 snRNP reconstituted in this manner has the same composition and functional properties as endogenous U7 snRNP, and accurately cleaves histone pre-mRNAs in a reconstituted in vitro processing reaction. We also demonstrate that the U7-specific Sm ring assembles efficiently in vitro on a spliceosomal Sm site but the engineered U7 snRNP is functionally impaired. This approach offers a unique opportunity to study the importance of various regions in the Sm proteins and U7 snRNA in 3' end processing of histone pre-mRNAs.

ClC-1 protein channels facilitate rapid passage of chloride ions across cellular membranes, thereby orchestrating skeletal muscle excitability. Malfunction of ClC-1 is associated with myotonia congenita, a disease impairing muscle relaxation. Here, we present the cryo-electron microscopy (cryo-EM) structure of human ClC-1, uncovering an architecture reminiscent of that of bovine ClC-K and CLC transporters. The chloride conducting pathway exhibits distinct features, including a central glutamate residue ("fast gate") known to confer voltage-dependence (a mechanistic feature not present in ClC-K), linked to a somewhat rearranged central tyrosine and a narrower aperture of the pore toward the extracellular vestibule. These characteristics agree with the lower chloride flux of ClC-1 compared with ClC-K and enable us to propose a model for chloride passage in voltage-dependent CLC channels. Comparison of structures derived from protein studied in different experimental conditions supports the notion that pH and adenine nucleotides regulate ClC-1 through interactions between the so-called cystathionine-β-synthase (CBS) domains and the intracellular vestibule ("slow gating"). The structure also provides a framework for analysis of mutations causing myotonia congenita and reveals a striking correlation between mutated residues and the phenotypic effect on voltage gating, opening avenues for rational design of therapies against ClC-1-related diseases.

SUMMARY Vascular plant one‐zinc finger (VOZ) transcription factors (TFs) play crucial roles in plant immunity. Nevertheless, how VOZs modulate defense signaling in response to elicitor‐induced resistance is not fully understood. Here, the defense elicitor β‐aminobutyric acid (BABA) resulted in the visible suppression of Rhizopus rot disease of peach fruit caused by Rhizopus stolonifer. Defense priming by BABA was notably associated with increased levels of salicylic acid (SA) and SA‐dependent gene expression. Data‐independent acquisition proteomic analysis revealed that two VOZ proteins (PpVOZ1 and PpVOZ2) were substantially upregulated in BABA‐induced resistance (BABA‐IR). Furthermore, the interaction of PpVOZ1 and PpVOZ2 and their potential target of the TEOSINTE‐BRANCHED1/CYCLOIDEA/PCF (TCP)‐family protein PpTCP2 screened from protein–protein interaction networks was confirmed by yeast two‐hybrid (Y2H), luciferase complementation imaging and glutathione S‐transferase pull‐down assays. Furthermore, subcellular localization, yeast one‐hybrid, electrophoretic mobility shift assay and dual‐luciferase reporter assays demonstrated that nuclear localization of both PpVOZ1 and PpVOZ2 was critical for their contribution to BABA‐IR, as these proteins potentiated the PpTCP2‐mediated transcriptional activation of isochorismate synthase genes (ICS1/2). The overexpression of both PpVOZ1 and PpVOZ2 could activate the transcription of SA‐dependent genes and provide disease resistance in transgenic Arabidopsis. In contrast, the ppvoz1cas9 and ppvoz2cas9 loss‐of‐function mutations and the voz1cas9 voz2cas9 double mutation attenuated BABA‐IR against R. stolonifer. Therefore, the three identified positive TFs, PpVOZ1, PpVOZ2, and PpTCP2, synergistically contribute to the BABA‐activated priming of systemic acquired resistance in postharvest peach fruit by a VOZ‐TCP‐ICS regulatory module. [ABSTRACT FROM AUTHOR]

Dam foundations are prone to leakage damage after being exposed to long-term water action, which seriously affects the operation safety of the dam. At present, concrete cut-off walls serve an important means of anti-seepage for dam foundations. However, due to construction challenges, the cut-off wall needs to be poured segment-by-segment during the construction process, and the joints between adjacent segments become weak parts for seepage prevention. Therefore, it is crucial to clarify the stress state of segmented discontinuous concrete cut-off walls. Based on the Lee-Fenves framework and the tension–compression constitutive relationship of fracture energy, a plastic damage calculation method was established in this paper to characterize the mechanical behavior of discontinuous cut-off walls. The method was then used to analyze the mechanical performance of discontinuous walls with segment joints containing slurry cake. The research results showed that compared to the continuous cut-off wall, the vertical settlement in the middle part of the discontinuous cut-off wall increased by 5.8%, and the displacement along the river flow direction decreased by 35.3%. As the wall segment width decreased, the joint opening and the degree of tensile damage were reduced accordingly, while the compressive damage in the middle and lower parts of the wall was intensified. As the wall depth decreased, the constraints and load on the bottom of the wall showed obvious changes, leading to a reduced stress and damage level of the wall. The findings provide reference for the design and safety control of cut-off walls. [ABSTRACT FROM AUTHOR]

To accurately represent the proportional stress–strain behavior observed in granular materials, we extend the hypoplastic model originally proposed by Gudehus and Bauer. This extension incorporates two new tensorial terms. By introducing these terms and their associated coefficients, we establish an implicit relationship for oedometric proportional compression. Our numerical simulations, based on element tests, demonstrate that this extended model effectively describes the isotropic and oedometric proportional stress–strain behavior of granular materials. Furthermore, we outline the process for determining the constitutive parameters and discuss the corresponding calibration methods within this study. [ABSTRACT FROM AUTHOR]