Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.747380
Title: Clathrin light chains modulate the biophysical properties and function of clathrin
Author: Redlingshoefer, Lisa
ISNI:       0000 0004 7230 2761
Awarding Body: UCL (University College London)
Current Institution: University College London (University of London)
Date of Award: 2018
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Abstract:
Clathrin triskelia are formed from three pairs of clathrin light and heavy chains (CLCs and CHCs). These are recruited by adaptor proteins for assembly into membrane-associated, macromolecular lattices that form cargo-loaded transport vesicles. CLC variability is highly conserved between species and further expanded by tissue-specific splicing and expression, suggesting distinct functions for the two CLC isoforms. As CLCs enforce clathrin rigidity and stability, we hypothesize that CLC variability diversifies the biophysical properties of clathrin to accommodate specialised function in different tissues. Immunoprecipitation experiments from tissue and cultured cells expressing the two CLC isoforms revealed that triskelia are of homogeneous CLC composition. Clathrin reconstitution experiments in vitro confirmed that this CLC segregation occurs spontaneously. Structural and biophysical characterisation of clathrin variants showed that CLCs differentially alter the stability, conformation and possibly interaction of clathrin, resulting in varying assembly properties in vitro. A functional role for this was demonstrated when single neuronal clathrin variants were found less able to deform membrane in vitro and disassembled more rapidly than non-neuronal variants. EM analysis demonstrated that different clathrin isoforms co-assemble into heterogeneous lattices. Their properties were significantly different from single isoform lattices, suggesting that CLC composition within assemblies is an important tool to regulate clathrin function. In vivo evidence was gathered form CLCa-KO mice displaying decimated synaptic vesicle pools, supporting the idea that a mix of neuronal CLC isoforms is necessary to create appropriate clathrin biophysical properties and function in neurons. In conclusion, this study revealed that CLC isoforms segregate on clathrin triskelia, but not during lattice formation, underscoring the functional difference between CLC isoforms. The work presented here demonstrates a role for CLC composition in clathrin coat function and for the first time provides a model for the function of alternative CLC splicing in neurons.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.747380  DOI: Not available
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