A5037898159- Nuclear Structure and Function
- RNA Research and Splicing
- Genomics and Chromatin Dynamics
- Advanced Electron Microscopy Techniques and Applications
- Cellular transport and secretion
- Biotin and Related Studies
- Microtubule and mitosis dynamics
- Electron and X-Ray Spectroscopy Techniques
- Endoplasmic Reticulum Stress and Disease
- RNA regulation and disease
- RNA and protein synthesis mechanisms
- Plant Reproductive Biology
- Force Microscopy Techniques and Applications
- Bone and Dental Protein Studies
- Skin and Cellular Biology Research
- Photosynthetic Processes and Mechanisms
- RNA Interference and Gene Delivery
- Connexins and lens biology
- Virus-based gene therapy research
- Mitochondrial Function and Pathology
- Fungal and yeast genetics research
- Genetics, Aging, and Longevity in Model Organisms
- Viral Infections and Vectors
- Graphite, nuclear technology, radiation studies
- interferon and immune responses
Durham University
2015-2025
Université Paris Cité
2006
Cancer Research UK Manchester Institute
1992-2002
The Christie NHS Foundation Trust
1993-2001
National Health Service
1992-2000
The Christie Hospital
1999-2000
University of Dundee
1999
Johns Hopkins University
1991-1997
Johns Hopkins Medicine
1997
Institute of Cytology and Genetics
1996
During apoptosis, an important pathway leading to caspase activation involves the release of cytochrome c from intermembrane space mitochondria. Using a cell-free system based on Xenopus egg extracts, we examined changes in outer mitochondrial membrane accompanying efflux. The pro-apoptotic proteins, Bid and Bax, as well factors present cytosol, each induced when incubated with isolated These caused permeabilization that allowed corelease multiple proteins: c, adenylate kinase sulfite...
The nuclear envelope (NE) of amphibian oocytes can be readily isolated in relatively structurally intact and pure form has been used extensively for structural studies. Using high resolution scanning electron microscopy (HRSEM), both surfaces the NE visualized detail. Here, we demonstrate use HRSEM to obtain information structure, confirming previous data providing some new information. NEs, manually from Triturus cristatus oocytes, have mounted on conductive silicon chips, fixed, critical...
The nuclear pore complex (NPC) mediates bidirectional macromolecular traffic between the nucleus and cytoplasm in eukaryotic cells. Eight filaments project from NPC into are proposed to function import. We investigated localization of two nucleoporins on cytoplasmic face NPC, CAN/Nup214 RanBP2/Nup358. Consistent with previous data, RanBP2 was localized at filaments. In contrast, CAN near coaxial ring. Unexpectedly, extensive blocking gold-conjugated antibodies failed inhibit Therefore,...
Lamins are intermediate filament proteins and the major component of nuclear lamina. Current views lamina based on remarkably regular arrangement lamin LIII in amphibian oocyte nuclei. We have re-examined propose a new interpretation its organization. Rather than consisting two perpendicular arrays parallel filaments, we suggest that consists filaments interconnected register to give impression second set filaments. also used system investigate organization somatic lamins. Currently, it is...
The nuclear envelope (NE) is a fundamental structure of eukaryotic cells with dual role: it separates two distinct compartments, and enables communication between them via pore complexes (NPCs). Little known about NPCs NE structural organization in plants. We investigated the from both sides tobacco BY-2 cells. detected differences dividing quiescent nuclei. Importantly, we also traced organizational pattern NPCs, observed non-random NPC distribution over surface. Lastly, an organized...
ABSTRACT We used field emission in-lens scanning electron microscopy to examine newly-assembled, growing nuclear envelopes in Xenopus egg extracts. Scattered among pore complexes were rare ‘dimples’ (outer membrane depressions, 5-35 nm diameter), more abundant holes (pores) with a variety of edge geometries (35-45 diameter; 3.3% structures), pores containing one eight triangular ‘star-ring’ subunits (2.1% total), and complicated structures. Neither mature complexes, nor these novel...
We imaged the interiors of relatively intact Xenopus oocyte nuclei by field emission scanning electron microscopy (feSEM) and visualized a network filaments that attach to nuclear pore complexes extend throughout nucleus. Within nucleus, these `pore-linked filaments' (PLFs) were embedded into spherical structures 100 nm ∼5 μm in diameter. A subset spheres was identified as Cajal bodies immuno-gold labeling; rest inferred be nucleoli snurposomes both which are abundant nuclei. Most PLFs...
Dynamins are a conserved family of proteins involved in membrane fusion and fission. Although mammalian dynamins known to be several membrane-trafficking events, the role dynamin-1 endocytosis is best-characterised this protein family. Despite many similarities between yeast cells, comparable for has not previously been demonstrated. The reported lack involvement raised questions over general applicability current model endocytosis, also precluded studies using well-developed methods yeast,...
The nuclear envelope contains >100 transmembrane proteins that continuously exchange with the endoplasmic reticulum and move within membranes. To better understand organization dynamics of this system, we compared trafficking 15 integral using FRAP. A surprising 30-fold range mobilities was observed. dynamic behavior several these also analyzed after depletion ATP and/or Ran, two functions implicated in reticulum-inner membrane translocation. This revealed ATP- Ran-dependent translocation...
Nuclear envelope complexity is expanding with respect to identification of protein components. Here we test the validity proteomics results that identified 67 novel predicted nuclear transmembrane proteins (NETs) from liver by directly comparing 30 as tagged fusions using targeting assays. This confirmed 21 NETs, but 4 only targeted in certain cell types, underscoring interactions tether NETs envelope. Four accumulated at rim normal fibroblasts not lacking lamin A, suggesting involvement A...
The tardigrade Ramazzottius varieornatus has remarkable resilience to a range of environmental stresses. In this study, we have characterised two members the small heat shock protein (sHSP) family in R. varieornatus, HSP20-3 and HSP20-6. These are most highly upregulated sHSPs response 24 h at 35
ABSTRACT The Nuclear Pore Complex (NPC) regulates nucleocytoplasmic transport by providing small channels for passive diffusion and multiple docking surfaces that lead to a central translocation channel active transport. In this study we have investigated high resolution scanning transmission electron microscopy the dynamics of NPC structure in salivary gland nuclei from Chironomus during Balbiani ring (BR) mRNP translocation, present evidence rearrangement transporter related export....
ABSTRACT The structure of the nuclear pore complex (NPC) has been previously studied by many different electron microscopic techniques. Recently, scanning microscopes have developed that can visualise biologically relevant structural detail at same level resolution as transmission and used to study NPC structure. We such an instrument directly both cytoplasmic nucleoplasmic surfaces manually isolated amphibian oocyte envelopes spread, fixed, critical point dried coated with a thin...
Actin is critical for endocytosis in yeast cells, and also mammalian cells under tension. However, questions remain as to how force generated through actin polymerization transmitted the plasma membrane drive invagination scission. Here, we reveal that dynamin Vps1 binds bundles filamentous actin. Mutational analysis of a helix stalk domain identifies mutant RR457-458EE more weakly. In vivo function demonstrates mutation disrupts but not other functions such vacuolar trafficking or...
Abstract Repo-Man is a protein phosphatase 1 (PP1) targeting subunit that regulates mitotic progression and chromatin remodelling. After mitosis, Repo-Man/PP1 remains associated with but its function in interphase not known. Here we show Repo-Man, via Nup153, enriched on condensed at the nuclear periphery edge of nucleopore basket. formation heterochromatin, dephosphorylates H3S28 it necessary sufficient for heterochromatin binding H3K27me3 recruitment. Using novel proteogenomic approach,...
Pectin is a major component of plant cells walls. The extent to which pectin chains crosslink with one another determines crucial properties including cell wall strength, porosity, and the ability small, biologically significant molecules access cell. Despite its importance, gaps remain in our comprehension, at molecular level, how cross-links influence mechanical physical This study employs multidisciplinary approach, combining dynamics simulations, experimental investigations, mathematical...
The mechanisms of nuclear pore complex (NPC) assembly and disassembly during mitosis in vivo are not well defined. To address this to identify the steps NPC assembly, we investigated Drosophila embryo structure at syncytial stage early development using field emission scanning electron microscopy (FESEM), a high resolution surface imaging technique, transmission microscopy. Nuclear division embryos is characterized by semi-closed mitosis, which membranes ruptured only polar regions arranged...
The lens is an avascular tissue, separated from the aqueous and vitreous humors by its own extracellular matrix, capsule. Here we demonstrate that capsule a source of essential survival factors for epithelial cells. Primary immortalized cells survive in low levels serum are resistant to staurosporine-induced apoptosis when they remain contact with Physical required maximal resistance stress. also soluble including fibroblast growth factor 2 (FGF-2) perlecan, matrix component enhances FGF-2...
Transport across the nuclear envelope is regulated by pore complexes (NPCs). Much understood about factors that shuttle and control movement of cargos through NPC, but less has been resolved translocation process itself. Various models predict how move channel; however, direct observation missing. Therefore, we have developed methods to accurately determine cargo positions within NPC. Cargos were instantly trapped in transit high-pressure freezing, optimally preserved low-temperature...