Rebuilding Cytokinesis One Molecule at a Time

Cells are the fundamental units of life. They make up all living things, from bacteria that live in the soil, to archea that give thermal springs their bright colors, to trees and humans. All of these cells share some common functions: they build themselves from basic building blocks, following the instructions of their genetic blueprint, and...

Biomolecule electrotransfer to mammalian cells

Delivery of biomolecules using pulsed electric fields or electrotransfer has applications such as biomedical engineering, bioprocess engineering and genomic engineering. When a cell is placed in an electric field, the induced transmembrane voltage catalyzes the formation of pores on the cell membrane. This enables the delivery of otherwise cell...

Characterizing the architecture of reconstituted minimal septin and septin-actin cortices at high resolution

In animal cells, cell shape is primarily regulated by the actin cortex, a thin filament network connected to the plasma membrane. The architecture of the cortex is considered a key regulator of its function. Visualising the cortex is difficult due to the high density of numerous small-sized proteins involved in its formation. Consequently, the...

Septin-microtubule association via a motif unique to isoform 1 of septin 9 tunes stress fibers

Septins, a family of GTP-binding proteins that assemble into higher order structures, interface with the membrane, actin filaments and microtubules, and are thus important regulators of cytoarchitecture. Septin 9 (SEPT9), which is frequently overexpressed in tumors and mutated in hereditary neuralgic amyotrophy (HNA), mediates the binding of...

Intermediate Filaments in Cellular Mechanoresponsiveness: Mediating Cytoskeletal Crosstalk From Membrane to Nucleus and Back

The mammalian cytoskeleton forms a mechanical continuum that spans across the cell, connecting the cell surface to the nucleus via transmembrane protein complexes in the plasma and nuclear membranes. It transmits extracellular forces to the cell interior, providing mechanical cues that influence cellular decisions, but also actively generates...

Cross-linkers at growing microtubule ends generate forces that drive actin transport

The actin and microtubule cytoskeletons form active networks in the cell that can contract and remodel, resulting in vital cellular processes such as cell division and motility. Motor proteins play an important role in generating the forces required for these processes, but more recently the concept of passive cross-linkers being able to...

Insights into animal septins using recombinant human septin octamers with distinct SEPT9 isoforms

Septin GTP-binding proteins contribute essential biological functions that range from the establishment of cell polarity to animal tissue morphogenesis. Human septins in cells form hetero-octameric septin complexes containing the ubiquitously expressed SEPT9 subunit (also known as SEPTIN9). Despite the established role of SEPT9 in mammalian...

Optimized cDICE for Efficient Reconstitution of Biological Systems in Giant Unilamellar Vesicles

Giant unilamellar vesicles (GUVs) are often used to mimic biological membranes in reconstitution experiments. They are also widely used in research on synthetic cells, as they provide a mechanically responsive reaction compartment that allows for controlled exchange of reactants with the environment. However, while many methods exist to...

Charge-dependent interactions of monomeric and filamentous actin with lipid bilayers

The cytoskeletal protein actin polymerizes into filaments that are essential for the mechanical stability of mammalian cells. In vitro experiments showed that direct interactions between actin filaments and lipid bilayers are possible and that the net charge of the bilayer as well as the presence of divalent ions in the buffer play an...

A systematic study of macrophages’ response to submicron pillars

Objective: Advances in the field of biomaterials have positively affected implant acceptance and nowadays nanostructured surfaces are known to have a positive effect on bone regeneration. The development of the field of osteoimmunology has contributed to a steadily increasing interest towards the investigation of the immunomodulatory effect of...

Cytolinker Gas2L1 regulates axon morphology through microtubule-modulated actin stabilization

Crosstalk between the actin and microtubule cytoskeletons underlies cellular morphogenesis. Interactions between actin filaments and microtubules are particularly important for establishing the complex polarized morphology of neurons. Here, we characterized the neuronal function of growth arrest-specific 2-like 1 (Gas2L1), a protein that can...

Co-Orientation: Quantifying Simultaneous Co-Localization and Orientational Alignment of Filaments in Light Microscopy

Co-localization analysis is a widely used tool to seek evidence for functional interactions between molecules in different color channels in microscopic images. Here we extend the basic co-localization analysis by including the orientations of the structures on which the molecules reside. We refer to the combination of co-localization of...