Back to Search Start Over

Pediatric Dilated Cardiomyopathy‐Associated LRRC10 (Leucine‐Rich Repeat–Containing 10) Variant Reveals LRRC10 as an Auxiliary Subunit of Cardiac L‐Type Ca2+ Channels

Authors :
Ravi C. Balijepalli
Youngsook Lee
Marites T. Woon
Martin R. Lea
Jared M. Evans
Timothy M. Olson
Alexis M Keefe
Pamela A. Long
Louise Reilly
Carl J. Beglinger
Timothy J. Kamp
Source :
Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease
Publication Year :
2018
Publisher :
John Wiley and Sons Inc., 2018.

Abstract

Background Genetic causes of dilated cardiomyopathy (DCM) are incompletely understood. LRRC10 (leucine‐rich repeat–containing 10) is a cardiac‐specific protein of unknown function. Heterozygous mutations in LRRC10 have been suggested to cause DCM, and deletion of Lrrc10 in mice results in DCM. Methods and Results Whole‐exome sequencing was carried out on a patient who presented at 6 weeks of age with DCM and her unaffected parents, filtering for rare, deleterious, recessive, and de novo variants. Whole‐exome sequencing followed by trio‐based filtering identified a homozygous recessive variant in LRRC10 , I195T. Coexpression of I195T LRRC10 with the L‐type Ca 2+ channel (Ca v 1.2, β 2CN2 , and α 2 δ subunits) in HEK293 cells resulted in a significant ≈0.5‐fold decrease in I Ca,L at 0 mV, in contrast to the ≈1.4‐fold increase in I Ca,L by coexpression of LRRC10 (n=9–12, P LRRC10 or I195T LRRC10 did not alter the surface membrane expression of Ca v 1.2. LRRC10 coexpression with Ca v 1.2 in the absence of auxiliary β 2CN2 and α 2 δ subunits revealed coassociation of Ca v 1.2 and LRRC10 and a hyperpolarizing shift in the voltage dependence of activation (n=6–9, P Lrrc10 −/− mice had significantly smaller I Ca,L , and coimmunoprecipitation experiments confirmed association between LRRC10 and the Ca v 1.2 subunit in mouse hearts. Conclusions Examination of a patient with DCM revealed homozygosity for a previously unreported LRRC10 variant: I195T. Wild‐type and I195T LRRC10 function as cardiac‐specific subunits of L‐type Ca 2+ channels and exert dramatically different effects on channel gating, providing a potential link to DCM.

Details

Language :
English
ISSN :
20479980
Volume :
7
Issue :
3
Database :
OpenAIRE
Journal :
Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease
Accession number :
edsair.doi.dedup.....11a3a7afa7851146edd0acfa591b4dcd