Rare missense variants of the leukocyte common antigen related receptor (LAR) display reduced activity in transcellular adhesion and synapse formation

Rare missense variants of the leukocyte common antigen related receptor (LAR) display reduced activity in transcellular adhesion and synapse formation | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Rare missense variants of the leukocyte common antigen related receptor (LAR) display reduced activity in transcellular adhesion and synapse formation Mathias Ollendorff, Nicolas Chofflet, Deniz Bicer, Jinjie Duan, and 17 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5928514/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract The leukocyte common antigen related receptor (LAR) is a member of the LAR receptor protein tyrosine phosphatase (RPTP) family of synaptic adhesion molecules that contribute to the proper alignment and specialization of synaptic connections in the mammalian brain. LAR-RPTP members have been genetically associated with neuropsychiatric disorders, but the molecular consequences of genetic perturbations of LAR remain unstudied. Using exome sequencing data from psychiatric patients and controls, we identify rare missense variants of LAR that render the extracellular domain (ECD) unstable and susceptible to proteolytic cleavage. Using recombinant and cellular systems, we describe three variants that cause disruption of the LAR:NGL-3 interaction, which results in loss of transcellular adhesion and synaptogenic effects. Furthermore, we show that overexpression of two of these variants elicit altered morphological phenotypes in an imaging-based morphological profiling assay compared to wild type LAR, suggesting that destabilization of the LAR ECD has broad effects on LAR function. In conclusion, our study identifies three rare, missense variants in LAR that could provide insights into LAR involvement with psychiatric pathobiology. Biological sciences/Neuroscience Health sciences/Diseases/Psychiatric disorders/ADHD Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Full Text Additional Declarations Yes ADB has received speaker fee from Lundbeck. The remaining authors declare no conflicts of interest. Supplementary Files 250129LARSuppl.pdf Supplemental Figure 1: Western blots of all rare missense variants identified in the iPSYCH cohort in transfected CHO-K1 cells. Blots were developed with a polyclonal antibody against the extracellular domain of LAR. Media were also analyzed for receptor shedding. A GAPDH antibody was used to show that cell viability was comparable between transfected cells. Of note, P416S was analyzed with a new plasmid prep and looked like WT LAR (data not shown). GAPDH indicated with asterisks are from a different blot with the same samples, but the mock and WT lanes were switched. The last blot illustrates the described non-rare variants identified. Supplemental Figure 2: a-c) Side chain positions for V389 (a), P417L (b) and P381 (c) are indicated in red with intermolecular sidechains within 4 Å shown as grey sticks (from experimental structure 6TPV of LAR FN1-2 [40]). d) Thermostability assessment using Tycho for remaining tested variants in this assay (n=2 pr variant) e) Fluorescent changes from SYPRO Orange ThermoFluor assay showing increases in normalized SYPRO Orange fluorescence during protein unfolding for remaining tested variants (n=3 pr variant, n=3 pr batch WT, 9 replicates in total). f) LAR WT vs. NGL-3 with observed changes in F-norm and KD assessment. g) Table showing changes in KD observed for the different variants. Supplemental Figure 3: a) Representative images of the remaining variants tested in transcellular adhesion assay. b) Quantification of remaining variants from the assay. No variants were significantly different (Kruskal Wallis test). Bar coloring indicates case-control status (control variants: white, shared variants: light grey, case variants: dark grey). Supplemental Figure 4: a) Quantitative assessment of LAR variant surface expression in HEK293 cells in the artificial synapse formation assay. Of note, cells were selected based on their similar expression for uniform PSD-95 analysis. None of the tested variants had significantly different levels at the cell surface in this assay (Kruskal Wallis test). Data are presented as mean ± SD. b) Representative images from SALM5-Fc surface binding to LAR meA-i-meB variants in transfected HEK293 cells. The scale bar represents 30 μm. c) Quantification of SALM5-Fc surface binding to LAR meA-i-meB variants in transfected HEK293 cells. Among the missense variants, only P417L showed significantly decreased SALM5 binding (p=0.0007, Kruskal Wallis test). Data are presented as mean ± SD. d) Surface expression of the same LAR variants as in c). Only P417L showed significant changes from WT (p=0.0052, Kruskal Wallis test). Data are presented as mean ± SD. Bar coloring indicates case-control status (control variants: white, case variants: dark grey). Supplemental Figure 5: a) SAXS data plotted at log-log scale of LAR wild-type and rare variants. Y-axis depicts the scattering intensity, I(q), and x-axis shows the momentum transfer vector, q. b-e) SAXS data points that are used for Guinier analysis and their normalized residual plots. Points that are on the red lines are used to calculate Rg (Å). Very low angle scattering points are neglected due to parasitic scattering and aggregation artefacts. Supplemental Figure 6: a-b) Additional model structure illustrations from AlphaFold2 and HDOCK modelling of the LAR FN1-4:NGL-3 interface. c) Predicted aligned error (PAE) plots of the three best AlphaFold2 models demonstrating high confidence in the interposition of the LRR domain of NGL-3 and the FN1 domain of LAR. The color code indicates the expected distance error in Ångströms (Å). Supplemental Figure 7: a-c) Pairwise comparison of LAR WT and missense variants as indicated. Dot size is scaled dependent on the p-value as illustrated. Data is from n=5-6 wells with a minimum of 20 LAR-positive cells pr well. Supplementarytable1.xlsx Supplementary Table 1: List of significantly altered features for the different variants tested in the adapted LP assay. illumbatchMKO.pdf analysisbatchMKO.pdf Cite Share Download PDF Status: Under Review Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5928514","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":455814066,"identity":"3780d20e-a610-4737-839b-1c03510846e5","order_by":0,"name":"Mathias 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Variants are mapped onto a schematic illustration of the LAR receptor with the Ig1-FN8 domain on top and juxtamembraneous-D2 domain on the bottom. “Control variants” are found in individuals without any psychiatric diagnosis as defined in the iPSYCH cohorts. “Shared variants” refer to missense variants found in both patients and controls. \u003cstrong\u003eb) \u003c/strong\u003eDomain-wise burden analysis of rare, missense variants of LAR with OR and 95 % confidence interval boxes. FN2 domain shows OR=3, 95 % CI: 1.33 – 7.27, two-sided uncorrected P-value = 0.006 (Fisher exact test). \u003cstrong\u003ec) \u003c/strong\u003eWestern blot analysis of selected missense variants from expression in CHO-K1 cells. Cells were left for 24 hours after transfection before lysis. Western blotting was performed with a LAR ECD specific antibody.\u003c/p\u003e","description":"","filename":"fig1.png","url":"https://assets-eu.researchsquare.com/files/rs-5928514/v1/2e621b134448906b8641cabc.png"},{"id":83768440,"identity":"137c49be-457f-40a7-81d1-af539a40fdeb","added_by":"auto","created_at":"2025-06-02 11:47:05","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":760541,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea) \u003c/strong\u003eMissense variation sites on the experimental structure of LAR FN1-4 (from PDB: 6TPW [40]). Sidechains of V389 and P417 are facing the core of their respective FN domains, while P381 is facing the hinge region between the FN1-2 domains. \u003cstrong\u003eb) \u003c/strong\u003eThermal stability of selected variants using Tycho setup. Data are represented as first-derivatives of the fluorescence 330nm/350nm ratio (n=2 pr measurement). \u003cstrong\u003ec) \u003c/strong\u003eThermoFluor plots with Boltzmann Sigmoidal fits for selected missense variant. Horizontal dashed line indicates Ti (n=3 pr variant, n=3 pr WT batch using three batches for a total of n=9 replicates). \u003cstrong\u003ed) \u003c/strong\u003eTable showing alteration in melting transition point (ºC change) compared to WT LAR FN1-4 for Tycho and ThermoFluor. \u003cstrong\u003ee-k) \u003c/strong\u003eMST traces for two replicates of LAR FN1-4 WT and indicated variants. Note that for P381L, V389M and P417L the traces cross during the MST-ON time (after purple vertical bar), indicative of temperature-dependent alterations.\u003c/p\u003e","description":"","filename":"fig2.png","url":"https://assets-eu.researchsquare.com/files/rs-5928514/v1/2cba755ced1e19f4adca8490.png"},{"id":83767624,"identity":"a9ad3295-d2c4-4d1b-a626-fe15a451ec06","added_by":"auto","created_at":"2025-06-02 11:31:05","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":1011264,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea) \u003c/strong\u003eIllustration of the transcellular aggregation assay using LAR and NGL-3. Here, separate wells of HEK293T cells are co-transfected with NGL-3 + GFP or LAR + mCherry and subsequently resuspended and mixed in solution and then analyzed with fluorescence microscopy to evaluate amount of aggregated cells \u003cstrong\u003eb) \u003c/strong\u003eQuantification of cell aggregation index (area) for LAR WT and selected variants as well as IgSF8 (negative control). Bar coloring indicates case-control status (control variants: white, case variants: dark grey). The experiment constitutes at least three biological replicates of n=4 images (12 in total) pr variant. **p=0.0047, ***p=0.0001, ****p\u0026lt;0.0001 (Kruskal-Wallis test). Data is presented as mean ± SD. \u003cstrong\u003ec) \u003c/strong\u003eRepresentative images from fluorescent microscopy of cell aggregation solutions as described in a.\u003c/p\u003e","description":"","filename":"fig3.png","url":"https://assets-eu.researchsquare.com/files/rs-5928514/v1/baaa5d3227fb4befcdd1b479.png"},{"id":83766896,"identity":"e19ae9b0-4382-4bef-8354-1e91d7d98a79","added_by":"auto","created_at":"2025-06-02 11:23:05","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":1086498,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea) \u003c/strong\u003eIllustration of \u003cem\u003ein situ \u003c/em\u003ebinding assay using LAR variant transfected HEK293T cells and Fc-NGL-3 fusion protein. Cells were transfected on coverslips and exposed to 2.5 µM soluble Fc-NGL-3 and immunostained (without permeabilization) to visualize the amount of Fc-NGL-3 binding. \u003cstrong\u003eb) \u003c/strong\u003eRepresentative fluorescent images of LAR transfected cells with surface-bound NGL-3. \u003cstrong\u003ec) \u003c/strong\u003eQuantification of surface NGL-3 binding for LAR WT and selected variants, as well as CD4 as negative control binder for NGL-3 (at least three biological replicates and n=49 cells pr replicate. ***p=0.002, ****p\u0026lt;0.0001 (Kruskal Wallis test). Data are presented as mean ± SD. \u003cstrong\u003ed) \u003c/strong\u003eLAR Surface expression quantification from NGL-3 \u003cem\u003ein situ \u003c/em\u003ebinding assay. All variants showed less signal at the cell surface\u003c/p\u003e\n\u003cp\u003ecompared to WT. *p=0.0141, ****p\u0026lt;0.0001 (Kruskal Wallis test). \u003cstrong\u003ee) \u003c/strong\u003eIllustration of artificial synaptogenesis assay using LAR transfected HEK293T cells seeded onto rat hippocampal neurons. The cells were co-cultured for 24 hours before PSD-95 assessment. \u003cstrong\u003ef) \u003c/strong\u003eRepresentative images of LAR transfected HEK293T cells in co-culture with hippocampal neurons stained for PSD-95 clustering. \u003cstrong\u003eg) \u003c/strong\u003eQuantification of PSD-95 clusters as markers of excitatory synapse formation onto LAR transfected HEK293T cells, using CD4 as a negative control. Data consists of three biological replicates with n\u0026gt;10 images pr replicate. **p\u0026lt;0.005, ****p\u0026lt;0.001 (Kruskal Wallis test). Data are presented as mean ± SD. Bar coloring in c), d) and g) indicates case-control status (control variants: white, case variants: dark grey)\u003c/p\u003e","description":"","filename":"fig4.png","url":"https://assets-eu.researchsquare.com/files/rs-5928514/v1/0bb60d3ed68c5c63b1437a03.png"},{"id":83767626,"identity":"0bbd22ee-ab1d-46e9-9145-4d2c675ca6af","added_by":"auto","created_at":"2025-06-02 11:31:05","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":939302,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea) \u003c/strong\u003ePair distance distribution function (indirect Fourier transformation [IFT] of SAXS data) of LAR variants for analysis of distance distribution histogram to estimate the shape of protein, whoing elongated plots for the three tested variants indicating elongated protein shapes. \u003cstrong\u003eb) \u003c/strong\u003eDimensionless Kratky plot based on Radius of gyration (Rg) of LAR variants for compactness and folding state analysis. \u003cstrong\u003ec) \u003c/strong\u003eStructural parameters of LAR rare variants calculated from SAXS data based on Guinier analysis and IFT. I (0), forward scattering intensity, MW, molecular weight estimate, Rg(Å) Radius of gyration, and Dmax(Å), maximum particle dimension. \u003cstrong\u003ed) \u003c/strong\u003eStructural modelling of LAR FN 1-4 and NGL-3 interaction using AlphaFold2 and \u003cstrong\u003ee) \u003c/strong\u003eMolecular docking program HDOCK.\u003c/p\u003e","description":"","filename":"fig5.png","url":"https://assets-eu.researchsquare.com/files/rs-5928514/v1/8fd988cd40aabbe4c1a01183.png"},{"id":83767629,"identity":"d972505d-3767-40fd-9490-3efa74739c2f","added_by":"auto","created_at":"2025-06-02 11:31:06","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":997471,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea) \u003c/strong\u003eGraphical illustration of adapted LP assay to evaluate morphological features elicited by LAR WT or variant overexpression in U2OS cells. Cells were multi-stained with Hoechst, MitoTracker, Phalloidin, WGA and anti-LAR in 384 well plates. Images were acquired with automated, high-content confocal microscopy and feature profiles were extracted for single cells and aggregated for each well before undergoing customized analysis. \u003cstrong\u003eb) \u003c/strong\u003eRepresentative images of the four channels from WT, P381L, V389M and P417L illustrating staining of specific compartments and identification of LAR-positive cells. \u003cstrong\u003ec-e) \u003c/strong\u003eVolcano plots illustrating changed feature types between WT LAR and P381L, V389M and P417L respectively. Dot size is scaled dependent on the p-value as illustrated. Data is from n=5-6 wells with a minimum of 20 LAR-positive cells pr well. p-value from t-test. X-axis are clipped at - 1.5 and 1.5.\u003c/p\u003e","description":"","filename":"fig6.png","url":"https://assets-eu.researchsquare.com/files/rs-5928514/v1/b59ebff54e23a87a4b286289.png"},{"id":83768988,"identity":"803689df-c7c5-4590-ae85-d8523288855d","added_by":"auto","created_at":"2025-06-02 11:55:12","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2049602,"visible":true,"origin":"","legend":"Article File","description":"","filename":"250127LARmissensemanuscriptwMM.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5928514/v1_covered_da5d5adb-6522-4790-b0d3-4923a7aeb19a.pdf"},{"id":83768227,"identity":"5e237e23-2b6a-4795-9e61-5931e05083d9","added_by":"auto","created_at":"2025-06-02 11:39:05","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":8557729,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSupplemental Figure 1: \u003c/strong\u003eWestern blots of all rare missense variants identified in the iPSYCH cohort in transfected CHO-K1 cells. Blots were developed with a polyclonal antibody against the extracellular domain of LAR. Media were also analyzed for receptor shedding. A GAPDH antibody was used to show that cell viability was comparable between transfected cells. Of note, P416S was analyzed with a new plasmid prep and looked like WT LAR (data not shown). GAPDH indicated with asterisks are from a different blot with the same samples, but the mock and WT lanes were switched. The last blot illustrates the described non-rare variants identified.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSupplemental Figure 2: a-c) \u003c/strong\u003eSide chain positions for V389 (a), P417L (b) and P381 (c) are indicated in red with intermolecular sidechains within 4 Å shown as grey sticks (from experimental structure 6TPV of LAR FN1-2 [40]). \u003cstrong\u003ed) \u003c/strong\u003eThermostability assessment using Tycho for remaining tested variants in this assay (n=2 pr variant) \u003cstrong\u003ee) \u003c/strong\u003eFluorescent changes from SYPRO Orange ThermoFluor assay showing increases in normalized SYPRO Orange fluorescence during protein unfolding for remaining tested variants (n=3 pr variant, n=3 pr batch WT, 9 replicates in total). \u003cstrong\u003ef) \u003c/strong\u003eLAR WT vs. NGL-3 with observed changes in F-norm and KD assessment. \u003cstrong\u003eg) \u003c/strong\u003eTable showing changes in KD observed for the different variants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSupplemental Figure 3: a) \u003c/strong\u003eRepresentative images of the remaining variants tested in transcellular adhesion assay. \u003cstrong\u003eb) \u003c/strong\u003eQuantification of remaining variants from the assay. No variants were significantly\u003c/p\u003e\n\u003cp\u003edifferent (Kruskal Wallis test). Bar coloring indicates case-control status (control variants: white, shared variants: light grey, case variants: dark grey).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSupplemental Figure 4: a) \u003c/strong\u003eQuantitative assessment of LAR variant surface expression in HEK293 cells in the artificial synapse formation assay. Of note, cells were selected based on their similar expression for uniform PSD-95 analysis. None of the tested variants had significantly different levels at the cell surface in this assay (Kruskal Wallis test). Data are presented as mean ± SD. \u003cstrong\u003eb) \u003c/strong\u003eRepresentative images from SALM5-Fc surface binding to LAR meA-i-meB variants in transfected HEK293 cells. The scale bar represents 30 μm. \u003cstrong\u003ec) \u003c/strong\u003eQuantification of SALM5-Fc surface binding to LAR meA-i-meB variants in transfected HEK293 cells. Among the missense variants, only P417L showed significantly decreased SALM5 binding (p=0.0007, Kruskal Wallis test). Data are presented as mean ± SD. \u003cstrong\u003ed) \u003c/strong\u003eSurface expression of the same LAR variants as in c). Only P417L showed significant changes from WT (p=0.0052, Kruskal Wallis test). Data are presented as mean ± SD. Bar coloring indicates case-control status (control variants: white, case variants: dark grey).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSupplemental Figure 5: a) \u003c/strong\u003eSAXS data plotted at log-log scale of LAR wild-type and rare variants. Y-axis depicts the scattering intensity, I(q), and x-axis shows the momentum transfer vector, q. \u003cstrong\u003eb-e) \u003c/strong\u003eSAXS data points that are used for Guinier analysis and their normalized residual plots. Points that are on the red lines are used to calculate Rg (Å). Very low angle scattering points are neglected due to parasitic scattering and aggregation artefacts.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSupplemental Figure 6: a-b) \u003c/strong\u003eAdditional model structure illustrations from AlphaFold2 and HDOCK modelling of the LAR FN1-4:NGL-3 interface. \u003cstrong\u003ec) \u003c/strong\u003ePredicted aligned error (PAE) plots of the three best AlphaFold2 models demonstrating high confidence in the interposition of the LRR domain of NGL-3 and the FN1 domain of LAR. The color code indicates the expected distance error in Ångströms (Å).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSupplemental Figure 7: a-c) \u003c/strong\u003ePairwise comparison of LAR WT and missense variants as indicated. Dot size is scaled dependent on the p-value as illustrated. Data is from n=5-6 wells with a minimum of 20 LAR-positive cells pr well.\u003c/p\u003e","description":"","filename":"250129LARSuppl.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5928514/v1/eb1c98d2334198dcd9ad131c.pdf"},{"id":83766884,"identity":"2b1d33f4-a41c-4c4d-9f8c-b1261d6eb755","added_by":"auto","created_at":"2025-06-02 11:23:05","extension":"xlsx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":18163,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eSupplementary Table 1: \u003c/strong\u003eList of significantly altered features for the different variants tested in the adapted LP assay.\u003c/p\u003e","description":"","filename":"Supplementarytable1.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-5928514/v1/c5ac39fb241bea5da2469027.xlsx"},{"id":83766886,"identity":"008c02bd-fa76-4e08-9308-3bad2b305401","added_by":"auto","created_at":"2025-06-02 11:23:05","extension":"pdf","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":72680,"visible":true,"origin":"","legend":"","description":"","filename":"illumbatchMKO.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5928514/v1/237df395f325b9f72038f378.pdf"},{"id":83766890,"identity":"58238c14-3e43-454c-9a02-c43adfaa9be8","added_by":"auto","created_at":"2025-06-02 11:23:05","extension":"pdf","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":139090,"visible":true,"origin":"","legend":"","description":"","filename":"analysisbatchMKO.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5928514/v1/d61cdaf59ab7119311c3b1a6.pdf"}],"financialInterests":"\u003cb\u003eYes\u003c/b\u003e\nADB has received speaker fee from Lundbeck.\r\nThe remaining authors declare no conflicts of interest.","formattedTitle":"Rare missense variants of the leukocyte common antigen related receptor (LAR) display reduced activity in transcellular adhesion and synapse formation","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"translational-psychiatry","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"tp","sideBox":"Learn more about [Translational Psychiatry](http://www.nature.com/tp/)","snPcode":"41398","submissionUrl":"https://mts-tp.nature.com/cgi-bin/main.plex","title":"Translational Psychiatry","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-5928514/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5928514/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The leukocyte common antigen related receptor (LAR) is a member of the LAR receptor protein tyrosine phosphatase (RPTP) family of synaptic adhesion molecules that contribute to the proper alignment and specialization of synaptic connections in the mammalian brain. LAR-RPTP members have been genetically associated with neuropsychiatric disorders, but the molecular consequences of genetic perturbations of LAR remain unstudied. Using exome sequencing data from psychiatric patients and controls, we identify rare missense variants of LAR that render the extracellular domain (ECD) unstable and susceptible to proteolytic cleavage. Using recombinant and cellular systems, we describe three variants that cause disruption of the LAR:NGL-3 interaction, which results in loss of transcellular adhesion and synaptogenic effects. Furthermore, we show that overexpression of two of these variants elicit altered morphological phenotypes in an imaging-based morphological profiling assay compared to wild type LAR, suggesting that destabilization of the LAR ECD has broad effects on LAR function. In conclusion, our study identifies three rare, missense variants in LAR that could provide insights into LAR involvement with psychiatric pathobiology.","manuscriptTitle":"Rare missense variants of the leukocyte common antigen related receptor (LAR) display reduced activity in transcellular adhesion and synapse formation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-06-02 11:23:00","doi":"10.21203/rs.3.rs-5928514/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"translational-psychiatry","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"tp","sideBox":"Learn more about [Translational Psychiatry](http://www.nature.com/tp/)","snPcode":"41398","submissionUrl":"https://mts-tp.nature.com/cgi-bin/main.plex","title":"Translational Psychiatry","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"26907701-122b-46b7-ba9e-5dd054209daf","owner":[],"postedDate":"June 2nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":48450482,"name":"Biological sciences/Neuroscience"},{"id":48450483,"name":"Health sciences/Diseases/Psychiatric disorders/ADHD"}],"tags":[],"updatedAt":"2025-06-02T11:23:01+00:00","versionOfRecord":[],"versionCreatedAt":"2025-06-02 11:23:00","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5928514","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5928514","identity":"rs-5928514","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}