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Öttl M, Toonen RF, Verhage M. Reduced synaptic depression in human neurons carrying homozygous disease-causing STXBP1 variant L446F. Hum Mol Genet 2024; 33:991-1000. [PMID: 38484778 PMCID: PMC11102591 DOI: 10.1093/hmg/ddae035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 02/02/2024] [Indexed: 05/20/2024] Open
Abstract
MUNC18-1 is an essential protein of the regulated secretion machinery. De novo, heterozygous mutations in STXBP1, the human gene encoding this protein, lead to a severe neurodevelopmental disorder. Here, we describe the electrophysiological characteristics of a unique case of STXBP1-related disorder caused by a homozygous mutation (L446F). We engineered this mutation in induced pluripotent stem cells from a healthy donor (STXBP1LF/LF) to establish isogenic cell models. We performed morphological and electrophysiological analyses on single neurons grown on glial micro-islands. Human STXBP1LF/LF neurons displayed normal morphology and normal basal synaptic transmission but increased paired-pulse ratios and charge released, and reduced synaptic depression compared to control neurons. Immunostainings revealed normal expression levels but impaired recognition by a mutation-specific MUNC18-1 antibody. The electrophysiological gain-of-function phenotype is in line with earlier overexpression studies in Stxbp1 null mouse neurons, with some potentially human-specific features. Therefore, the present study highlights important differences between mouse and human neurons critical for the translatability of pre-clinical studies.
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Affiliation(s)
- Miriam Öttl
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam 1081HV, the Netherlands
| | - Ruud F Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam 1081HV, the Netherlands
| | - Matthijs Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, De Boelelaan 1085, Amsterdam 1081HV, the Netherlands
- Department of Human Genetics, Center for Neurogenomics and Cognitive Research, University Medical Center, De Boelelaan 1117, Amsterdam 1081HV, the Netherlands
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Liu Y, Ren C, Zhan R, Cao Y, Ren Y, Zou L, Zhou C, Peng L. Exploring the Potential of Plant-Derived Exosome-like Nanovesicle as Functional Food Components for Human Health: A Review. Foods 2024; 13:712. [PMID: 38472825 DOI: 10.3390/foods13050712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 01/27/2024] [Accepted: 02/19/2024] [Indexed: 03/14/2024] Open
Abstract
Plant-derived exosome-like nanovesicles (PELNs) are bilayer membrane-enclosed nanovesicles secreted by plant cells, serving as carriers of various substances such as proteins, RNA, and metabolites. The mounting evidence suggests that PELN plays a crucial role in transmembrane signaling, nutrient transportation, apoptosis, and regulation of gut microbiota composition. This makes it a promising "dark nutrient" for plants to modulate human physiology and pathogenesis. A comprehensive understanding of PELN formation, uptake, and functional mechanisms can offer novel insights into plant nutrition and functional properties, thereby facilitating the precise development of plant-based foods and drugs. This article provides a summary of PELN extraction and characterization, as well as absorption and delivery processes. Furthermore, it focuses on the latest discoveries and underlying physiological mechanisms of PELN's functions while exploring future research directions.
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Affiliation(s)
- Yizhi Liu
- Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, Chengdu University, Chengdu 610106, China
| | - Chaoqin Ren
- College of Resources and Environment, Aba Teachers University, Wenchuan 623002, China
| | - Ruiling Zhan
- Agricultural Science Research Institute of Tibetan Autonomous Prefecture of Ganzi Prefecture, Kangding 626099, China
| | - Yanan Cao
- Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, Chengdu University, Chengdu 610106, China
| | - Yuanhang Ren
- Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, Chengdu University, Chengdu 610106, China
| | - Liang Zou
- Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, Chengdu University, Chengdu 610106, China
| | - Chuang Zhou
- Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, Chengdu University, Chengdu 610106, China
| | - Lianxin Peng
- Key Laboratory of Coarse Cereal Processing of Ministry of Agriculture and Rural Affairs, Chengdu University, Chengdu 610106, China
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Weeratunga S, Gormal RS, Liu M, Eldershaw D, Livingstone EK, Malapaka A, Wallis TP, Bademosi AT, Jiang A, Healy MD, Meunier FA, Collins BM. Interrogation and validation of the interactome of neuronal Munc18-interacting Mint proteins with AlphaFold2. J Biol Chem 2024; 300:105541. [PMID: 38072052 PMCID: PMC10820826 DOI: 10.1016/j.jbc.2023.105541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 11/27/2023] [Accepted: 11/29/2023] [Indexed: 01/13/2024] Open
Abstract
Munc18-interacting proteins (Mints) are multidomain adaptors that regulate neuronal membrane trafficking, signaling, and neurotransmission. Mint1 and Mint2 are highly expressed in the brain with overlapping roles in the regulation of synaptic vesicle fusion required for neurotransmitter release by interacting with the essential synaptic protein Munc18-1. Here, we have used AlphaFold2 to identify and then validate the mechanisms that underpin both the specific interactions of neuronal Mint proteins with Munc18-1 as well as their wider interactome. We found that a short acidic α-helical motif within Mint1 and Mint2 is necessary and sufficient for specific binding to Munc18-1 and binds a conserved surface on Munc18-1 domain3b. In Munc18-1/2 double knockout neurosecretory cells, mutation of the Mint-binding site reduces the ability of Munc18-1 to rescue exocytosis, and although Munc18-1 can interact with Mint and Sx1a (Syntaxin1a) proteins simultaneously in vitro, we find that they have mutually reduced affinities, suggesting an allosteric coupling between the proteins. Using AlphaFold2 to then examine the entire cellular network of putative Mint interactors provides a structural model for their assembly with a variety of known and novel regulatory and cargo proteins including ADP-ribosylation factor (ARF3/ARF4) small GTPases and the AP3 clathrin adaptor complex. Validation of Mint1 interaction with a new predicted binder TJAP1 (tight junction-associated protein 1) provides experimental support that AlphaFold2 can correctly predict interactions across such large-scale datasets. Overall, our data provide insights into the diversity of interactions mediated by the Mint family and show that Mints may help facilitate a key trigger point in SNARE (soluble N-ethylmaleimide-sensitive factor attachment receptor) complex assembly and vesicle fusion.
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Affiliation(s)
- Saroja Weeratunga
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Meihan Liu
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Denaye Eldershaw
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Emma K Livingstone
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Anusha Malapaka
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Tristan P Wallis
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Adekunle T Bademosi
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Anmin Jiang
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia
| | - Michael D Healy
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia
| | - Frederic A Meunier
- Clem Jones Centre for Ageing and Dementia Research, Queensland Brain Institute, The University of Queensland, Queensland, Australia; School of Biomedical Sciences, The University of Queensland, Queensland, Australia
| | - Brett M Collins
- Institute for Molecular Bioscience, The University of Queensland, Queensland, Australia.
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