A5042857590- Endoplasmic Reticulum Stress and Disease
- Ubiquitin and proteasome pathways
- Cellular transport and secretion
- RNA and protein synthesis mechanisms
- Genetics, Bioinformatics, and Biomedical Research
- Glycosylation and Glycoproteins Research
- Pancreatic function and diabetes
- Bacterial Genetics and Biotechnology
- Fungal and yeast genetics research
- RNA modifications and cancer
- Bacteriophages and microbial interactions
- Autophagy in Disease and Therapy
- Biochemical and Molecular Research
- Peptidase Inhibition and Analysis
- Monoclonal and Polyclonal Antibodies Research
- Malaria Research and Control
- Protein Degradation and Inhibitors
- Toxin Mechanisms and Immunotoxins
- ATP Synthase and ATPases Research
- Lysosomal Storage Disorders Research
- Viral Infectious Diseases and Gene Expression in Insects
- Metabolism and Genetic Disorders
- Signaling Pathways in Disease
- Transgenic Plants and Applications
- Lipid Membrane Structure and Behavior
Saarland University
2015-2024
University of Trento
2008
University of Cambridge
1999-2007
Medical Research Council
1997-2004
Wellcome Trust
1999-2004
Addenbrooke's Hospital
1999-2003
Colorado State University
2000
MRC Laboratory for Molecular Cell Biology
1997-1998
University College London
1997-1998
University of California, Berkeley
1992-1994
Protein disulfide isomerase (PDI) interacts with secretory proteins, irrespective of their thiol content, late during translocation into the ER; thus, PDI may be part quality control machinery in ER. We used yeast pdi1 mutants deletions putative peptide binding region molecule to investigate its role recognition misfolded proteins ER and export cytosol for degradation. Our deletion are deficient a cysteine-free protein across membrane degradation, but ER-to-Golgi complex transport properly...
Signal recognition particle (SRP) plays the key role in targeting secretory proteins to membrane of endoplasmic reticulum (Walter, P., and V. R. Lingappa. 1986. Annu. Rev. Cell Biol. 2:499-516). It consists SRP7S RNA six proteins. The 54-kD protein SRP (SRP54) recognizes signal sequence nascent polypeptides. 19-kD (SRP19) binds directly is required for binding SRP54 particle. We used deletion mutants SRP19 an vitro assembly assay presence define regions both which are form a...
Cytotoxic proteins such as ricin A chain (RTA) have target substrates in the cytosol and therefore to reach this cellular compartment order act. RTA is thought translocate into from lumen of endoplasmic reticulum (ER), although how it traverses ER membrane has not been established. Using yeast mutants defective various aspects ER‐associated protein degradation (ERAD) pathway, we show that introduced subverts pathway enter via Sec61p translocon. significant proportion exported avoided...
The dementia familial encephalopathy with neuroserpin inclusion bodies (FENIB) is caused by the accumulation of mutant within neurons (Davis, R. L., Shrimpton, A. E., Holohan, P. D., Bradshaw, C., Feiglin, Sonderegger, P., Kinter, J., Becker, L. M., Lacbawan, F., Krasnewich, Muenke, Lawrence, D. A., Yerby, M. S., Shaw, C.-M., Gooptu, B., Elliott, R., Finch, J. T., Carrell, W., and Lomas, (1999) Nature 401, 376–379), but little known about trafficking wild type neuroserpins. We have...
X-linked retinoschisis results in visual loss early life with splitting within the inner retinal layers. Many missense and protein truncating mutations of causative gene RS1 (encoding retinoschisin) have been identified but disease severity is not mutation-dependent. Retinoschisin a soluble secretory predicted to globular conformation. Missense would be expected interfere folding leading an abnormal conformation intracellular retention elimination. To test this hypothesis we expressed seven...
Familial encephalopathy with neuroserpin inclusion bodies (FENIB) is an autosomal dominant dementia that characterized by the retention of polymers as inclusions within endoplasmic reticulum (ER) neurons. We have developed monoclonal antibodies detect polymerized and used COS-7 cells, stably transfected PC12 cell lines transgenic Drosophila melanogaster to characterize cellular handling all four mutant forms cause FENIB. show a direct correlation between severity disease-causing mutation...
We describe a detailed morphological characterization of the endocytic pathway in differentiating chicken erythroblasts transformed by temperature-sensitive mutant avian erythroblastosis virus (AEV). These cells express high levels transferrin receptors (TfR) when induced to differentiate at 42 degrees C. Biochemical analysis showed that most (approximately 90%) internalized 125I-Tf recycled within approximately 30 min while smaller fraction required up 2 h for recycling. By...
The maltose regulon of Escherichia coli comprises several operons that are under common regulatory control the MalT activator protein. Five mal genes, organized in two divergent operons, code for a binding-protein-dependent transport system specific and maltodextrins. MalK, one subunits this system, not only is essential but also plays role regulation. Mutations abolishing MalK function result inability to cause constitutive expression regulon. For constitutivity be exerted, an additional...
Secretory proteins that fail to fold in the endoplasmic reticulum (ER) are transported back cytosol and degraded by proteasomes. It remains unclear how cell distinguishes between folding intermediates misfolded proteins. We asked whether secretory covalently modified ER before export. found a fraction of mutant alpha-factor precursor, but not wild type, was progressively O-mannosylated microsomes intact yeast cells protein O-mannosyl transferase 2 (Pmt2p). O-Mannosylation increased...
The evolutionarily conserved Sec61 protein complex mediates the translocation of secretory proteins into endoplasmic reticulum. To investigate role Sec61p, which is main subunit this complex, we generated recessive, cold-sensitive alleles ofsec61 that encode stably expressed with strong defects in translocation. stage at posttranslational was blocked probed by chemical crosslinking radiolabeled precursors added to membranes isolated from wild-type and mutant strains. Two classes sec61mutants...
Biogenesis of secretory proteins requires their translocation into the endoplasmic reticulum (ER) through Sec61 channel. Proteins that fail to fold are transported back cytosol and degraded by proteasomes. For many substrates this retrograde transport is affected mutations in channel, can be promoted ATP 19S regulatory particle proteasome, which binds directly channel via its base. Here, we identify SEC61 reduce proteasome binding demonstrate proteasomes ribosomes bind differently cytosolic...
Abstract The 54 kDa subunit of the signal recognition particle (SRP54) binds to sequences nascent secretory and membrane proteins it contributes targeting these precursors endoplasmic reticulum (ER). At ER membrane, binding (SRP) its receptor triggers release SRP54 from bound sequence polypeptide is transferred Sec61 translocon for insertion into, or translocation across, membrane. In current article, we have characterized specificity anti-SRP54 autoantibodies, which are highly...
Protein and peptide export from the Saccharomyces cerevisiae endoplasmic reticulum was examined in vitro using secretory protein pro-alpha-factor a synthetic tripeptide containing acceptor site for N-linked glycosylation as substrates. The release of both glycosylated glycotripeptide dependent on cytosol, temperature, ATP. Antibodies against two proteins essential formation transport vesicles, Sec23p p105, inhibited glyco-pro-alpha-factor exit but did not affect tripeptide. Furthermore,...
Secretory proteins are translocated across the endoplasmic reticulum (ER) membrane through a channel formed by three proteins, namely Sec61p, Sbh1p, and Sss1p (Johnson, A. E., van Waes, M. (1999) Annu. Rev. Cell Dev. Biol. 15, 799–842). Sec61p essential for translocation (Esnault, Y., Blondel, O., Deshaies, R. J., Schekman, R., Kepes, F. (1993) EMBO J. 12, 4083–4093). is polytopic protein that lines channel. The role of unknown. During import into ER channel, many N-glycosylated before...