Explore the vast range of titles available.

Nuclear pore complexes play central roles as gatekeepers of RNA and protein transport between the cytoplasm and nucleoplasm. However, their large size and dynamic nature have impeded a full structural and functional elucidation. Here we determined the structure of the entire 552-protein nuclear pore complex of the yeast Saccharomyces cerevisiae at sub-nanometre precision by satisfying a wide range of data relating to the molecular arrangement of its constituents. The nuclear pore complex incorporates sturdy diagonal columns and connector cables attached to these columns, imbuing the structure with strength and flexibility. These cables also tie together all other elements of the nuclear pore complex, including membrane-interacting regions, outer rings and RNA-processing platforms. Inwardly directed anchors create a high density of transport factor-docking Phe-Gly repeats in the central channel, organized into distinct functional units. This integrative structure enables us to rationalize the architecture, transport mechanism and evolutionary origins of the nuclear pore complex. The structure of the yeast nuclear pore complex, determined at sub-nanometre precision using an integrative approach that combines a wide range of data, reveals details of its architecture, transport mechanism and evolutionary origins. Structure of yeast nuclear pore complex Nuclear pore complexes (NPCs) are the gateways for the transport of RNA and proteins into and out of the nucleus. Although previous work has provided structural insights into parts of NPCs, getting a full picture of these complexes has proved difficult owing to their large size and dynamic nature. A multidisciplinary team of researchers now report the structure of the entire 552-protein NPC of the yeast at a sub-nanometre level using an integrative approach including mass spectrometry, cryo-electron tomography and chemical crosslinking. The structure provides a detailed view of the functional elements of the NPC and clarifies its architecture, mechanism of action and evolutionary origins.

This paper presents an efficient method for generating nanobodies with high affinity and high specificity. In addition, a collection of nanobodies specific for GFP or mCherry that resulted from this work is described. Nanobodies are single-domain antibodies derived from the variable regions of Camelidae atypical immunoglobulins. They show promise as high-affinity reagents for research, diagnostics and therapeutics owing to their high specificity, small size (∼15 kDa) and straightforward bacterial expression. However, identification of repertoires with sufficiently high affinity has proven time consuming and difficult, hampering nanobody implementation. Our approach generates large repertoires of readily expressible recombinant nanobodies with high affinities and specificities against a given antigen. We demonstrate the efficacy of this approach through the production of large repertoires of nanobodies against two antigens, GFP and mCherry, with K d values into the subnanomolar range. After mapping diverse epitopes on GFP, we were also able to design ultrahigh-affinity dimeric nanobodies with K d values as low as ∼30 pM. The approach presented here is well suited for the routine production of high-affinity capture reagents for various biomedical applications.

Nuclear Pore Complexes (NPCs) mediate the nucleocytoplasmic transport of macromolecules. Here we provide a structure of the yeast NPC in which the inner ring is resolved by cryo-EM at - helical resolution to show how flexible connectors tie together different structural and functional layers in the spoke. These connectors are targets for phosphorylation and regulated disassembly in cells with an open mitosis. Moreover, some nucleoporin pairs and karyopherins have similar interaction motifs, which suggests an evolutionary and mechanistic link between assembly and transport. We also provide evidence for three major NPC variants that foreshadow functional specializations at the nuclear periphery. Cryo-electron tomography extended these studies to provide a comprehensive model of the in situ NPC with a radially-expanded inner ring. Our model reveals novel features of the central transporter and nuclear basket, suggests a role for the lumenal ring in restricting dilation and highlights the structural plasticity required for transport by the NPC.

Background: Syndactyly, the congenital fusion of digits, compromises hand function and esthetics. Although surgical separation is the standard treatment, the optimal timing of the intervention remains controversial. Methods: We prospectively analyzed 20 pediatric patients (86 operated fingers) undergoing syndactyly repair, comparing early (≤24 months) versus delayed (>24 months) surgery. Outcome measures included range of motion (ROM) at the metacarpophalangeal (MP), proximal interphalangeal (PIP), and distal interphalangeal (DIP) joints; complications (synostosis, nail deformities, finger length disparity, webbing); and patient-reported outcomes assessed by the Disabilities of the Arm, Shoulder, and Hand (DASH) and overall esthetic satisfaction scores. Results: The median age at surgery was 31 months (IQR25/75: 24.75–36.5), with a median follow-up of 72 months (IQR25/75: 42.0–86.25). Notably, digits III (28.24%) and IV (29.41%) were predominantly affected. Delayed surgery resulted in significantly improved MP ROM (90.98° ± 8.44° vs. 73.13° ± 22.37°, p = 0.004) and DIP ROM (76.28° ± 22.24° vs. 67.19° ± 22.78°, p = 0.028), with a non-significant trend toward better PIP ROM (93.00° ± 25.18° vs. 77.37° ± 30.29°, p = 0.075). Furthermore, the incidence of synostosis was markedly reduced in the delayed surgery group (6.0% vs. 38.9%, p = 0.001). Despite superior joint function associated with delayed intervention, early surgery patients reported higher satisfaction with cosmetic results (3.00 vs. 2.80, p = 0.028), while the DASH scores remained comparably low between groups (0.00 vs. 0.24, p = 0.141). Finger length disparities and webbing were minimal. Conclusions: Our study challenges the conventional advocacy for early syndactyly repair, by demonstrating that delaying surgery beyond 24 months significantly enhances joint mobility and reduces the synostosis rate. However, the higher satisfaction observed as a result of early intervention suggests that surgical timing should be individualized for affected fingers, joints, and severities to balance the functional and cosmetic outcomes. Further studies are needed to define the optimal surgical timing and techniques for pediatric syndactyly.

Age-dependent changes in DNA methylation allow chronological and biological age inference, but the underlying mechanisms remain unclear. Using ultra-deep sequencing of >300 blood samples from healthy individuals, we show that age-dependent DNA methylation changes are regional and occur at multiple adjacent CpG sites, either stochastically or in a coordinated block-like manner. Deep learning analysis of single-molecule patterns in two genomic loci achieved accurate age prediction with a median error of 1.46-1.7 years on held-out human blood samples, dramatically improving current epigenetic clocks. Factors such as gender, BMI, smoking and other measures of biological aging do not affect chronological age inference. Longitudinal 10-year samples revealed that early deviations from epigenetic age are maintained throughout life and subsequent changes faithfully record time. Lastly, the model inferred chronological age from as few as 50 DNA molecules, suggesting that age is encoded by individual cells. Overall, DNA methylation changes in clustered CpG sites illuminate the principles of time measurement by cells and tissues, and facilitate medical and forensic applications.