Binding of the periplakin linker requires vimentin acidic residues D176 and E187

Elena Odintsova,Penelope Rodriguez-Zamora,Timothy Knowles,Tzu-Han Huang,Claudia Fogl,Pooja Sridhar,Catharine Trieber,Caezar Al-Jassar,Martyn Chidgey,Jitendra Kumar,Mark Jeeves,Fiyaz Mohammed,Michael Overduin

doi:10.1038/s42003-020-0810-y

Elena Odintsova, Penelope Rodriguez-Zamora + Show 11 more

Open Access

https://doi.org/10.1038/s42003-020-0810-y

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Abstract

Plakin proteins form connections that link the cell membrane to the intermediate filament cytoskeleton. Their interactions are mediated by a highly conserved linker domain through an unresolved mechanism. Here analysis of the human periplakin linker domain structure reveals a bi-lobed module transected by an electropositive groove. Key basic residues within the periplakin groove are vital for co-localization with vimentin in human cells and compromise direct binding which also requires acidic residues D176 and E187 in vimentin. We propose a model whereby basic periplakin linker domain residues recognize acidic vimentin side chains and form a complementary binding groove. The model is shared amongst diverse linker domains and can be used to investigate the effects of pathogenic mutations in the desmoplakin linker associated with arrhythmogenic right ventricular cardiomyopathy. Linker modules either act solely or collaborate with adjacent plakin repeat domains to create strong and adaptable tethering within epithelia and cardiac muscle.

Highlights

Introduction of the Arrhythmogenic right ventricular cardiomyopathy (ARVC) mutationR2541K (Supplementary Fig. 1a)[29] into the desmoplakin linker domain showed a similar effect to the K2463E/R2464E mutant
In an attempt to verify the crystal structure and resolve issues arising from the hexahistidine tag, and the lack of N-terminal residues (K1646–L1654) that are relatively conserved across the plakin family and highly conserved in periplakins from different species (Supplementary Fig. 2a, b), we attempted to determine the solution structure by nuclear magnetic resonance (NMR)
Charge reversal mutations in the vimentinROD abolish periplakin linker binding in a comparable way to how they abrogate envoplakin plakin repeat domains (PRDs) binding to vimentin[3]

Summary

Introduction

R2541K (Supplementary Fig. 1a)[29] into the desmoplakin linker domain showed a similar effect to the K2463E/R2464E mutant. The mutant distributed predominantly to the plasma membrane and exhibited a reduced MOC (Fig. 3b, c). Only minor alterations in the 1H,15N NMR spectra were observed when compared to the wild-type linker protein (Supplementary Fig. 6a). The majority of residues exhibiting the largest chemical shift a K2494 K2523 R2464 K2463 R2522 H2 C2501 R2464 E2502 C H3 S2 S1 H2 H1 R2541 K2463

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