Electrical synapse structure requires distinct isoforms of a postsynaptic scaffold.
Electrical synapses are neuronal gap junction (GJ) channels associated with a macromolecular complex called the electrical synapse density (ESD), which regulates development and dynamically modifies electrical transmission. However, the proteomic makeup and molecular mechanisms utilized by the ESD t...
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Public Library of Science (PLoS)
2023-11-01
|
| Series: | PLoS Genetics |
| Online Access: | https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1011045&type=printable |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850199441876713472 |
|---|---|
| author | Jennifer Carlisle Michel Margaret M B Grivette Amber T Harshfield Lisa Huynh Ava P Komons Bradley Loomis Kaitlan McKinnis Brennen T Miller Ethan Q Nguyen Tiffany W Huang Sophia Lauf Elias S Michel Mia E Michel Jane S Kissinger Audrey J Marsh William E Crow Lila E Kaye Abagael M Lasseigne Rachel M Lukowicz-Bedford Dylan R Farnsworth E Anne Martin Adam C Miller |
| author_facet | Jennifer Carlisle Michel Margaret M B Grivette Amber T Harshfield Lisa Huynh Ava P Komons Bradley Loomis Kaitlan McKinnis Brennen T Miller Ethan Q Nguyen Tiffany W Huang Sophia Lauf Elias S Michel Mia E Michel Jane S Kissinger Audrey J Marsh William E Crow Lila E Kaye Abagael M Lasseigne Rachel M Lukowicz-Bedford Dylan R Farnsworth E Anne Martin Adam C Miller |
| author_sort | Jennifer Carlisle Michel |
| collection | DOAJ |
| description | Electrical synapses are neuronal gap junction (GJ) channels associated with a macromolecular complex called the electrical synapse density (ESD), which regulates development and dynamically modifies electrical transmission. However, the proteomic makeup and molecular mechanisms utilized by the ESD that direct electrical synapse formation are not well understood. Using the Mauthner cell of zebrafish as a model, we previously found that the intracellular scaffolding protein ZO1b is a member of the ESD, localizing postsynaptically, where it is required for GJ channel localization, electrical communication, neural network function, and behavior. Here, we show that the complexity of the ESD is further diversified by the genomic structure of the ZO1b gene locus. The ZO1b gene is alternatively initiated at three transcriptional start sites resulting in isoforms with unique N-termini that we call ZO1b-Alpha, -Beta, and -Gamma. We demonstrate that ZO1b-Beta and ZO1b-Gamma are broadly expressed throughout the nervous system and localize to electrical synapses. By contrast, ZO1b-Alpha is expressed mainly non-neuronally and is not found at synapses. We generate mutants in all individual isoforms, as well as double mutant combinations in cis on individual chromosomes, and find that ZO1b-Beta is necessary and sufficient for robust GJ channel localization. ZO1b-Gamma, despite its localization to the synapse, plays an auxiliary role in channel localization. This study expands the notion of molecular complexity at the ESD, revealing that an individual genomic locus can contribute distinct isoforms to the macromolecular complex at electrical synapses. Further, independent scaffold isoforms have differential contributions to developmental assembly of the interneuronal GJ channels. We propose that ESD molecular complexity arises both from the diversity of unique genes and from distinct isoforms encoded by single genes. Overall, ESD proteomic diversity is expected to have critical impacts on the development, structure, function, and plasticity of electrical transmission. |
| format | Article |
| id | doaj-art-d248fc86adaa456a9e2ad5a07340bcaf |
| institution | OA Journals |
| issn | 1553-7390 1553-7404 |
| language | English |
| publishDate | 2023-11-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Genetics |
| spelling | doaj-art-d248fc86adaa456a9e2ad5a07340bcaf2025-08-20T02:12:37ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042023-11-011911e101104510.1371/journal.pgen.1011045Electrical synapse structure requires distinct isoforms of a postsynaptic scaffold.Jennifer Carlisle MichelMargaret M B GrivetteAmber T HarshfieldLisa HuynhAva P KomonsBradley LoomisKaitlan McKinnisBrennen T MillerEthan Q NguyenTiffany W HuangSophia LaufElias S MichelMia E MichelJane S KissingerAudrey J MarshWilliam E CrowLila E KayeAbagael M LasseigneRachel M Lukowicz-BedfordDylan R FarnsworthE Anne MartinAdam C MillerElectrical synapses are neuronal gap junction (GJ) channels associated with a macromolecular complex called the electrical synapse density (ESD), which regulates development and dynamically modifies electrical transmission. However, the proteomic makeup and molecular mechanisms utilized by the ESD that direct electrical synapse formation are not well understood. Using the Mauthner cell of zebrafish as a model, we previously found that the intracellular scaffolding protein ZO1b is a member of the ESD, localizing postsynaptically, where it is required for GJ channel localization, electrical communication, neural network function, and behavior. Here, we show that the complexity of the ESD is further diversified by the genomic structure of the ZO1b gene locus. The ZO1b gene is alternatively initiated at three transcriptional start sites resulting in isoforms with unique N-termini that we call ZO1b-Alpha, -Beta, and -Gamma. We demonstrate that ZO1b-Beta and ZO1b-Gamma are broadly expressed throughout the nervous system and localize to electrical synapses. By contrast, ZO1b-Alpha is expressed mainly non-neuronally and is not found at synapses. We generate mutants in all individual isoforms, as well as double mutant combinations in cis on individual chromosomes, and find that ZO1b-Beta is necessary and sufficient for robust GJ channel localization. ZO1b-Gamma, despite its localization to the synapse, plays an auxiliary role in channel localization. This study expands the notion of molecular complexity at the ESD, revealing that an individual genomic locus can contribute distinct isoforms to the macromolecular complex at electrical synapses. Further, independent scaffold isoforms have differential contributions to developmental assembly of the interneuronal GJ channels. We propose that ESD molecular complexity arises both from the diversity of unique genes and from distinct isoforms encoded by single genes. Overall, ESD proteomic diversity is expected to have critical impacts on the development, structure, function, and plasticity of electrical transmission.https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1011045&type=printable |
| spellingShingle | Jennifer Carlisle Michel Margaret M B Grivette Amber T Harshfield Lisa Huynh Ava P Komons Bradley Loomis Kaitlan McKinnis Brennen T Miller Ethan Q Nguyen Tiffany W Huang Sophia Lauf Elias S Michel Mia E Michel Jane S Kissinger Audrey J Marsh William E Crow Lila E Kaye Abagael M Lasseigne Rachel M Lukowicz-Bedford Dylan R Farnsworth E Anne Martin Adam C Miller Electrical synapse structure requires distinct isoforms of a postsynaptic scaffold. PLoS Genetics |
| title | Electrical synapse structure requires distinct isoforms of a postsynaptic scaffold. |
| title_full | Electrical synapse structure requires distinct isoforms of a postsynaptic scaffold. |
| title_fullStr | Electrical synapse structure requires distinct isoforms of a postsynaptic scaffold. |
| title_full_unstemmed | Electrical synapse structure requires distinct isoforms of a postsynaptic scaffold. |
| title_short | Electrical synapse structure requires distinct isoforms of a postsynaptic scaffold. |
| title_sort | electrical synapse structure requires distinct isoforms of a postsynaptic scaffold |
| url | https://journals.plos.org/plosgenetics/article/file?id=10.1371/journal.pgen.1011045&type=printable |
| work_keys_str_mv | AT jennifercarlislemichel electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT margaretmbgrivette electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT ambertharshfield electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT lisahuynh electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT avapkomons electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT bradleyloomis electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT kaitlanmckinnis electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT brennentmiller electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT ethanqnguyen electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT tiffanywhuang electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT sophialauf electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT eliassmichel electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT miaemichel electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT janeskissinger electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT audreyjmarsh electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT williamecrow electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT lilaekaye electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT abagaelmlasseigne electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT rachelmlukowiczbedford electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT dylanrfarnsworth electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT eannemartin electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold AT adamcmiller electricalsynapsestructurerequiresdistinctisoformsofapostsynapticscaffold |