Studies

Autophagy is responsible for degradation of an extensive portfolio of cytosolic cargoes that are engulfed in autophagosomes to facilitate their transport to lysosomes. Besides basal autophagy, which constantly degrades cellular material, the pathway is dynamically altered by different conditions, resulting in enhanced autophagosome formation and cargo turnover. The extensive profile of autophagosome content as well as the phospholipid composition of human autophagosome membranes remains elusive. ...

Loss-of-function mutations in CLN3 cause juvenile Batten disease, featuring neurodegeneration and early-stage neuroinflammation. How loss of CLN3 function leads to early neuroinflammation is not yet understood. Here, we have comprehensively studied microglia from Cln3∆ex7/8 mice, a genetically accurate disease model. Loss of CLN3 function in microglia leads to lysosomal storage material accumulation and abnormal morphology of subcellular organelles. Moreover, pathological proteomic signatures are ...

Niemann-Pick type C (NPC) disease is a rare neurodegenerative disorder mainly caused by autosomal recessive mutations in Npc1 which result in abnormal late endosomal/lysosomal lipid storage. Although microgliosis is one of the prominent pathological features, consequences of NPC1 loss on microglial function and disease outcome remain largely unknown. Here, we provide an in-depth characterization of microglial proteomic signatures and phenotypes in an NPC1-deficient (Npc1-/-) murine model. We ...

Cells respond to lysosomal membrane permeabilization by membrane repair or selective macroautophagy of damaged lysosomes, termed lysophagy, but it is not fully understood how this decision is made. Here, we uncover a pathway in human cells that detects lipid bilayer perturbations in the limiting membrane of compromised lysosomes, which fail to be repaired, and then initiates ubiquitin-triggered lysophagy. We find that SPG20 binds the repair factor IST1 on damaged lysosomes and, importantly, ...

The human lysosomal polypeptide ABC transporter TAPL (ABC subfamily B member 9, ABCB9) transports 6–59 amino-acids-long polypeptides from the cytosol into lysosomes. The subcellular localization of TAPL depends solely on its N-terminal transmembrane domain TMD0, which lacks conventional targeting sequences. However, the intracellular route and the molecular mechanisms that control TAPL localization remain unclear. Here, we delineated the route of TAPL to lysosomes and investigated the determinants ...

CD4+ T cells orchestrate both humoral and cytotoxic immune responses. While it is known that CD4+ T cell proliferation relies on autophagy, direct identification of the autophagosomal cargo involved is still missing. Here, we created a transgenic mouse model, which, for the first time, enables us to directly map the proteinaceous content of autophagosomes in any primary cell by LC3 proximity labelling. IL-7Rα, a cytokine receptor mostly found in naïve and memory T cells, was reproducibly detected ...

The complexity of signaling events and cellular responses unfolding in neuronal, glial, and immune cells upon traumatic brain injury (TBI) constitutes an obstacle in elucidating pathophysiological links and targets for intervention. We use array phosphoproteomics in a murine mild blunt TBI to reconstruct the temporal dynamics of tyrosine-kinase signaling in TBI and then scrutinize the large-scale effects of perturbation of Met/HGFR, VEGFR1, and Btk signaling by small molecules. We show Met/HGFR ...