AI Article Synopsis
- The process by which cells create distinct plasma membrane domains is not fully known, but previous research indicates that microvilli are restricted to the apical side of epithelial cells through the activation of the protein ezrin.
- A multi-step mechanism involving the kinase LOK specifically phosphorylates ezrin, allowing it to function correctly.
- This mechanism includes conformational changes triggered by PIP binding to ezrin, which enables the LOK kinase to precisely target a specific threonine residue for phosphorylation at the plasma membrane, ensuring high specificity.
Article Abstract
How cells specify morphologically distinct plasma membrane domains is poorly understood. Prior work has shown that restriction of microvilli to the apical aspect of epithelial cells requires the localized activation of the membrane-F-actin linking protein ezrin. Using an system, we now define a multi-step process whereby the kinase LOK specifically phosphorylates ezrin to activate it. Binding of PIP to ezrin induces a conformational change permitting the insertion of the LOK C-terminal domain to wedge apart the membrane and F-actin-binding domains of ezrin. The N-terminal LOK kinase domain can then access a site 40 residues distal from the consensus sequence that collectively direct phosphorylation of the appropriate threonine residue. We suggest that this elaborate mechanism ensures that ezrin is only phosphorylated at the plasma membrane, and with high specificity by the apically localized kinase LOK.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5400502 | PMC |
| http://dx.doi.org/10.7554/eLife.22759 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Synapse-specific catecholaminergic modulation of neuronal glutamate release.
Proc Natl Acad Sci U S A
January 2025
Helen Wills Neuroscience Institute, University of California Berkeley, Berkeley, CA 94720.
Norepinephrine in vertebrates and its invertebrate analog, octopamine, regulate the activity of neural circuits. We find that, when hungry, larvae switch activity in type II octopaminergic motor neurons (MNs) to high-frequency bursts, which coincide with locomotion-driving bursts in type I glutamatergic MNs that converge on the same muscles. Optical quantal analysis across hundreds of synapses simultaneously reveals that octopamine potentiates glutamate release by tonic type Ib MNs, but not phasic type Is MNs, and occurs via the G-coupled octopamine receptor (OAMB).
View Article and Find Full Text PDFIntegrin-activating protein Invasin sustains long-term expansion of primary epithelial cells as 2D organoid sheets.
Proc Natl Acad Sci U S A
January 2025
Oncode Institute, Hubrecht Institute-Royal Netherlands Academy of Arts and Science, Utrecht 3584 CT, The Netherlands.
Matrigel/BME, a basement membrane-like preparation, supports long-term growth of epithelial 3D organoids from adult stem cells [T. Sato , , 262-265 (2009); T. Sato , , 1762-1772 (2011)].
View Article and Find Full Text PDFA lever hypothesis for Synaptotagmin-1 action in neurotransmitter release.
Proc Natl Acad Sci U S A
January 2025
Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX 75390.
Neurotransmitter release is triggered in microseconds by Ca-binding to the Synaptotagmin-1 C-domains and by SNARE complexes that form four-helix bundles between synaptic vesicles and plasma membranes, but the coupling mechanism between Ca-sensing and membrane fusion is unknown. Release requires extension of SNARE helices into juxtamembrane linkers that precede transmembrane regions (linker zippering) and binding of the Synaptotagmin-1 CB domain to SNARE complexes through a "primary interface" comprising two regions (I and II). The Synaptotagmin-1 Ca-binding loops were believed to accelerate membrane fusion by inducing membrane curvature, perturbing lipid bilayers, or helping bridge the membranes, but SNARE complex binding through the primary interface orients the Ca-binding loops away from the fusion site, hindering these putative activities.
View Article and Find Full Text PDFOppositional and competitive instigation of hippocampal synaptic plasticity by the VTA and locus coeruleus.
Proc Natl Acad Sci U S A
January 2025
Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum 44780, Germany.
The novelty, saliency, and valency of ongoing experiences potently influence the firing rate of the ventral tegmental area (VTA) and the locus coeruleus (LC). Associative experience, in turn, is recorded into memory by means of hippocampal synaptic plasticity that is regulated by noradrenaline sourced from the LC, and dopamine, sourced from both the VTA and LC. Two persistent forms of synaptic plasticity, long-term potentiation (LTP), and long-term depression (LTD) support the encoding of different kinds of spatial experience.
View Article and Find Full Text PDFAltering the intracellular trafficking of Necator americanus GST-1 antigen yields novel hookworm mRNA vaccine candidates.
PLoS Negl Trop Dis
January 2025
Department of Pediatrics, National School of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America.
Background: The antigen Na-GST-1, expressed by the hookworm Necator americanus, plays crucial biochemical roles in parasite survival. This study explores the development of mRNA vaccine candidates based on Na-GST-1, building on the success of recombinant Na-GST-1 (rNa-GST-1) protein, currently assessed as a subunit vaccine candidate, which has shown promise in preclinical and clinical studies.
Methodology/findings: By leveraging the flexible design of RNA vaccines and protein intracellular trafficking signal sequences, we developed three variants of Na-GST-1 as native (cytosolic), secretory, and plasma membrane-anchored (PM) antigens.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!