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Cetin-Ferra S, Francis SC, Cooper AT, Neikirk K, Marshall AG, Hinton A, Murray SA. Mitochondrial Connexins and Mitochondrial Contact Sites with Gap Junction Structure. Int J Mol Sci 2023; 24:ijms24109036. [PMID: 37240383 DOI: 10.3390/ijms24109036] [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: 04/14/2023] [Revised: 05/16/2023] [Accepted: 05/16/2023] [Indexed: 05/28/2023] Open
Abstract
Mitochondria contain connexins, a family of proteins that is known to form gap junction channels. Connexins are synthesized in the endoplasmic reticulum and oligomerized in the Golgi to form hemichannels. Hemichannels from adjacent cells dock with one another to form gap junction channels that aggregate into plaques and allow cell-cell communication. Cell-cell communication was once thought to be the only function of connexins and their gap junction channels. In the mitochondria, however, connexins have been identified as monomers and assembled into hemichannels, thus questioning their role solely as cell-cell communication channels. Accordingly, mitochondrial connexins have been suggested to play critical roles in the regulation of mitochondrial functions, including potassium fluxes and respiration. However, while much is known about plasma membrane gap junction channel connexins, the presence and function of mitochondrial connexins remain poorly understood. In this review, the presence and role of mitochondrial connexins and mitochondrial/connexin-containing structure contact sites will be discussed. An understanding of the significance of mitochondrial connexins and their connexin contact sites is essential to our knowledge of connexins' functions in normal and pathological conditions, and this information may aid in the development of therapeutic interventions in diseases linked to mitochondria.
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Affiliation(s)
- Selma Cetin-Ferra
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Sharon C Francis
- Department of Physiology, Morehouse School of Medicine, Atlanta, GA 30310, USA
| | - Anthonya T Cooper
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
- Department of Biology, University of Hawaii, Hilo, HI 96720, USA
| | - Andrea G Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Sandra A Murray
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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2
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Ortiz J, Bobkov YV, DeBiasse MB, Mitchell DG, Edgar A, Martindale MQ, Moss AG, Babonis LS, Ryan JF. Independent Innexin Radiation Shaped Signaling in Ctenophores. Mol Biol Evol 2023; 40:7026321. [PMID: 36740225 PMCID: PMC9949713 DOI: 10.1093/molbev/msad025] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Revised: 12/30/2022] [Accepted: 01/25/2023] [Indexed: 02/07/2023] Open
Abstract
Innexins facilitate cell-cell communication by forming gap junctions or nonjunctional hemichannels, which play important roles in metabolic, chemical, ionic, and electrical coupling. The lack of knowledge regarding the evolution and role of these channels in ctenophores (comb jellies), the likely sister group to the rest of animals, represents a substantial gap in our understanding of the evolution of intercellular communication in animals. Here, we identify and phylogenetically characterize the complete set of innexins of four ctenophores: Mnemiopsis leidyi, Hormiphora californensis, Pleurobrachia bachei, and Beroe ovata. Our phylogenetic analyses suggest that ctenophore innexins diversified independently from those of other animals and were established early in the emergence of ctenophores. We identified a four-innexin genomic cluster, which was present in the last common ancestor of these four species and has been largely maintained in these lineages. Evidence from correlated spatial and temporal gene expression of the M. leidyi innexin cluster suggests that this cluster has been maintained due to constraints related to gene regulation. We describe the basic electrophysiological properties of putative ctenophore hemichannels from muscle cells using intracellular recording techniques, showing substantial overlap with the properties of bilaterian innexin channels. Together, our results suggest that the last common ancestor of animals had gap junctional channels also capable of forming functional innexin hemichannels, and that innexin genes have independently evolved in major lineages throughout Metazoa.
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Affiliation(s)
| | | | - Melissa B DeBiasse
- Whitney Laboratory for Marine Bioscience, University of Florida, St Augustine, FL, USA,School of Natural Sciences, University of California Merced, Merced, CA, USA
| | - Dorothy G Mitchell
- Whitney Laboratory for Marine Bioscience, University of Florida, St Augustine, FL, USA,Department of Biology, University of Florida, Gainesville, FL, USA
| | - Allison Edgar
- Whitney Laboratory for Marine Bioscience, University of Florida, St Augustine, FL, USA
| | - Mark Q Martindale
- Whitney Laboratory for Marine Bioscience, University of Florida, St Augustine, FL, USA,Department of Biology, University of Florida, Gainesville, FL, USA
| | - Anthony G Moss
- Biological Sciences Department, Auburn University, Auburn, AL, USA
| | - Leslie S Babonis
- Whitney Laboratory for Marine Bioscience, University of Florida, St Augustine, FL, USA,Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
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3
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Welzel G, Schuster S. Connexins evolved after early chordates lost innexin diversity. eLife 2022; 11:74422. [PMID: 35042580 PMCID: PMC8769644 DOI: 10.7554/elife.74422] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Accepted: 01/05/2022] [Indexed: 11/26/2022] Open
Abstract
Gap junction channels are formed by two unrelated protein families. Non-chordates use the primordial innexins, while chordates use connexins that superseded the gap junction function of innexins. Chordates retained innexin-homologs, but N-glycosylation prevents them from forming gap junctions. It is puzzling why chordates seem to exclusively use the new gap junction protein and why no chordates should exist that use non-glycosylated innexins to form gap junctions. Here, we identified glycosylation sites of 2388 innexins from 174 non-chordate and 276 chordate species. Among all chordates, we found not a single innexin without glycosylation sites. Surprisingly, the glycosylation motif is also widespread among non-chordate innexins indicating that glycosylated innexins are not a novelty of chordates. In addition, we discovered a loss of innexin diversity during early chordate evolution. Most importantly, lancelets, which lack connexins, exclusively possess only one highly conserved innexin with one glycosylation site. A bottleneck effect might thus explain why connexins have become the only protein used to form chordate gap junctions.
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Affiliation(s)
- Georg Welzel
- Department of Animal Physiology, University of Bayreuth
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Battulin N, Kovalzon VM, Korablev A, Serova I, Kiryukhina OO, Pechkova MG, Bogotskoy KA, Tarasova OS, Panchin Y. Pannexin 1 Transgenic Mice: Human Diseases and Sleep-Wake Function Revision. Int J Mol Sci 2021; 22:ijms22105269. [PMID: 34067798 PMCID: PMC8155943 DOI: 10.3390/ijms22105269] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/13/2021] [Accepted: 05/14/2021] [Indexed: 12/26/2022] Open
Abstract
In humans and other vertebrates pannexin protein family was discovered by homology to invertebrate gap junction proteins. Several biological functions were attributed to three vertebrate pannexins members. Six clinically significant independent variants of the PANX1 gene lead to human infertility and oocyte development defects, and the Arg217His variant was associated with pronounced symptoms of primary ovarian failure, severe intellectual disability, sensorineural hearing loss, and kyphosis. At the same time, only mild phenotypes were observed in Panx1 knockout mice. In addition, a passenger mutation was identified in a popular line of Panx1 knockout mice, questioning even those effects. Using CRISPR/Cas9, we created a new line of Panx1 knockout mice and a new line of mice with the clinically significant Panx1 substitution (Arg217His). In both cases, we observed no significant changes in mouse size, weight, or fertility. In addition, we attempted to reproduce a previous study on sleep/wake and locomotor activity functions in Panx1 knockout mice and found that previously reported effects were probably not caused by the Panx1 knockout itself. We consider that the pathological role of Arg217His substitution in Panx1, and some Panx1 functions in general calls for a re-evaluation.
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Affiliation(s)
- Nariman Battulin
- Laboratory of Developmental Genetics, Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia; (A.K.); (I.S.)
- Correspondence:
| | - Vladimir M. Kovalzon
- Laboratory of Mammal Behavior and Behavioral Ecology, Severtsov Institute Ecology and Evolution, Russian Academy of Sciences, 119071 Moscow, Russia;
- Laboratory for the Study of Information Processes at the Cellular and Molecular Levels, Institute for Information Transmission Problems, Russian Academy of Sciences, 119333 Moscow, Russia; (O.O.K.); (Y.P.)
| | - Alexey Korablev
- Laboratory of Developmental Genetics, Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia; (A.K.); (I.S.)
| | - Irina Serova
- Laboratory of Developmental Genetics, Institute of Cytology and Genetics SB RAS, 630090 Novosibirsk, Russia; (A.K.); (I.S.)
| | - Oxana O. Kiryukhina
- Laboratory for the Study of Information Processes at the Cellular and Molecular Levels, Institute for Information Transmission Problems, Russian Academy of Sciences, 119333 Moscow, Russia; (O.O.K.); (Y.P.)
- Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia; (M.G.P.); (K.A.B.); (O.S.T.)
| | - Marta G. Pechkova
- Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia; (M.G.P.); (K.A.B.); (O.S.T.)
| | - Kirill A. Bogotskoy
- Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia; (M.G.P.); (K.A.B.); (O.S.T.)
| | - Olga S. Tarasova
- Department of Human and Animal Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia; (M.G.P.); (K.A.B.); (O.S.T.)
| | - Yuri Panchin
- Laboratory for the Study of Information Processes at the Cellular and Molecular Levels, Institute for Information Transmission Problems, Russian Academy of Sciences, 119333 Moscow, Russia; (O.O.K.); (Y.P.)
- Department of Mathematical Methods in Biology, Belozersky Institute, M.V. Lomonosov Moscow State University, 119234 Moscow, Russia
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Moroz LL, Romanova DY, Kohn AB. Neural versus alternative integrative systems: molecular insights into origins of neurotransmitters. Philos Trans R Soc Lond B Biol Sci 2021; 376:20190762. [PMID: 33550949 PMCID: PMC7935107 DOI: 10.1098/rstb.2019.0762] [Citation(s) in RCA: 46] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Transmitter signalling is the universal chemical language of any nervous system, but little is known about its early evolution. Here, we summarize data about the distribution and functions of neurotransmitter systems in basal metazoans as well as outline hypotheses of their origins. We explore the scenario that neurons arose from genetically different populations of secretory cells capable of volume chemical transmission and integration of behaviours without canonical synapses. The closest representation of this primordial organization is currently found in Placozoa, disk-like animals with the simplest known cell composition but complex behaviours. We propose that injury-related signalling was the evolutionary predecessor for integrative functions of early transmitters such as nitric oxide, ATP, protons, glutamate and small peptides. By contrast, acetylcholine, dopamine, noradrenaline, octopamine, serotonin and histamine were recruited as canonical neurotransmitters relatively later in animal evolution, only in bilaterians. Ligand-gated ion channels often preceded the establishment of novel neurotransmitter systems. Moreover, lineage-specific diversification of neurotransmitter receptors occurred in parallel within Cnidaria and several bilaterian lineages, including acoels. In summary, ancestral diversification of secretory signal molecules provides unique chemical microenvironments for behaviour-driven innovations that pave the way to complex brain functions and elementary cognition. This article is part of the theme issue 'Basal cognition: multicellularity, neurons and the cognitive lens'.
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Affiliation(s)
- Leonid L. Moroz
- Department of Neuroscience, McKnight Brain Institute and Whitney laboratory, University of Florida, 9505 Ocean shore Blvd, St Augustine, FL 32080, USA
| | - Daria Y. Romanova
- Laboratory of Cellular Neurobiology of Learning, Institute of Higher Nervous Activity and Neurophysiology of RAS, 5A Butlerova Street, Moscow 117485, Russia
| | - Andrea B. Kohn
- Department of Neuroscience, McKnight Brain Institute and Whitney laboratory, University of Florida, 9505 Ocean shore Blvd, St Augustine, FL 32080, USA
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Katow H, Abe K, Katow T, Yoshida H, Kiyomoto M. Involvement of Netrin/Unc-5 Interaction in Ciliary Beating and in Pattern Formation of the Ciliary Band-Associated Strand (CBAS) in the Sea Urchin, Hemicentrotus pulcherrimus. Int J Mol Sci 2020; 21:E6587. [PMID: 32916859 PMCID: PMC7555569 DOI: 10.3390/ijms21186587] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/06/2020] [Accepted: 09/07/2020] [Indexed: 01/01/2023] Open
Abstract
The GABAergic neural circuit is involved in the motile activities of both larval and juvenile sea urchins. Therefore, its function is inherited beyond metamorphosis, despite large scale remodeling of larval organs during that period. However, the initial neural circuit formation mechanism is not well understood, including how glutamate decarboxylase-expressing blastocoelar cells (GADCs) construct the neural circuit along the circumoral ciliary band (a ciliary band-associated strand, CBAS) on the larval body surface. In this study, using whole-mount immunohistochemistry and 3D reconstructed imaging, the ontogenic process of CBAS patterning was studied by focusing on Netrin and the interaction with its receptor, Unc-5. During the early 2-arm pluteus stage, a small number of GADCs egress onto the apical surface of the larval ectoderm. Then, they line up on the circumoral side of the ciliary band, and by being inserted by a further number of GADCs, form longer multicellular strands along the Netrin stripe. Application of a synthetic peptide, CRFNMELYKLSGRKSGGVC of Hp-Netrin, that binds to the immunoglobulin domain of Unc-5 during the prism stage, causes stunted CBAS formation due to inhibition of GADC egression. This also results in reduced ciliary beating. Thus, the Netrin/Unc-5 interaction is involved in the construction and function of the CBAS.
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Affiliation(s)
- Hideki Katow
- Research Center for Marine Biology, Tohoku University, Asamushi, Aomori 039-3501, Japan; (K.A.); (T.K.)
- Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan; (H.Y.); (M.K.)
| | - Kouki Abe
- Research Center for Marine Biology, Tohoku University, Asamushi, Aomori 039-3501, Japan; (K.A.); (T.K.)
| | - Tomoko Katow
- Research Center for Marine Biology, Tohoku University, Asamushi, Aomori 039-3501, Japan; (K.A.); (T.K.)
| | - Hiromi Yoshida
- Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan; (H.Y.); (M.K.)
| | - Masato Kiyomoto
- Institute of Development, Aging and Cancer, Tohoku University, Sendai 980-8575, Japan; (H.Y.); (M.K.)
- Marine and Coastal Research Center, Ochanomizu University, Tateyama, Chiba 294-0301, Japan
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Martin EA, Lasseigne AM, Miller AC. Understanding the Molecular and Cell Biological Mechanisms of Electrical Synapse Formation. Front Neuroanat 2020; 14:12. [PMID: 32372919 PMCID: PMC7179694 DOI: 10.3389/fnana.2020.00012] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 03/09/2020] [Indexed: 12/20/2022] Open
Abstract
In this review article, we will describe the recent advances made towards understanding the molecular and cell biological mechanisms of electrical synapse formation. New evidence indicates that electrical synapses, which are gap junctions between neurons, can have complex molecular compositions including protein asymmetries across joined cells, diverse morphological arrangements, and overlooked similarities with other junctions, all of which indicate new potential roles in neurodevelopmental disease. Aquatic organisms, and in particular the vertebrate zebrafish, have proven to be excellent models for elucidating the molecular mechanisms of electrical synapse formation. Zebrafish will serve as our main exemplar throughout this review and will be compared with other model organisms. We highlight the known cell biological processes that build neuronal gap junctions and compare these with the assemblies of adherens junctions, tight junctions, non-neuronal gap junctions, and chemical synapses to explore the unknown frontiers remaining in our understanding of the critical and ubiquitous electrical synapse.
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Affiliation(s)
- E Anne Martin
- Department of Biology, Institute of Neuroscience, University of Oregon, Eugene, OR, United States
| | - Abagael M Lasseigne
- Department of Biology, Institute of Neuroscience, University of Oregon, Eugene, OR, United States
| | - Adam C Miller
- Department of Biology, Institute of Neuroscience, University of Oregon, Eugene, OR, United States
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8
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Wu X, Zhang W, Li Y, Lin X. Structure and Function of Cochlear Gap Junctions and Implications for the Translation of Cochlear Gene Therapies. Front Cell Neurosci 2019; 13:529. [PMID: 31827424 PMCID: PMC6892400 DOI: 10.3389/fncel.2019.00529] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 11/13/2019] [Indexed: 12/23/2022] Open
Abstract
Connexins (Cxs) are ubiquitous membrane proteins that are found throughout vertebrate organs, acting as building blocks of the gap junctions (GJs) known to play vital roles in the normal function of many organs. Mutations in Cx genes (particularly GJB2, which encodes Cx26) cause approximately half of all cases of congenital hearing loss in newborns. Great progress has been made in understanding GJ function and the molecular mechanisms for the role of Cxs in the cochlea. Data reveal that multiple types of Cxs work together to ensure normal development and function of the cochlea. These findings include many aspects not proposed in the classic K+ recycling theory, such as the formation of normal cochlear morphology (e.g., the opening of the tunnel of Corti), the fine-tuning of the innervation of nerve fibers to the hair cells (HCs), the maturation of the ribbon synapses, and the initiation of the endocochlear potential (EP). New data, especially those collected from targeted modification of major Cx genes in the mouse cochlea, have demonstrated that Cx26 plays an essential role in the postnatal maturation of the cochlea. Studies also show that Cx26 and Cx30 assume very different roles in the EP generation, given that only Cx26 is required for normal hearing. This article will review our current understanding of the molecular structure, cellular distribution, and major functions of cochlear GJs. Potential implications of the knowledge of cochlear GJs on the design and implementation of translational studies of cochlear gene therapies for Cx mutations are also discussed.
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Affiliation(s)
- Xuewen Wu
- Department of Otolaryngology, Head-Neck and Surgery, Xiangya Hospital of Central South University, Changsha, China
- Department of Otolaryngology, Emory University School of Medicine, Atlanta, GA, United States
| | - Wenjuan Zhang
- Department of Otolaryngology, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yihui Li
- Department of Pharmacy, Changsha Hospital of Traditional Medicine, Changsha, China
| | - Xi Lin
- Department of Otolaryngology, Emory University School of Medicine, Atlanta, GA, United States
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Orlov YL, Baranova AV, Kolchanov NA, Moroz LL. Evolutionary biology and biodiversity research at BGRS-2018. BMC Evol Biol 2019; 19:43. [PMID: 30813910 PMCID: PMC6391745 DOI: 10.1186/s12862-019-1368-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Affiliation(s)
- Yuriy L Orlov
- Institute of Cytology and Genetics SB RAS, 630090, Novosibirsk, Russia. .,Novosibirsk State University, 630090, Novosibirsk, Russia. .,The A.O.Kovalevsky Institute of Marine Biological Research of RAS, Moscow, Russia.
| | - Ancha V Baranova
- Research Centre for Medical Genetics, Moscow, 115478, Russia.,School of Systems Biology, George Mason University, Fairfax, VA, USA
| | - Nikolay A Kolchanov
- Institute of Cytology and Genetics SB RAS, 630090, Novosibirsk, Russia.,Novosibirsk State University, 630090, Novosibirsk, Russia
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