Matthias Trost

Abstract The Gram-negative β-barrel assembly machinery (BAM) complex catalyses the folding and membrane insertion of newly synthesized β-barrel outer membrane proteins. The BAM is structurally conserved, but most studies have focused on Gammaproteobacteria. Here, using single-particle cryogenic electron microscopy, quantitative proteomics and functional assays, we show that the BAM complex is distinct within the Bacteroidota.

Abstract Cytokines of the TGF-β superfamily control essential cell fate decisions via receptor regulated SMAD (R-SMAD) transcription factors. Ligand-induced R-SMAD phosphorylation in the cytosol triggers their activation and nuclear accumulation. We determine how R-SMADs are inactivated by dephosphorylation in the cell nucleus to counteract signaling by TGF-β superfamily ligands.

Abstract Immune surveillance by cytotoxic T cells eliminates tumor cells and cells infected by intracellular pathogens. This process relies on the presentation of antigenic peptides by Major Histocompatibility Complex class I (MHC-I) at the cell surface. The loading of these peptides onto MHC-I depends on the peptide loading complex (PLC) at the endoplasmic reticulum (ER).