Biology subjects

Schmid, V.

Publications and source records attributed to Schmid, V..

2 recordsLinked to original sources

bioRxiv2022

A new monoclonal antibody enables BAR analysis of subcellular importin β1 interactomes

Importin {beta}1 (KPNB1) is a nucleocytoplasmic transport factor with critical roles in both cytoplasmic and nucleocytoplasmic transport, hence there is keen interest in the characterization of its subcellular interactomes. We found limited efficiency of BioID in detection of importin complex cargos, and therefore generated a highly specific and sensitive anti-KPNB1 monoclonal antibody to enable Biotinylation by Antibody Recognition (BAR) analysis of importin {beta}1 interactomes. The monoclonal antibody recognizes an epitope comprising residues 301-320 of human KPBN1, and strikingly is highly specific for cytoplasmic KPNB1 in diverse applications, with little or no reaction with KPNB1 in the nucleus. BAR with this novel antibody revealed numerous new interactors of importin {beta}1, expanding the KPNB1 interactome to cytoplasmic and signaling complexes that highlight potential new functions for the importins complex beyond nucleocytoplasmic transport. Data are available via ProteomeXchange with identifier PXD032728.

neuroscience↗

bioRxiv2019

Cohesin depleted cells pass through mitosis and reconstitute a functional nuclear architecture

Cohesin plays an essential role in chromatin loop extrusion, but its impact on a compartmentalized nuclear architecture, linked to nuclear functions, is debatable. Using live-cell and super-resolved 3D microscopy, we demonstrate that cohesin depleted cells pass through an endomitosis and rebuild a single multilobulated nucleus (MLN) with chromosome territories (CTs) pervaded by interchromatin channels. CTs contain chromatin domain clusters with a zonal organization of repressed chromatin domains in the interior and transcriptionally competent domains located at the periphery. Splicing speckles are located nearby within the lining channel system. These clusters form microscopically defined, active and inactive compartments, which correspond to A/B compartments, detected with ensemble Hi-C. Functionality of MLN despite continuous absence of cohesin was demonstrated by their ability to pass through S-phase with typical spatio-temporal patterns of replication domains. Evidence for structural changes of these domains compared to controls suggests that cohesin is required for their full integrity.

cell biology↗