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Ptashnik A, LaMassa N, Mambetalieva A, Schnall E, Bucaro M, Phillips GR. Ubiquitination of the protocadherin-γA3 variable cytoplasmic domain modulates cell-cell interaction. Front Cell Dev Biol 2023; 11:1261048. [PMID: 37791076 PMCID: PMC10544333 DOI: 10.3389/fcell.2023.1261048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 09/04/2023] [Indexed: 10/05/2023] Open
Abstract
The family of ∼60 clustered protocadherins (Pcdhs) are cell adhesion molecules encoded by a genomic locus that regulates expression of distinct combinations of isoforms in individual neurons resulting in what is thought to be a neural surface "barcode" which mediates same-cell interactions of dendrites, as well as interactions with other cells in the environment. Pcdh mediated same-cell dendrite interactions were shown to result in avoidance while interactions between different cells through Pcdhs, such as between neurons and astrocytes, appear to be stable. The cell biological mechanism of the consequences of Pcdh based adhesion is not well understood although various signaling pathways have been recently uncovered. A still unidentified cytoplasmic regulatory mechanism might contribute to a "switch" between avoidance and adhesion. We have proposed that endocytosis and intracellular trafficking could be part of such a switch. Here we use "stub" constructs consisting of the proximal cytoplasmic domain (lacking the constant carboxy-terminal domain spliced to all Pcdh-γs) of one Pcdh, Pcdh-γA3, to study trafficking. We found that the stub construct traffics primarily to Rab7 positive endosomes very similarly to the full length molecule and deletion of a substantial portion of the carboxy-terminus of the stub eliminates this trafficking. The intact stub was found to be ubiquitinated while the deletion was not and this ubiquitination was found to be at non-lysine sites. Further deletion mapping of the residues required for ubiquitination identified potential serine phosphorylation sites, conserved among Pcdh-γAs, that can reduce ubiquitination when pseudophosphorylated and increase surface expression. These results suggest Pcdh-γA ubiquitination can influence surface expression which may modulate adhesive activity during neural development.
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Affiliation(s)
- Albert Ptashnik
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
- PhD Program in Biology, Subprogram in Neuroscience, CUNY Graduate Center, New York, NY, United States
| | - Nicole LaMassa
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
- PhD Program in Biology, Subprogram in Neuroscience, CUNY Graduate Center, New York, NY, United States
| | - Aliya Mambetalieva
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
| | - Emily Schnall
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
| | - Mike Bucaro
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
| | - Greg R. Phillips
- Department of Biology, College of Staten Island, City University of New York, New York, NY, United States
- PhD Program in Biology, Subprogram in Neuroscience, CUNY Graduate Center, New York, NY, United States
- Center for Developmental Neuroscience, College of Staten Island, City University of New York, New York, NY, United States
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2
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Swierkowska J, Karolak JA, Vishweswaraiah S, Mrugacz M, Radhakrishna U, Gajecka M. Decreased Levels of DNA Methylation in the PCDHA Gene Cluster as a Risk Factor for Early-Onset High Myopia in Young Children. Invest Ophthalmol Vis Sci 2022; 63:31. [PMID: 36036911 PMCID: PMC9434983 DOI: 10.1167/iovs.63.9.31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Purpose High myopia (HM), an eye disorder with at least –6.0 diopters refractive error, has a complex etiology with environmental, genetic, and likely epigenetic factors involved. To complement the DNA methylation assessment in children with HM, we analyzed genes that had significantly lower DNA methylation levels. Methods The DNA methylation pattern was studied based on the genome-wide methylation data of 18 Polish children with HM paired with 18 controls. Genes overlapping CG dinucleotides with decreased methylation level in HM cases were assessed by enrichment analyses. From those, genes with CG dinucleotides in promoter regions were further evaluated based on exome sequencing (ES) data of 16 patients with HM from unrelated Polish families, Sanger sequencing data of the studied children, and the RNA sequencing data of human retinal ARPE-19 cells. Results The CG dinucleotide with the most decreased methylation level in cases was identified in a promoter region of PCDHA10 that overlaps intronic regions of PCDHA1–9 of the PCDHA gene cluster in myopia 5q31 locus. Also, two single nucleotide variants, rs200661444, detected in our ES, and rs246073, previously found as associated with a refractive error in a genome-wide association study, were revealed within this gene cluster. Additionally, genes previously linked to ocular phenotypes, myopia-related traits, or loci, including ADAM20, ZFAND6, ETS1, ABHD13, SBSPON, SORBS2, LMOD3, ATXN1, and FARP2, were found to have decreased methylation. Conclusions Alterations in the methylation pattern of specific CG dinucleotides may be associated with early-onset HM, so this could be used to develop noninvasive biomarkers of HM in children and adolescents.
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Affiliation(s)
| | - Justyna A Karolak
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland.,Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
| | - Sangeetha Vishweswaraiah
- Department of Obstetrics and Gynecology, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan, United States
| | - Malgorzata Mrugacz
- Department of Ophthalmology and Eye Rehabilitation, Medical University of Bialystok, Bialystok, Poland
| | - Uppala Radhakrishna
- Department of Obstetrics and Gynecology, Oakland University William Beaumont School of Medicine, Royal Oak, Michigan, United States
| | - Marzena Gajecka
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland.,Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
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3
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Self-avoidance alone does not explain the function of Dscam1 in mushroom body axonal wiring. Curr Biol 2022; 32:2908-2920.e4. [PMID: 35659864 DOI: 10.1016/j.cub.2022.05.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/28/2022] [Accepted: 05/11/2022] [Indexed: 11/24/2022]
Abstract
Alternative splicing of Drosophila Dscam1 into 38,016 isoforms provides neurons with a unique molecular code for self-recognition and self-avoidance. A canonical model suggests that the homophilic binding of identical Dscam1 isoforms on the sister branches of mushroom body (MB) axons supports segregation with high fidelity, even when only a single isoform is expressed. Here, we generated a series of mutant flies with a single exon 4, 6, or 9 variant, encoding 1,584, 396, or 576 potential isoforms, respectively. Surprisingly, most of the mutants in the latter two groups exhibited obvious defects in the growth, branching, and segregation of MB axonal sister branches. This demonstrates that the repertoires of 396 and 576 Dscam1 isoforms were not sufficient for the normal patterning of axonal branches. Moreover, reducing Dscam1 levels largely reversed the defects caused by reduced isoform diversity, suggesting a functional link between Dscam1 expression levels and isoform diversity. Taken together, these results indicate that canonical self-avoidance alone does not explain the function of Dscam1 in MB axonal wiring.
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Xia D, Zhang X, Deng D, Ma X, Masri S, Wang J, Bao S, Hu S, Zhou Q. Long-Term Enhancement of NMDA Receptor Function in Inhibitory Neurons Preferentially Modulates Potassium Channels and Cell Adhesion Molecules. Front Pharmacol 2022; 12:796179. [PMID: 35058780 PMCID: PMC8764260 DOI: 10.3389/fphar.2021.796179] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Accepted: 11/22/2021] [Indexed: 12/31/2022] Open
Abstract
Effectively enhancing the activity of inhibitory neurons has great therapeutic potentials since their reduced function/activity has significant contributions to pathology in various brain diseases. We showed previously that NMDAR positive allosteric modulator GNE-8324 and M-8324 selectively increase NMDAR activity on the inhibitory neurons and elevates their activity in vitro and in vivo. Here we examined the impact of long-term administering M-8324 on the functions and transcriptional profiling of parvalbumin-containing neurons in two representative brain regions, primary auditory cortex (Au1) and prelimbic prefrontal cortex (PrL-PFC). We found small changes in key electrophysiological parameters and RNA levels of neurotransmitter receptors, Na+ and Ca2+ channels. In contrast, large differences in cell adhesion molecules and K+ channels were found between Au1 and PrL-PFC in drug-naïve mice, and differences in cell adhesion molecules became much smaller after M-8324 treatment. There was also minor impact of M-8324 on cell cycle and apoptosis, suggesting a fine safety profile.
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Affiliation(s)
- Dan Xia
- State Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Xinyang Zhang
- State Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Di Deng
- State Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China.,International Institute for Translational Chinese Medicine, School of Pharmaceutical Sciences, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xiaoyan Ma
- State Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Samer Masri
- Department of Physiology, University of Arizona, Tucson, AZ, United States
| | - Jianzheng Wang
- State Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
| | - Shaowen Bao
- Department of Physiology, University of Arizona, Tucson, AZ, United States
| | - Songnian Hu
- CAS Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Qiang Zhou
- State Key Laboratory of Chemical Oncogenomics, Guangdong Provincial Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen, China
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5
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Gallerani N, Au E. Loss of Clustered Protocadherin Diversity Alters the Spatial Distribution of Cortical Interneurons in Mice. Cereb Cortex Commun 2020; 1:tgaa089. [PMID: 34296145 PMCID: PMC8152951 DOI: 10.1093/texcom/tgaa089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 11/13/2020] [Accepted: 11/19/2020] [Indexed: 11/13/2022] Open
Abstract
Cortical interneurons (cINs) are locally projecting inhibitory neurons that are distributed throughout the cortex. Due to their relatively limited range of influence, their arrangement in the cortex is critical to their function. cINs achieve this arrangement through a process of tangential and radial migration and apoptosis during development. In this study, we investigated the role of clustered protocadherins (cPcdhs) in establishing the spatial patterning of cINs through the use of genetic cPcdh knockout mice. cPcdhs are expressed in cINs and are known to play key functions in cell spacing and cell survival, but their role in cINs is poorly understood. Using spatial statistical analysis, we found that the 2 main subclasses of cINs, parvalbumin-expressing and somatostatin-expressing (SST) cINs, are nonrandomly spaced within subclass but randomly with respect to each other. We also found that the relative laminar distribution of each subclass was distinctly altered in whole α- or β-cluster mutants. Examination of perinatal time points revealed that the mutant phenotypes emerged relatively late, suggesting that cPcdhs may be acting during cIN morphological elaboration and synaptogenesis. We then analyzed an isoform-specific knockout for pcdh-αc2 and found that it recapitulated the α-cluster knockout but only in SST cells, suggesting that subtype-specific expression of cPcdh isoforms may help govern subtype-specific spatial distribution.
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Affiliation(s)
- Nicholas Gallerani
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Edmund Au
- Department of Pathology & Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA.,Department of Rehabilitative Medicine and Regeneration, Columbia University Irving Medical Center, New York, NY 10032, USA.,Columbia University Irving Medical Center, New York NY, 10032, USA
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Maternal immune activation alters visual acuity and retinogeniculate axon pruning in offspring mice. Brain Behav Immun 2020; 89:518-523. [PMID: 32827701 DOI: 10.1016/j.bbi.2020.08.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 08/16/2020] [Accepted: 08/17/2020] [Indexed: 01/29/2023] Open
Abstract
Individuals with autism spectrum disorder (ASD) have been found to have a variety of sensory processing deficits. Here we report that maternal immune activation, a known factor for ASD, alters visual acuity in the offspring mice. By intraperitoneally injecting polyinosinic-polycytidylic acid (polyI:C) to induce maternal immune activation during embryonic days 10 to 14, we found that polyI:C treatment impairs visual acuity in young adult offspring mice as examined by their optomotor responses. Concurrently, polyI:C treatment suppresses retinogeniculate axon elimination, resulting in a high fraction of weak optical fibers innervating the relay neurons in the visual thalamus. The results link in-utero maternal inflammation to defective optical fiber pruning and arrested developmental strengthening of single optic fibers which may underlie impaired visual acuity.
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7
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Sanes JR, Zipursky SL. Synaptic Specificity, Recognition Molecules, and Assembly of Neural Circuits. Cell 2020; 181:536-556. [DOI: 10.1016/j.cell.2020.04.008] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 03/23/2020] [Accepted: 04/06/2020] [Indexed: 01/02/2023]
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8
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Garrett AM, Bosch PJ, Steffen DM, Fuller LC, Marcucci CG, Koch AA, Bais P, Weiner JA, Burgess RW. CRISPR/Cas9 interrogation of the mouse Pcdhg gene cluster reveals a crucial isoform-specific role for Pcdhgc4. PLoS Genet 2019; 15:e1008554. [PMID: 31877124 PMCID: PMC6957209 DOI: 10.1371/journal.pgen.1008554] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 01/13/2020] [Accepted: 12/05/2019] [Indexed: 12/18/2022] Open
Abstract
The mammalian Pcdhg gene cluster encodes a family of 22 cell adhesion molecules, the gamma-Protocadherins (γ-Pcdhs), critical for neuronal survival and neural circuit formation. The extent to which isoform diversity–a γ-Pcdh hallmark–is required for their functions remains unclear. We used a CRISPR/Cas9 approach to reduce isoform diversity, targeting each Pcdhg variable exon with pooled sgRNAs to generate an allelic series of 26 mouse lines with 1 to 21 isoforms disrupted via discrete indels at guide sites and/or larger deletions/rearrangements. Analysis of 5 mutant lines indicates that postnatal viability and neuronal survival do not require isoform diversity. Surprisingly, given reports that it might not independently engage in trans-interactions, we find that γC4, encoded by Pcdhgc4, is the only critical isoform. Because the human orthologue is the only PCDHG gene constrained in humans, our results indicate a conserved γC4 function that likely involves distinct molecular mechanisms. The γ-Protocadherins (γ-Pcdhs) are a family of 22 molecules that serve many crucial functions during neural development. They can combine to form multimers at the cell surface, such that each combination specifically recognizes the same combination at the surface of other cells. In this way, 22 molecules can generate thousands of distinct recognition complexes. To test the extent to which molecular diversity is required for the γ-Pcdhs to serve their many functions, we used CRISPR/Cas9 gene editing to make a series of mouse mutants in which different combinations of the γ-Pcdhs are disrupted. We report 25 new mouse lines with between 1 and 21 intact members of the γ-Pcdh family. Further, we found that for the critical function of neuronal survival–and consequently the survival of the animal–the molecular diversity was not essential. Rather, a single member of the family called γC4 was the only one necessary or sufficient for this function; databases of human genome sequences suggest that this important role is conserved. These new strains will be invaluable for disentangling the role of molecular diversity in the γ-Pcdhs’ functions, and as we have already found, will help identify specific functions for specific γ-Pcdh family members.
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Affiliation(s)
- Andrew M. Garrett
- Department of Pharmacology and Department of Ophthalmology, Visual, and Anatomical Sciences, Wayne State University, Detroit, Michigan, United States of America
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- * E-mail: (AMG); (JAW); (RWB)
| | - Peter J. Bosch
- Department of Biology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa, United States of America
| | - David M. Steffen
- Department of Biology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa, United States of America
| | - Leah C. Fuller
- Department of Biology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa, United States of America
| | - Charles G. Marcucci
- Department of Biology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa, United States of America
| | - Alexis A. Koch
- Department of Pharmacology and Department of Ophthalmology, Visual, and Anatomical Sciences, Wayne State University, Detroit, Michigan, United States of America
| | - Preeti Bais
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
| | - Joshua A. Weiner
- Department of Biology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa, United States of America
- * E-mail: (AMG); (JAW); (RWB)
| | - Robert W. Burgess
- The Jackson Laboratory, Bar Harbor, Maine, United States of America
- * E-mail: (AMG); (JAW); (RWB)
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Molecular diversity of clustered protocadherin-α required for sensory integration and short-term memory in mice. Sci Rep 2018; 8:9616. [PMID: 29941942 PMCID: PMC6018629 DOI: 10.1038/s41598-018-28034-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 06/14/2018] [Indexed: 12/11/2022] Open
Abstract
Clustered protocadherins (Pcdhs) are neuronal cell adhesion molecules characterized by homophilic adhesion between the tetramers of 58 distinct isoforms in mice. The diversity of Pcdhs and resulting highly-specific neuronal adhesion may be required for the formation of neural circuits for executing higher brain functions. However, this hypothesis remains to be tested, because knockout of Pcdh genes produces abnormalities that may interfere with higher brain functions indirectly. In Pcdh-α1,12 mice, only α1, α12 and two constitutive isoforms are expressed out of 14 isoforms. The appearance and behavior of Pcdh-α1,12 mice are similar to those of wild-type mice, and most abnormalities reported in Pcdh-α knockout mice are not present in Pcdh-α1,12 mice. We examined Pcdh-α1,12 mice in detail, and found that cortical depression induced by sensory mismatches between vision and whisker sensation in the visual cortex was impaired. Since Pcdh-α is densely distributed over the cerebral cortex, various types of higher function are likely impaired in Pcdh-α1,12 mice. As expected, visual short-term memory of space/shape was impaired in behavioral experiments using space/shape cues. Furthermore, behavioral learning based on audio-visual associative memory was also impaired. These results indicate that the molecular diversity of Pcdh-α plays essential roles for sensory integration and short-term memory.
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10
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Combinatorial Effects of Alpha- and Gamma-Protocadherins on Neuronal Survival and Dendritic Self-Avoidance. J Neurosci 2018; 38:2713-2729. [PMID: 29439167 DOI: 10.1523/jneurosci.3035-17.2018] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 01/12/2018] [Accepted: 01/29/2018] [Indexed: 12/16/2022] Open
Abstract
The clustered protocadherins (Pcdhs) comprise 58 cadherin-related proteins encoded by three tandemly arrayed gene clusters, Pcdh-α, Pcdh-β, and Pcdh-γ (Pcdha, Pcdhb, and Pcdhg, respectively). Pcdh isoforms from different clusters are combinatorially expressed in neurons. They form multimers that interact homophilically and mediate a variety of developmental processes, including neuronal survival, synaptic maintenance, axonal tiling, and dendritic self-avoidance. Most studies have analyzed clusters individually. Here, we assessed functional interactions between Pcdha and Pcdhg clusters. To circumvent neonatal lethality associated with deletion of Pcdhgs, we used Crispr-Cas9 genome editing in mice to combine a constitutive Pcdha mutant allele with a conditional Pcdhg allele. We analyzed roles of Pcdhas and Pcdhgs in the retina and cerebellum from mice (both sexes) lacking one or both clusters. In retina, Pcdhgs are essential for survival of inner retinal neurons and dendritic self-avoidance of starburst amacrine cells, whereas Pcdhas are dispensable for both processes. Deletion of both Pcdha and Pcdhg clusters led to far more dramatic defects in survival and self-avoidance than Pcdhg deletion alone. Comparisons of an allelic series of mutants support the conclusion that Pcdhas and Pcdhgs function together in a dose-dependent and cell-type-specific manner to provide a critical threshold of Pcdh activity. In the cerebellum, Pcdhas and Pcdhgs also cooperate to mediate self-avoidance of Purkinje cell dendrites, with modest but significant defects in either single mutant and dramatic defects in the double mutant. Together, our results demonstrate complex patterns of redundancy between Pcdh clusters and the importance of Pcdh cluster diversity in postnatal CNS development.SIGNIFICANCE STATEMENT The formation of neural circuits requires diversification and combinatorial actions of cell surface proteins. Prominent among them are the clustered protocadherins (Pcdhs), a family of ∼60 neuronal recognition molecules. Pcdhs are encoded by three closely linked gene clusters called Pcdh-α, Pcdh-β, and Pcdh-γ. The Pcdhs mediate a variety of developmental processes, including neuronal survival, synaptic maintenance, and spatial patterning of axons and dendrites. Most studies to date have been limited to single clusters. Here, we used genome editing to assess interactions between Pcdh-α and Pcdh-γ gene clusters. We examined two regions of the CNS, the retina and cerebellum and show that the 14 α-Pcdhs and 22 γ-Pcdhs act synergistically to mediate neuronal survival and dendrite patterning.
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Peek SL, Mah KM, Weiner JA. Regulation of neural circuit formation by protocadherins. Cell Mol Life Sci 2017; 74:4133-4157. [PMID: 28631008 PMCID: PMC5643215 DOI: 10.1007/s00018-017-2572-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 06/01/2017] [Accepted: 06/13/2017] [Indexed: 12/20/2022]
Abstract
The protocadherins (Pcdhs), which make up the most diverse group within the cadherin superfamily, were first discovered in the early 1990s. Data implicating the Pcdhs, including ~60 proteins encoded by the tandem Pcdha, Pcdhb, and Pcdhg gene clusters and another ~10 non-clustered Pcdhs, in the regulation of neural development have continually accumulated, with a significant expansion of the field over the past decade. Here, we review the many roles played by clustered and non-clustered Pcdhs in multiple steps important for the formation and function of neural circuits, including dendrite arborization, axon outgrowth and targeting, synaptogenesis, and synapse elimination. We further discuss studies implicating mutation or epigenetic dysregulation of Pcdh genes in a variety of human neurodevelopmental and neurological disorders. With recent structural modeling of Pcdh proteins, the prospects for uncovering molecular mechanisms of Pcdh extracellular and intracellular interactions, and their role in normal and disrupted neural circuit formation, are bright.
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Affiliation(s)
- Stacey L Peek
- Interdisciplinary Graduate Program in Neuroscience, The University of Iowa, Iowa City, IA, USA
- Department of Biology, The University of Iowa, Iowa City, IA, USA
| | - Kar Men Mah
- Department of Biology, The University of Iowa, Iowa City, IA, USA
| | - Joshua A Weiner
- Department of Biology, The University of Iowa, Iowa City, IA, USA.
- Department of Psychiatry, The University of Iowa, 143 Biology Building, Iowa City, IA, 52242, USA.
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12
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Abstract
Clustered protocadherins (Pcdhs) mediate numerous neural patterning functions, including neuronal self-recognition and non-self-discrimination to direct self-avoidance among vertebrate neurons. Individual neurons stochastically express a subset of Pcdh isoforms, which assemble to form a stochastic repertoire of cis-dimers. We describe the structure of a PcdhγB7 cis-homodimer, which includes the membrane-proximal extracellular cadherin domains EC5 and EC6. The structure is asymmetric with one molecule contributing interface surface from both EC5 and EC6, and the other only from EC6. Structural and sequence analyses suggest that all Pcdh isoforms will dimerize through this interface. Site-directed mutants at this interface interfere with both Pcdh cis-dimerization and cell surface transport. The structure explains the known restrictions of cis-interactions of some Pcdh isoforms, including α-Pcdhs, which cannot form homodimers. The asymmetry of the interface approximately doubles the size of the recognition repertoire, and restrictions on cis-interactions among Pcdh isoforms define the limits of the Pcdh recognition unit repertoire.
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13
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Mah KM, Weiner JA. Regulation of Wnt signaling by protocadherins. Semin Cell Dev Biol 2017; 69:158-171. [PMID: 28774578 PMCID: PMC5586504 DOI: 10.1016/j.semcdb.2017.07.043] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2017] [Revised: 07/21/2017] [Accepted: 07/28/2017] [Indexed: 12/23/2022]
Abstract
The ∼70 protocadherins comprise the largest group within the cadherin superfamily. Their diversity, the complexity of the mechanisms through which their genes are regulated, and their many critical functions in nervous system development have engendered a growing interest in elucidating the intracellular signaling pathways through which they act. Recently, multiple protocadherins across several subfamilies have been implicated as modulators of Wnt signaling pathways, and through this as potential tumor suppressors. Here, we review the extant data on the regulation by protocadherins of Wnt signaling pathways and components, and highlight some key unanswered questions that could shape future research.
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Affiliation(s)
- Kar Men Mah
- Department of Biology, The University of Iowa, Iowa City, IA, USA.
| | - Joshua A Weiner
- Department of Biology, The University of Iowa, Iowa City, IA, USA; Department of Psychiatry, The University of Iowa, Iowa City, IA, USA; Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, USA.
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14
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Hirayama T, Yagi T. Regulation of clustered protocadherin genes in individual neurons. Semin Cell Dev Biol 2017; 69:122-130. [PMID: 28591566 DOI: 10.1016/j.semcdb.2017.05.026] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 05/16/2017] [Accepted: 05/17/2017] [Indexed: 02/06/2023]
Abstract
Individual neurons are basic functional units in the complex system of the brain. One aspect of neuronal individuality is generated by stochastic and combinatorial expression of diverse clustered protocadherins (Pcdhs), encoded by the Pcdha, Pcdhb, and Pcdhg gene clusters, that are critical for several aspects of neural circuit formation. Each clustered Pcdh gene has its own promoter containing conserved sequences and is transcribed by a promoter choice mechanism involving interaction between the promoter and enhancers. A CTCF/Cohesin complex induces this interaction by configuration of DNA-looping in the chromatin structure. At the same time, the semi-stochastic expression of clustered Pcdh genes is regulated in individual neurons by DNA methylation: the methyltransferase Dnmt3b regulates methylation state of individual clustered Pcdh genes during early embryonic stages prior to the establishment of neural stem cells. Several other factors, including Smchd1, also contribute to the regulation of clustered Pcdh gene expression. In addition, psychiatric diseases and early life experiences of individuals can influence expression of clustered Pcdh genes in the brain, through epigenetic alterations. Clustered Pcdh gene expression is thus a significant and highly regulated step in establishing neuronal individuality and generating functional neural circuits in the brain.
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Affiliation(s)
- Teruyoshi Hirayama
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takeshi Yagi
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan.
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15
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Chen WV, Nwakeze CL, Denny CA, O'Keeffe S, Rieger MA, Mountoufaris G, Kirner A, Dougherty JD, Hen R, Wu Q, Maniatis T. Pcdhαc2 is required for axonal tiling and assembly of serotonergic circuitries in mice. Science 2017; 356:406-411. [PMID: 28450636 PMCID: PMC5529183 DOI: 10.1126/science.aal3231] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 02/21/2017] [Indexed: 12/19/2022]
Abstract
Serotonergic neurons project their axons pervasively throughout the brain and innervate various target fields in a space-filling manner, leading to tiled arrangements of their axon terminals to allow optimal allocation of serotonin among target neurons. Here we show that conditional deletion of the mouse protocadherin α (Pcdhα) gene cluster in serotonergic neurons disrupts local axonal tiling and global assembly of serotonergic circuitries and results in depression-like behaviors. Genetic dissection and expression profiling revealed that this role is specifically mediated by Pcdhαc2, which is the only Pcdhα isoform expressed in serotonergic neurons. We conclude that, in contrast to neurite self-avoidance, which requires single-cell identity mediated by Pcdh diversity, a single cell-type identity mediated by the common C-type Pcdh isoform is required for axonal tiling and assembly of serotonergic circuitries.
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Affiliation(s)
- Weisheng V Chen
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Chiamaka L Nwakeze
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Christine A Denny
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Integrative Neuroscience, Research Foundation for Mental Hygiene, New York, NY 10032, USA
| | - Sean O'Keeffe
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Michael A Rieger
- Departments of Genetics and Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - George Mountoufaris
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Amy Kirner
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Joseph D Dougherty
- Departments of Genetics and Psychiatry, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - René Hen
- Department of Psychiatry, Columbia University, New York, NY 10032, USA
- Division of Integrative Neuroscience, Research Foundation for Mental Hygiene, New York, NY 10032, USA
- Departments of Neuroscience and Pharmacology, Columbia University, New York, NY 10032, USA
| | - Qiang Wu
- Center for Comparative Biomedicine, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Tom Maniatis
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA.
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
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16
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Hasegawa S, Kumagai M, Hagihara M, Nishimaru H, Hirano K, Kaneko R, Okayama A, Hirayama T, Sanbo M, Hirabayashi M, Watanabe M, Hirabayashi T, Yagi T. Distinct and Cooperative Functions for the Protocadherin-α, -β and -γ Clusters in Neuronal Survival and Axon Targeting. Front Mol Neurosci 2016; 9:155. [PMID: 28066179 PMCID: PMC5179546 DOI: 10.3389/fnmol.2016.00155] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 12/07/2016] [Indexed: 01/29/2023] Open
Abstract
The clustered protocadherin (Pcdh) genes are divided into the Pcdhα, Pcdhβ, and Pcdhγ clusters. Gene-disruption analyses in mice have revealed the in vivo functions of the Pcdhα and Pcdhγ clusters. However, all Pcdh protein isoforms form combinatorial cis-hetero dimers and enter trans-homophilic interactions. Here we addressed distinct and cooperative functions in the Pcdh clusters by generating six cluster-deletion mutants (Δα, Δβ, Δγ, Δαβ, Δβγ, and Δαβγ) and comparing their phenotypes: Δα, Δβ, and Δαβ mutants were viable and fertile; Δγ mutants lived less than 12 h; and Δβγ and Δαβγ mutants died shortly after birth. The Pcdhα, Pcdhβ, and Pcdhγ clusters were individually and cooperatively important in olfactory-axon targeting and spinal-cord neuron survival. Neurodegeneration was most severe in Δαβγ mutants, indicating that Pcdhα and Pcdhβ function cooperatively for neuronal survival. The Pcdhα, Pcdhβ, and Pcdhγ clusters share roles in olfactory-axon targeting and neuronal survival, although to different degrees.
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Affiliation(s)
- Sonoko Hasegawa
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka UniversitySuita, Japan; AMED-CREST, Japan Agency for Medical Research and Development (AMED)Suita, Japan
| | - Makiko Kumagai
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka UniversitySuita, Japan; AMED-CREST, Japan Agency for Medical Research and Development (AMED)Suita, Japan
| | - Mitsue Hagihara
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka UniversitySuita, Japan; AMED-CREST, Japan Agency for Medical Research and Development (AMED)Suita, Japan
| | - Hiroshi Nishimaru
- Division of Biomedical Science, Faculty of Medicine, University of Tsukuba Tsukuba, Japan
| | - Keizo Hirano
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University Suita, Japan
| | - Ryosuke Kaneko
- Bioresource Center, Graduate School of Medicine, Gunma University Maebashi, Japan
| | - Atsushi Okayama
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka University Suita, Japan
| | - Teruyoshi Hirayama
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka UniversitySuita, Japan; AMED-CREST, Japan Agency for Medical Research and Development (AMED)Suita, Japan
| | - Makoto Sanbo
- Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological Sciences Okazaki, Japan
| | - Masumi Hirabayashi
- AMED-CREST, Japan Agency for Medical Research and Development (AMED)Suita, Japan; Section of Mammalian Transgenesis, Center for Genetic Analysis of Behavior, National Institute for Physiological SciencesOkazaki, Japan
| | - Masahiko Watanabe
- Department of Anatomy, Hokkaido University Graduate School of Medicine Sapporo, Japan
| | - Takahiro Hirabayashi
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka UniversitySuita, Japan; AMED-CREST, Japan Agency for Medical Research and Development (AMED)Suita, Japan
| | - Takeshi Yagi
- KOKORO-Biology Group, Laboratories for Integrated Biology, Graduate School of Frontier Biosciences, Osaka UniversitySuita, Japan; AMED-CREST, Japan Agency for Medical Research and Development (AMED)Suita, Japan
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17
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Mah KM, Houston DW, Weiner JA. The γ-Protocadherin-C3 isoform inhibits canonical Wnt signalling by binding to and stabilizing Axin1 at the membrane. Sci Rep 2016; 6:31665. [PMID: 27530555 PMCID: PMC4987702 DOI: 10.1038/srep31665] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 07/21/2016] [Indexed: 01/14/2023] Open
Abstract
The 22 γ-Protocadherin (γ-Pcdh) adhesion molecules encoded by the Pcdhg gene cluster play critical roles in nervous system development, including regulation of dendrite arborisation, neuronal survival, and synaptogenesis. Recently, they have been implicated in suppression of tumour cell growth by inhibition of canonical Wnt signalling, though the mechanisms through which this occurs remain unknown. Here, we show differential regulation of Wnt signalling by individual γ-Pcdhs: The C3 isoform uniquely inhibits the pathway, whilst 13 other isoforms upregulate signalling. Focusing on the C3 isoform, we show that its unique variable cytoplasmic domain (VCD) is the critical one for Wnt pathway inhibition. γ-Pcdh-C3, but not other isoforms, physically interacts with Axin1, a key component of the canonical Wnt pathway. The C3 VCD competes with Dishevelled for binding to the DIX domain of Axin1, which stabilizes Axin1 at the membrane and leads to reduced phosphorylation of Wnt co-receptor Lrp6. Finally, we present evidence that Wnt pathway activity can be modulated up (by γ-Pcdh-A1) or down (by γ-Pcdh-C3) in the cerebral cortex in vivo, using conditional transgenic alleles. Together, these data delineate opposing roles for γ-Pcdh isoforms in regulating Wnt signalling and identify Axin1 as a novel protein interactor of the widely-expressed γ-Pcdh-C3 isoform.
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Affiliation(s)
- Kar Men Mah
- Department of Biology, The University of Iowa, 143 Biology Building, Iowa City, 52242, IA, USA.,Integrated Biology Graduate Program, The University of Iowa, 143 Biology Building, Iowa City,52242, IA, USA
| | - Douglas W Houston
- Department of Biology, The University of Iowa, 143 Biology Building, Iowa City, 52242, IA, USA
| | - Joshua A Weiner
- Department of Biology, The University of Iowa, 143 Biology Building, Iowa City, 52242, IA, USA.,Department of Psychiatry, University of Iowa Carver College of Medicine, 200 Hawkins Drive, Iowa City, 52242, IA, USA
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18
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Kubota Y, Kondo S, Nomura M, Hatada S, Yamaguchi N, Mohamed AA, Karube F, Lübke J, Kawaguchi Y. Functional effects of distinct innervation styles of pyramidal cells by fast spiking cortical interneurons. eLife 2015; 4. [PMID: 26142457 PMCID: PMC4518632 DOI: 10.7554/elife.07919] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 07/04/2015] [Indexed: 01/16/2023] Open
Abstract
Inhibitory interneurons target precise membrane regions on pyramidal cells, but differences in their functional effects on somata, dendrites and spines remain unclear. We analyzed inhibitory synaptic events induced by cortical, fast-spiking (FS) basket cells which innervate dendritic shafts and spines as well as pyramidal cell somata. Serial electron micrograph (EMg) reconstructions showed that somatic synapses were larger than dendritic contacts. Simulations with precise anatomical and physiological data reveal functional differences between different innervation styles. FS cell soma-targeting synapses initiate a strong, global inhibition, those on shafts inhibit more restricted dendritic zones, while synapses on spines may mediate a strictly local veto. Thus, FS cell synapses of different sizes and sites provide functionally diverse forms of pyramidal cell inhibition.
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Affiliation(s)
- Yoshiyuki Kubota
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
| | - Satoru Kondo
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo, Japan
| | - Masaki Nomura
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo, Japan
| | - Sayuri Hatada
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
| | - Noboru Yamaguchi
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
| | - Alsayed A Mohamed
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
| | - Fuyuki Karube
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
| | - Joachim Lübke
- Institute of Neuroscience and Medicine, Research Centre Jülich, Jülich, Germany
| | - Yasuo Kawaguchi
- Division of Cerebral Circuitry, National Institute for Physiological Sciences, Okazaki, Japan
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