A5075074631- Cellular transport and secretion
- Lipid Membrane Structure and Behavior
- Neuroscience and Neuropharmacology Research
- Erythrocyte Function and Pathophysiology
- Botulinum Toxin and Related Neurological Disorders
- Calcium signaling and nucleotide metabolism
- Neurological disorders and treatments
- Photoreceptor and optogenetics research
- Receptor Mechanisms and Signaling
- Retinal Development and Disorders
- Ion channel regulation and function
- Mitochondrial Function and Pathology
- Advanced Fluorescence Microscopy Techniques
- Hereditary Neurological Disorders
- Endoplasmic Reticulum Stress and Disease
- Genetic Neurodegenerative Diseases
- RNA Interference and Gene Delivery
- Pancreatic function and diabetes
- Nerve injury and regeneration
- Biotin and Related Studies
- Advanced biosensing and bioanalysis techniques
- Venomous Animal Envenomation and Studies
- Microtubule and mitosis dynamics
- Signaling Pathways in Disease
- Glycosylation and Glycoproteins Research
University of Wisconsin–Madison
2016-2025
Howard Hughes Medical Institute
2015-2024
Johns Hopkins Medicine
2023
Johns Hopkins University
2023
University of Copenhagen
2023
Madison Group (United States)
2022
In-Q-Tel
2009
University of Cambridge
2008
The University of Texas Health Science Center at Houston
2006
University Medical Center
2005
How the widely used botulinum neurotoxin A (BoNT/A) recognizes and enters neurons is poorly understood. We found that BoNT/A by binding to synaptic vesicle protein SV2 (isoforms A, B, C). Fragments of harbor toxin interaction domain inhibited from neurons. SV2A SV2B knockout hippocampal was abolished restored expressing SV2A, SV2B, or SV2C. Reduction expression in PC12 Neuro-2a cells also entry BoNT/A, which could be isoforms. Finally, mice lacked an isoform (SV2B) displayed reduced...
We investigated the effect of synaptotagmin I on membrane fusion mediated by neuronal SNARE proteins, SNAP-25, syntaxin, and synaptobrevin, which were reconstituted into vesicles. In presence Ca 2+ , cytoplasmic domain (syt) strongly stimulated when synaptobrevin densities similar to those found in native synaptic The dependence syt-stimulated was modulated changes lipid composition vesicles a truncation that mimics cleavage SNAP-25 botulinum neurotoxin A. Stimulation abolished disrupting...
Colinear HOX expression during hindbrain and spinal cord development diversifies assigns regional neural phenotypes to discrete rhombomeric vertebral domains. Despite the precision of patterning in vivo, vitro approaches for differentiating human pluripotent stem cells (hPSCs) posterior fates coarsely pattern thereby generating cultures broadly specified or regions. Here, we demonstrate that successive activation fibroblast growth factor, Wnt/β-catenin, differentiation factor signaling hPSC...
The function of α-synuclein (α-syn) has been long debated, and two seemingly divergent views have emerged. In one, α-syn binds to VAMP2, acting as a SNARE chaperone—but with no effect on neurotransmission—while another posits that attenuates neurotransmitter release by restricting synaptic vesicle mobilization recycling. Here, we show α-syn–VAMP2 interactions are necessary for α-syn–induced attenuation. Our data connect suggest unified model function.
While there is compelling evidence that the synaptic vesicle protein synaptotagmin serves as major Ca2+ sensor for regulated exocytosis, it not known how binding initiates membrane fusion. Here we report increases affinity, by approximately 2 orders of magnitude, between and syntaxin 1, a component fusion apparatus. This effect specific divalent cations which can stimulate exocytosis vesicles (Ca2+ > Ba2+, Sr2+ Mg2+). The Ca2+-dependence interaction was composed two components with EC50...
The fusion pore of regulated exocytosis is a channel that connects and spans the vesicle plasma membranes. molecular composition this important intermediate structure unknown. Here, we found mutations some residues within transmembrane segment syntaxin (Syx), membrane protein essential for exocytosis, altered neurotransmitter flux through pores conductance. influenced fusion-pore lay along one face an α-helical model. Thus, formed at least in part by circular arrangement 5 to 8 Syx segments membrane.
Syntaxin 1 and synaptosome-associated protein of 25 kD (SNAP-25) are neuronal plasmalemma proteins that appear to be essential for exocytosis synaptic vesicles (SVs). Both form a complex with synaptobrevin, an intrinsic membrane SVs. This binding is thought responsible vesicle docking apparently precedes fusion. According the current concept, syntaxin SNAP-25 members larger families, collectively designated as target-SNAP receptors (t-SNAREs), whose specific localization subcellular...
In the exocytosis of neurotransmitter, fusion pore opening represents first instant fluid contact between vesicle lumen and extracellular space. The existence has been established by electrical measurements, but its molecular composition is unknown. possibility that synaptotagmin regulates pores was investigated with amperometry to monitor single dense-core vesicles. Overexpression I prolonged time from dilation, whereas IV shortened this time. Both isoforms reduced norepinephrine flux...
Botulinum neurotoxins (BoNTs) cause botulism by entering neurons and cleaving proteins that mediate neurotransmitter release; disruption of exocytosis results in paralysis death. The receptors for BoNTs are thought to be composed both gangliosides; however, protein components toxin entry have not been identified. Using gain-of-function loss-of-function approaches, we report here the secretory vesicle proteins, synaptotagmins (syts) I II, BoNT/B (but BoNT/A or E) into PC12 cells. Further,...
The membrane proteins SNAP-25, syntaxin, and synaptobrevin (vesicle-associated protein) have recently been implicated as central elements of an exocytotic fusion complex in neurons. Here we report that SNAP-25 binds directly to both syntaxin synaptobrevin. SNAP-25-binding domain lies between residues 199 243, within the region previously shown mediate binding (Calakos, N., Bennett, M. K., Peterson, K. E., Scheller, R. H. (1994) Science 263, 1146-1149). syntaxin-binding encompasses most...
Synaptotagmin 1 binds Ca2+ and membranes via its C2A-domain plays an essential role in excitation-secretion coupling. In this study, we sought to identify Ca2+- membrane-induced local conformational changes the of synaptotagmin delineate C2A-lipid binding interface. To address these questions native phenylalanine residues were replaced, at each face domain, with tryptophan reporters. Changes tryptophanyl fluorescence indicated that Ca2+induced long range throughout C2A, including regions...
Botulinum neurotoxin E (BoNT/E) can cause paralysis in humans and animals by blocking neurotransmitter release from presynaptic nerve terminals. How this toxin targets enters neurons is not known. Here we identified two isoforms of the synaptic vesicle protein SV2, SV2A SV2B, as receptors for BoNT/E. BoNT/E failed to enter cultured SV2A/B knockout mice; entry was restored expressing or but SV2C. Mice lacking SV2B displayed reduced sensitivity The fourth luminal domain alone, expressed...