Biology subjects

van Bommel, N.

Publications and source records attributed to van Bommel, N..

3 recordsLinked to original sources

bioRxiv2022

Mapping localization of 21 endogenous proteins in the Golgi apparatus of rodent neurons

The Golgi apparatus is the major sorting hub in the secretory pathway and particularly important for protein sorting in neurons. Knowledge about protein localization in Golgi compartments is largely based on work in cell lines. Here, we systematically compared protein localization of 21 endogenous proteins in the Golgi apparatus of mouse neurons using confocal microscopy and line scan analysis. We localized these proteins by measuring the distance relative to the canonical TGN marker TGN38. Based on this, proteins fell into three groups: upstream of, overlapping with or downstream of TGN38. Seven proteins showed complete overlap with TGN38, while proteins downstream of TGN38 were located at varying distances from TGN38. Proteins upstream of TGN38 were localized in between TGN38 and the cis-/medial Golgi markers Giantin and GM130. This localization was consistent with protein function. Our data provide an overview of the relative localization of endogenous proteins in the Golgi of primary mouse neurons.

cell biology↗

bioRxiv2022

Distinct nano-structures support a multifunctional role of actin at presynapses

Synapses are the nexus of signal transmission in the nervous system. Despite decades of work, the architecture of the actin cytoskeleton that concentrates at presynapses remain poorly known, hindering our comprehensive understanding of its roles in presynaptic physiology. In this work, we take advantage of a validated model of bead-induced presynapses to measure and visualize isolated presynaptic actin by diffraction-limited and super-resolution microscopy. We first identify a major population of actin-enriched presynapses that concentrates more presynaptic components, and shows higher synaptic vesicle cycling than their non-enriched counterparts. Using pharmacological perturbations, we determine that an optimal amount of actin is necessary for this effect of actin enrichment. Modulation of this effect by actin nucleation inhibitors indicates its dependance on distinct presynaptic actin assemblies. Using Single Molecule Localization Microscopy (SMLM), we directly visualize these nano-structures in isolated presynapses, defining an actin mesh at the active zone, actin rails between the active zone and deeper reserve pools, and actin corrals around the whole presynaptic compartment. We finally show that these three types of presynaptic actin nano-structures are differentially affected by actin nucleation inhibitors, consistent with their effect on presynaptic component concentration and on synaptic vesicle cycling.

neuroscience↗

bioRxiv2017

Robust and Bright Genetically Encoded Fluorescent Markers for Highlighting Structures and Compartments in Mammalian Cells

To increase our understanding of the inner working of cells, there is a need for specific markers to identify biomolecules, cellular structures and compartments. One type of markers comprises genetically encoded fluorescent probes that are linked with protein domains, peptides and/or signal sequences. These markers are encoded on a plasmid and they allow straightforward, convenient labeling of cultured mammalian cells by introducing the plasmid into the cells. Ideally, the fluorescent marker combines favorable spectroscopic properties (brightness, photostability) with specific labeling of the structure or compartment of interest. Here, we report our ongoing efforts to generate robust and bright genetically encoded fluorescent markers for highlighting structures and compartments in living cells. The plasmids are distributed by addgene: https://www.addgene.org/browse/article/28189953/ O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=71 SRC="FIGDIR/small/160374v2_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@67f3aaorg.highwire.dtl.DTLVardef@ae2235org.highwire.dtl.DTLVardef@47f729org.highwire.dtl.DTLVardef@b3c9d1_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗