Differential effects of human L1CAM mutations on complementing guidance and synaptic defects in Drosophila melanogaster.

A large number of different pathological L1CAM mutations have been identified that result in a broad spectrum of neurological and non-neurological phenotypes. While many of these mutations have been characterized for their effects on homophilic and heterophilic interactions, as well as expression le...

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Main Authors: Sirisha Kudumala, Julie Freund, Michael Hortsch, Tanja A Godenschwege
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2013-01-01
Series:PLoS ONE
Online Access:http://europepmc.org/articles/PMC3796554?pdf=render
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author Sirisha Kudumala
Julie Freund
Michael Hortsch
Tanja A Godenschwege
author_facet Sirisha Kudumala
Julie Freund
Michael Hortsch
Tanja A Godenschwege
author_sort Sirisha Kudumala
collection DOAJ
description A large number of different pathological L1CAM mutations have been identified that result in a broad spectrum of neurological and non-neurological phenotypes. While many of these mutations have been characterized for their effects on homophilic and heterophilic interactions, as well as expression levels in vitro, there are only few studies on their biological consequences in vivo. The single L1-type CAM gene in Drosophila, neuroglian (nrg), has distinct functions during axon guidance and synapse formation and the phenotypes of nrg mutants can be rescued by the expression of human L1CAM. We previously showed that the highly conserved intracellular FIGQY Ankyrin-binding motif is required for L1CAM-mediated synapse formation, but not for neurite outgrowth or axon guidance of the Drosophila giant fiber (GF) neuron. Here, we use the GF as a model neuron to characterize the pathogenic L120V, Y1070C, C264Y, H210Q, E309K and R184Q extracellular L1CAM missense mutations and a L1CAM protein with a disrupted ezrin-moesin-radixin (ERM) binding site to investigate the signaling requirements for neuronal development. We report that different L1CAM mutations have distinct effects on axon guidance and synapse formation. Furthermore, L1CAM homophilic binding and signaling via the ERM motif is essential for axon guidance in Drosophila. In addition, the human pathological H210Q, R184Q and Y1070C, but not the E309K and L120V L1CAM mutations affect outside-in signaling via the FIGQY Ankyrin binding domain which is required for synapse formation. Thus, the pathological phenotypes observed in humans are likely to be caused by the disruption of signaling required for both, guidance and synaptogenesis.
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spelling doaj.art-385c97b5f7bc4cd088311f63203419ce2022-12-21T18:40:52ZengPublic Library of Science (PLoS)PLoS ONE1932-62032013-01-01810e7697410.1371/journal.pone.0076974Differential effects of human L1CAM mutations on complementing guidance and synaptic defects in Drosophila melanogaster.Sirisha KudumalaJulie FreundMichael HortschTanja A GodenschwegeA large number of different pathological L1CAM mutations have been identified that result in a broad spectrum of neurological and non-neurological phenotypes. While many of these mutations have been characterized for their effects on homophilic and heterophilic interactions, as well as expression levels in vitro, there are only few studies on their biological consequences in vivo. The single L1-type CAM gene in Drosophila, neuroglian (nrg), has distinct functions during axon guidance and synapse formation and the phenotypes of nrg mutants can be rescued by the expression of human L1CAM. We previously showed that the highly conserved intracellular FIGQY Ankyrin-binding motif is required for L1CAM-mediated synapse formation, but not for neurite outgrowth or axon guidance of the Drosophila giant fiber (GF) neuron. Here, we use the GF as a model neuron to characterize the pathogenic L120V, Y1070C, C264Y, H210Q, E309K and R184Q extracellular L1CAM missense mutations and a L1CAM protein with a disrupted ezrin-moesin-radixin (ERM) binding site to investigate the signaling requirements for neuronal development. We report that different L1CAM mutations have distinct effects on axon guidance and synapse formation. Furthermore, L1CAM homophilic binding and signaling via the ERM motif is essential for axon guidance in Drosophila. In addition, the human pathological H210Q, R184Q and Y1070C, but not the E309K and L120V L1CAM mutations affect outside-in signaling via the FIGQY Ankyrin binding domain which is required for synapse formation. Thus, the pathological phenotypes observed in humans are likely to be caused by the disruption of signaling required for both, guidance and synaptogenesis.http://europepmc.org/articles/PMC3796554?pdf=render
spellingShingle Sirisha Kudumala
Julie Freund
Michael Hortsch
Tanja A Godenschwege
Differential effects of human L1CAM mutations on complementing guidance and synaptic defects in Drosophila melanogaster.
PLoS ONE
title Differential effects of human L1CAM mutations on complementing guidance and synaptic defects in Drosophila melanogaster.
title_full Differential effects of human L1CAM mutations on complementing guidance and synaptic defects in Drosophila melanogaster.
title_fullStr Differential effects of human L1CAM mutations on complementing guidance and synaptic defects in Drosophila melanogaster.
title_full_unstemmed Differential effects of human L1CAM mutations on complementing guidance and synaptic defects in Drosophila melanogaster.
title_short Differential effects of human L1CAM mutations on complementing guidance and synaptic defects in Drosophila melanogaster.
title_sort differential effects of human l1cam mutations on complementing guidance and synaptic defects in drosophila melanogaster
url http://europepmc.org/articles/PMC3796554?pdf=render
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AT michaelhortsch differentialeffectsofhumanl1cammutationsoncomplementingguidanceandsynapticdefectsindrosophilamelanogaster
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