Dataset Information

Structural Basis of Diverse Homophilic Recognition by Clustered ?- and ?-Protocadherins.

ABSTRACT: Clustered protocadherin proteins (?-, ?-, and ?-Pcdhs) provide a high level of cell-surface diversity to individual vertebrate neurons, engaging in highly specific homophilic interactions to mediate important roles in mammalian neural circuit development. How Pcdhs bind homophilically through their extracellular cadherin (EC) domains among dozens of highly similar isoforms has not been determined. Here, we report crystal structures for extracellular regions from four mouse Pcdh isoforms (?4, ?7, ?6, and ?8), revealing a canonical head-to-tail interaction mode for homophilic trans dimers comprising primary intermolecular EC1:EC4 and EC2:EC3 interactions. A subset of trans interface residues exhibit isoform-specific conservation, suggesting roles in recognition specificity. Mutation of these residues, along with trans-interacting partner residues, altered the specificities of Pcdh interactions. Together, these data show how sequence variation among Pcdh isoforms encodes their diverse strict homophilic recognition specificities, which are required for their key roles in neural circuit assembly.

SUBMITTER: Goodman KM

PROVIDER: S-EPMC4873334 | biostudies-literature | 2016 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Structural Basis of Diverse Homophilic Recognition by Clustered α- and β-Protocadherins.

Goodman Kerry Marie KM Rubinstein Rotem R Thu Chan Aye CA Bahna Fabiana F Mannepalli Seetha S Ahlsén Göran G Rittenhouse Chelsea C Maniatis Tom T Honig Barry B Shapiro Lawrence L

Neuron 20160505 4

Clustered protocadherin proteins (α-, β-, and γ-Pcdhs) provide a high level of cell-surface diversity to individual vertebrate neurons, engaging in highly specific homophilic interactions to mediate important roles in mammalian neural circuit development. How Pcdhs bind homophilically through their extracellular cadherin (EC) domains among dozens of highly similar isoforms has not been determined. Here, we report crystal structures for extracellular regions from four mouse Pcdh isoforms (α4, α7, ...[more]

PMID: 27161523

Similar Datasets

Project description:Neuronal identity is generated by the cell-surface expression of clustered protocadherin (Pcdh) isoforms. In mice, 58 isoforms from three gene clusters, Pcdhα, Pcdhβ, and Pcdhγ, are differentially expressed in neurons. Since cis-heteromeric Pcdh oligomers on the cell surface interact homophilically with that in other neurons in trans, it has been thought that the Pcdh isoform repertoire determines the binding specificity of synapses. We previously described the cooperative functions of isoforms from all three Pcdh gene clusters in neuronal survival and synapse formation in the spinal cord. However, the neuronal loss and the following neonatal lethality prevented an analysis of the postnatal development and characteristics of the clustered-Pcdh-null (Δαβγ) neural circuits. Here, we used two methods, one to generate the chimeric mice that have transplanted Δαβγ neurons into mouse embryos, and the other to generate double mutant mice harboring null alleles of both the Pcdh gene and the proapoptotic gene Bax to prevent neuronal loss. First, our results showed that the surviving chimeric mice that had a high contribution of Δαβγ cells exhibited paralysis and died in the postnatal period. An analysis of neuronal survival in postnatally developing brain regions of chimeric mice clarified that many Δαβγ neurons in the forebrain were spared from apoptosis, unlike those in the reticular formation of the brainstem. Second, in Δαβγ/Bax null double mutants, the central pattern generator (CPG) for locomotion failed to create a left-right alternating pattern even in the absence of neurodegeneraton. Third, calcium imaging of cultured hippocampal neurons showed that the network activity of Δαβγ neurons tended to be more synchronized and lost the variability in the number of simultaneously active neurons observed in the control network. Lastly, a comparative analysis for trans-homophilic interactions of the exogenously introduced single Pcdh-γA3 isoforms between the control and the Δαβγ neurons suggested that the isoform-specific trans-homophilic interactions require a complete match of the expressed isoform repertoire at the contacting sites between interactive neurons. These results suggested that combinations of clustered Pcdh isoforms are required for building appropriate neural circuits.

Dataset Information

Structural Basis of Diverse Homophilic Recognition by Clustered ?- and ?-Protocadherins.

Publications

Structural Basis of Diverse Homophilic Recognition by Clustered α- and β-Protocadherins.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets