Alpha-synuclein is known to bind to small unilamellar vesicles (SUVs) via its N terminus, which forms an amphipathic alpha-helix upon membrane interaction. Here we show that calcium binds to the C terminus of alpha-synuclein, therewith increasing its lipid-binding capacity. Using CEST-NMR, we reveal that alpha-synuclein interacts with isolated synaptic vesicles with two regions, the N terminus, already known from studies on SUVs, and additionally via its C terminus, which is regulated by the binding of calcium. Indeed, dSTORM on synaptosomes shows that calcium mediates the localization of alpha-synuclein at the pre-synaptic terminal, and an imbalance in calcium or alpha-synuclein can cause synaptic vesicle clustering, as seen ex vivo and in vitro. This study provides a new view on the binding of alpha-synuclein to synaptic vesicles, which might also affect our understanding of synucleinopathies.

Utilizing metal-organic frameworks (MOFs) as a biological carrier can lower the amount of the active pharmaceutical ingredient (API) required in cancer treatments to provide a more efficacious therapy. In this work, we have developed a temperature treatment process for delaying the release of a model drug compound from the pores of NU-1000 and NU-901, while taking care to utilize these MOFs' large pore volume and size to achieve exceptional model drug loading percentages over 35 wt %. Video-rate super-resolution microscopy reveals movement of MOF particles when located outside of the cell boundary, and their subsequent immobilization when taken up by the cell. Through the use of optical sectioning structured illumination microscopy (SIM), we have captured high-resolution 3D images showing MOF uptake by HeLa cells over a 24 h period. We found that addition of a model drug compound into the MOF and the subsequent temperature treatment process does not affect the rate of MOF uptake by the cell. Endocytosis analysis revealed that MOFs are internalized by active transport and that inhibiting the caveolae-mediated pathway significantly reduced cellular uptake of MOFs. Encapsulation of an anticancer therapeutic, alpha-cyano-4-hydroxycinnamic acid (α-CHC), and subsequent temperature treatment produced loadings of up to 81 wt % and demonstrated efficacy at killing cells beyond the burst release effect.

The endoplasmic reticulum (ER), a network of membranous sheets and pipes, supports functions encompassing biogenesis of secretory proteins and delivery of functional solutes throughout the cell. Molecular mobility through the ER network enables these functionalities, but diffusion alone is not sufficient to explain luminal transport across supramicrometre distances. Understanding the ER structure-function relationship is critical in light of mutations in ER morphology-regulating proteins that give rise to neurodegenerative disorders. Here, super-resolution microscopy and analysis of single particle trajectories of ER luminal proteins revealed that the topological organization of the ER correlates with distinct trafficking modes of its luminal content: with a dominant diffusive component in tubular junctions and a fast flow component in tubules. Particle trajectory orientations resolved over time revealed an alternating current of the ER contents, while fast ER super-resolution identified energy-dependent tubule contraction events at specific points as a plausible mechanism for generating active ER luminal flow. The discovery of active flow in the ER has implications for timely ER content distribution throughout the cell, particularly important for cells with extensive ER-containing projections such as neurons.

Current advances in materials science have resulted in the rapid emergence of thousands of functional adsorbent materials in recent years. This clearly creates multiple opportunities for their potential application, but it also creates the following challenge: how does one identify the most promising structures, among the thousands of possibilities, for a particular application? Here, we present a case of computer-aided material discovery, in which we complete the full cycle from computational screening of metal–organic framework materials for oxygen storage, to identification, synthesis and measurement of oxygen adsorption in the top-ranked structure. We introduce an interactive visualization concept to analyze over 1000 unique structure–property plots in five dimensions and delimit the relationships between structural properties and oxygen adsorption performance at different pressures for 2932 already-synthesized structures. We also report a world-record holding material for oxygen storage, UMCM-152, which delivers 22.5% more oxygen than the best known material to date, to the best of our knowledge.

Mitochondria play a key role in oncogenesis and constitute one of the most important targets for cancer treatments. Although the most effective way to deliver drugs to mitochondria is by covalently linking them to a lipophilic cation, the in vivo delivery of free drugs still constitutes a critical bottleneck. Herein, we report the design of a mitochondria-targeted metal−organic framework (MOF) that greatly increases the efficacy of a model cancer drug, reducing the required dose to less than 1% compared to the free drug and ca. 10% compared to the nontargeted MOF. The performance of the system is evaluated using a holistic approach ranging from microscopy to transcriptomics. Super-resolution microscopy of MCF-7 cells treated with the targeted MOF system reveals important mitochondrial morphology changes that are clearly associated with cell death as soon as 30 min after incubation. Whole transcriptome analysis of cells indicates widespread changes in gene expression when treated with the MOF system, specifically in biological processes that have a profound effect on cell physiology and that are related to cell death. We show how targeting MOFs toward mitochondria represents a valuable strategy for the development of new drug delivery systems.

The endoplasmic reticulum (ER) comprises morphologically and functionally distinct domains: sheets and interconnected tubules. These domains undergo dynamic reshaping in response to changes in the cellular environment. However, the mechanisms behind this rapid remodeling are largely unknown. Here, we report that ER remodeling is actively driven by lysosomes, following lysosome repositioning in response to changes in nutritional status: The anchorage of lysosomes to ER growth tips is critical for ER tubule elongation and connection. We validate this causal link via the chemo- and optogenetically driven repositioning of lysosomes, which leads to both a redistribution of the ER tubules and a change of its global morphology. Therefore, lysosomes sense metabolic change in the cell and regulate ER tubule distribution accordingly. Dysfunction in this mechanism during axonal extension may lead to axonal growth defects. Our results demonstrate a critical role of lysosome-regulated ER dynamics and reshaping in nutrient responses and neuronal development.

is an advantageous therapeutic strategy to lower dangerous genetic over-expression. However, the molecules responsible for initiating this process are unstable. Porous nanoparticles called metal-organic frameworks can encapsulate, protect, and deliver these compounds efficaciously without the need for chemical modifications-commonly done to enhance stability. By applying this platform technology, this work demonstrates the successful reduction in expression of a gene by avoiding retention and subsequent degradation in cellular compartments.

28The endoplasmic reticulum (ER) comprises morphologically and functionally distinct domains, 29 sheets and interconnected tubules. These domains undergo dynamic reshaping, in response to 30 changes in the cellular environment. However, the mechanisms behind this rapid remodeling 31 within minutes are largely unknown. Here, we report that ER remodeling is actively driven by 32 lysosomes, following lysosome repositioning in response to changes in nutritional status. The 33 anchorage of lysosomes to ER growth tips is critical for ER tubule elongation and connection. We 34 validate this causal link via the chemo-and optogenetically driven re-positioning of lysosomes, 35 which leads to both a redistribution of the ER tubules and its global morphology. Lysosomes sense 36 metabolic change in the cell and regulate ER tubule distribution accordingly. Dysfunction in this 37 mechanism during axonal extension may lead to axonal growth defects. Our results demonstrate a 38 critical role of lysosome-regulated ER dynamics and reshaping in nutrient responses and neuronal 39 development. 40 41 Main text 42 43The structure of the ER is constantly adapted for the particular needs of the cell (1): the dynamic 44 transitions between ER sheets and tubules allow it to rapidly respond to the changing cellular 45 environment. A group of ER-shaping proteins have been identified as maintaining ER morphology 46 (1), mutations in which are linked to diseases such as hereditary spastic paraplegias (HSPs) (2). 47 (3, 4). Previous work has shown that ER tubule elongation can be driven by three mechanisms: 1/ 50 force generation by motors moving along microtubules (5), which can be classified as sliding, 2/ 51 coupling to microtubule growth using a tip assembly complex (TAC), and 3/ hitchhiking by 52 connecting to other organelles. Whether such reshaping in local domains of the ER tubules could 53 lead to the global reorganization and redistribution of ER remains an open question, and, if this is 54 the case, how is this process regulated? The ER is known to contact other motile organelles, 55 including endosomes, lysosomes, mitochondria, peroxisomes et cetera (6). Among these, 56 lysosomes are particularly interesting, as they make a great number of contacts with the ER (7) 57 and their positioning is regulated by different nutritional status (8). Although ER has been reported 58 to regulate lysosome motions (9), it is not clear whether lysosomes can modulate ER reshaping 59 and distribution, for example via coupled motion (4). We hypothesized that a causal link exists 60 between lysosome motion and ER redistributing and asked whether this provides a mechanism for 61 ER morphological response to nutritional status, given that lysosomes are known to act as signaling 62 hubs for metabolic sensing (10). 63 We first investigated the correlation of motions between lysosomes and the ER network by rapid 64 live-cell imaging. We visualized ER with GFP-tagged vesicle-associated membrane protein-65 associated protein A (VAP...