Deleterious assembly of the lamin A/C mutant p.S143P causes ER stress in familial dilated cardiomyopathy

A1 Journal article (refereed)


Internal Authors/Editors


Publication Details

List of Authors: West G, Gullmets J, Virtanen L, Li SP, Keinanen A, Shimi T, Mauermann M, Helio T, Kaartinen M, Ollila L, Kuusisto J, Eriksson JE, Goldman RD, Herrmann H, Taimen P
Publisher: COMPANY OF BIOLOGISTS LTD
Publication year: 2016
Journal: Journal of Cell Science
Journal acronym: J CELL SCI
Volume number: 129
Issue number: 14
Start page: 2732
End page: 2743
Number of pages: 12
ISSN: 0021-9533
eISSN: 1477-9137


Abstract

Mutation of the LMNA gene, encoding nuclear lamin A and lamin C (hereafter lamin A/C), is a common cause of familial dilated cardiomyopathy (DCM). Among Finnish DCM patients, the founder mutation c.427T>C (p.S143P) is the most frequently reported genetic variant. Here, we show that p.S143P lamin A/C is more nucleoplasmic and soluble than wild-type lamin A/C and accumulates into large intranuclear aggregates in a fraction of cultured patient fibroblasts as well as in cells ectopically expressing either FLAG- or GFP-tagged p.S143P lamin A. In fluorescence loss in photobleaching (FLIP) experiments, non-aggregated EGFP-tagged p.S143P lamin A was significantly more dynamic. In in vitro association studies, p.S143P lamin A failed to form appropriate filament structures but instead assembled into disorganized aggregates similar to those observed in patient cell nuclei. A whole-genome expression analysis revealed an elevated unfolded protein response (UPR) in cells expressing p.S143P lamin A/C. Additional endoplasmic reticulum (ER) stress induced by tunicamycin reduced the viability of cells expressing mutant lamin further. In summary, p.S143P lamin A/C affects normal lamina structure and influences the cellular stress response, homeostasis and viability.


Keywords

Dilated cardiomyopathy, ER stress, Lamin, Laminopathy, UPR

Last updated on 2019-23-10 at 02:40