s41467-023-43148-8.pdf (9.28 MB)
Architecture and regulation of a GDNF-GFRα1 synaptic adhesion assembly.
journal contributionposted on 2023-11-28, 10:13 authored by FM Houghton, SE Adams, AS Ríos, L Masino, AG Purkiss, DC Briggs, F Ledda, NQ McDonald
Glial-cell line derived neurotrophic factor (GDNF) bound to its co-receptor GFRα1 stimulates the RET receptor tyrosine kinase, promoting neuronal survival and neuroprotection. The GDNF-GFRα1 complex also supports synaptic cell adhesion independently of RET. Here, we describe the structure of a decameric GDNF-GFRα1 assembly determined by crystallography and electron microscopy, revealing two GFRα1 pentamers bridged by five GDNF dimers. We reconsitituted the assembly between adhering liposomes and used cryo-electron tomography to visualize how the complex fulfils its membrane adhesion function. The GFRα1:GFRα1 pentameric interface was further validated both in vitro by native PAGE and in cellulo by cell-clustering and dendritic spine assays. Finally, we provide biochemical and cell-based evidence that RET and heparan sulfate cooperate to prevent assembly of the adhesion complex by competing for the adhesion interface. Our results provide a mechanistic framework to understand GDNF-driven cell adhesion, its relationship to trophic signalling, and the central role played by GFRα1.
Crick (Grant ID: CC2068, Grant title: McDonald CC2068) Crick (Grant ID: CC1068, Grant title: STP Structural Biology)