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Summary: Ribosome biogenesis is a highly dynamic and orchestrated process facilitated by hundreds of ribosomal biogenesis factors and small nucleolar RNAs. While many of the advances are derived from studies in yeast, ribosome biogenesis remains largely unknown in plants despite its importance to plant growth and development.Through characterizing the maize (Zea mays) defective kernel and embryo‐lethal mutant dek58, we show that DEK58 encodes an Rrp15p domain‐containing protein with 15.3% identity to yeast Rrp15. Over‐expression of DEK58 rescues the mutant phenotype.DEK58 is localized in the nucleolus. Ribosome profiling and RNA gel blot analyses show that the absence of DEK58 reduces ribosome assembly and impedes pre‐rRNA processing, accompanied by the accumulation of nearly all the pre‐rRNA processing intermediates and the production of an aberrant processing product P‐25S*. DEK58 interacts with ZmSSF1, a maize homolog of the yeast Ssf1 in the 60S processome. DEK58 and ZmSSF1 interact with ZmCK2α, a putative component of the yeast UTP‐C complex involved in the small ribosomal subunit processome.These results demonstrate that DEK58 is essential to seed development in maize. It functions in the early stage of pre‐rRNA processing in ribosome biogenesis, possibly through interacting with ZmSSF1 and ZmCK2α in maize. [ABSTRACT FROM AUTHOR]

The Tiegelongnan deposit is a giant deposit (>10 million tons Cu resources with an average grade of 0.53%) located in the west of the Bangong Co‐Nujiang metallogenic Belt, where typical porphyry and epithermal types of alteration and mineralization are developed. A compilation of geological features and mineralogical studies revealed that the Tiegelongnan deposit developed two stages of hydrothermal alteration. The early stage was related to porphyry emplacement, developing potassic, phyllic and propylitic alterations, telescoped by the late advanced argillic alteration in the shallow levels. Correspondingly, two stages of mineralization occurred, the early porphyry‐type mineralization being overlapped by the late high‐sulfidation epithermal mineralization. Due to differences in pH, log fO2, K+ activity and temperature of ore‐forming fluids, distinct sulfide minerals of low to extremely high sulfidation states, such as chalcopyrite, tennantite, enargite and covellite, precipitated throughout the entire hydrothermal process. The Tiegelongnan deposit is a complex porphyry metallogenetic system of 'multiple structures'. The Early Cretaceous andesitic volcanic rocks of the Meiriqiecuo Formation exposed on the surface act as a cap for the ore body, beneath which an oxidizing‐leaching zone lies. Under the cap and the oxidizing‐leaching zone, a porphyry ore body is remoulded by high‐grade high‐sulfidation epithermal hydrothermal mineralization, which gradually transitions to continuous porphyry‐type mineralization at depth. [ABSTRACT FROM AUTHOR]

The lack of M–Fe–S (M = Mo or W) clusters incorporating a second period (2p) atom in the core has resulted in limited investigations and poor understanding of the physical and chemical properties of the M–Fe–S clusters closely related to the FeMo cofactor. In this work, systematic studies have been carried out to explore the chemical reactivities at the terminal ligand sites and the redox properties of a series of clusters comprising a [WFe3S3N] cubane core, based on the previously developed cluster [(Tp*)WFe3S3(μ3-NSiMe3)Cl3]1−. Substitutions of the terminal chlorides with ethanethiolate, methanethiolate, thiophenolate, p-thiocresolate and azide occurred smoothly, while the replacement of the chlorides with carbene ligands required the reduction of the precursor into [(Tp*)WFe3S3(μ3-NSiMe3)Cl3]2− first. The reduced cluster core could also be supported by thiophenolates as terminal ligands, but not thiolates or azides. It is remarkable that the thiophenolate ligated reduced cluster can be synthesized from the precursor [(Tp*)WFe3S3(μ3-NSiMe3)Cl3]1−via different synthetic routes, either reduction followed by substitution or substitution followed by reduction, either in situ or stepwise. This work indicates that terminal ligands contribute significantly to determine the chemical and physical properties of the clusters, even though they might affect the cluster core to a limited extent from a structural point of view, which raises the possibility of delicate control in regulating the physical/chemical properties of M–Fe–S clusters with a heteroleptic core incorporating 2p atom(s). [ABSTRACT FROM AUTHOR]

The erroneous differentiation of tendon‐derived stem cells (TDSCs) into adipocytes, chondrocytes, and osteoblasts is believed to play an important role in the development of tendinopathy. However, the regulatory mechanisms of TDSC differentiation remain unclear. The aim of this study is to investigate the contribution and mechanism of the tendon microstructural disruption to the differentiation of TDSCs. Bovine Achilles tendons were sliced. The tendon slices were stretched with different tensile strains to mimic the tendon structure alteration at various scales. The TDSCs were cultured on the tendon slices. The differentiation of TDSCs and endoplasmic reticulum (ER) stress in the TDSCs were investigated with quantitative reverse transcription polymerase chain reaction, immunostaining and western blot. The effect of ER stress inhibition on chondrogenic differentiation of the TDSCs was further investigated. The structural alteration did not affect the viability of TDSCs. However, the structural alteration of tendon slices with 6.4% strain promoted TDSCs to express the chondrogenic genes. ER stress‐related markers, ATF‐4 and PERK, were also upregulated. With the inhibition of ER stress, the expression of ATF‐4 and the chondrogenic gene SOX9 of TDSCs were inhibited. The study indicated that tendon microdamage could induce the chondrogenic differentiation of TDSCs through triggering ER stress to activate ATF‐4 and SOX9 subsequently. [ABSTRACT FROM AUTHOR]

C10H9Cl2NO4, orthorhombic, Pbca, a = 11.151(2) Å, b = 7.0923(14) Å, c = 29.243(6) Å, V = 2312.7(8) Å3, Z = 8, Rgt(F) = 0.0459, wRref(F2) = 0.1223, T = 293 K.