Publications by authors named "Patrick Frei"
Rapid homeostatic modulation of transsynaptic nanocolumn rings.
Proc Natl Acad Sci U S A
November 2022
Robust neural information transfer relies on a delicate molecular nano-architecture of chemical synapses. Neurotransmitter release is controlled by a specific arrangement of proteins within presynaptic active zones. How the specific presynaptic molecular architecture relates to postsynaptic organization and how synaptic nano-architecture is transsynaptically regulated to enable stable synaptic transmission remain enigmatic.
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- The alpha-proteobacterium Wolbachia pipientis influences its host's reproductive biology to ensure its own transmission, but studying it has been challenging due to its strict growth requirements and limited genetic tools.
- Researchers have determined the structure of Wolbachia's alpha-DsbA1 protein, which is crucial for the oxidative folding of proteins and demonstrates the highest reducing potential among characterized DsbA enzymes.
- Unlike its E. coli counterpart, Wolbachia's alpha-DsbA1 has distinct surface traits and a specialized function, laying the groundwork for future chemical genetics experiments.
Article Synopsis
- Wolbachia pipientis are bacteria that manipulate the reproductive systems of their host insects to improve their transmission, acting as reproductive parasites.* -
- The study focused on the protein alpha-DsbA1, which is believed to play a role in stabilizing other proteins through disulfide bonding, and was successfully cloned, expressed, and purified from E. coli.* -
- Findings revealed that alpha-DsbA1 functions as an oxidant rather than an isomerase, providing insights into its role and paving the way for future studies on its protein interactions and structural properties.*
Article Synopsis
- In Gram-negative bacteria, DsbA introduces disulfide bonds in proteins within the periplasm, while Gram-positive bacteria like Staphylococcus aureus only have one Dsb protein, SaDsbA, which lacks the DsbB partner.
- The crystal structure of SaDsbA shows differences compared to EcDsbA from E. coli, highlighting distinct substrate specificity and a unique binding groove.
- Thermodynamic studies reveal that the oxidized and reduced forms of SaDsbA are equally stable, allowing for potential direct re-oxidation by extracellular oxidants, bypassing the need for DsbB.
DsbD from Escherichia coli catalyzes the transport of electrons from cytoplasmic thioredoxin to the periplasmic disulfide isomerase DsbC. DsbD contains two periplasmically oriented domains at the N- and C-terminus (nDsbD and cDsbD) that are connected by a central transmembrane (TM) domain. Each domain contains a pair of cysteines that are essential for catalysis.
View Article and Find Full Text PDFThe thiol-disulfide oxidoreductase ERp57 is a soluble protein of the endoplasmic reticulum and the closest known homologue of protein disulfide isomerase. The protein interacts with the two lectin chaperones calnexin and calreticulin and thereby promotes the oxidative folding of newly synthesized glycoproteins. Here we have characterized several fundamental structural and functional properties of ERp57 in vitro, such as the domain organization, shape, redox potential, and the ability to catalyze different thiol-disulfide exchange reactions.
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