The analysis of heterotaxy patients reveals new loss-of-function variants of GRK5

Davor Lessel, Tariq Muhammad, Teresa Casar Tena, Barbara Moepps, Martin D. Burkhalter, Marc Phillip Hitz, Okan Toka, Axel Rentzsch, Stephan Schubert, Adelheid Schalinski, Ulrike M.M. Bauer, Christian Kubisch, Stephanie M. Ware, Melanie Philipp

Research output: Contribution to journalArticle

Abstract

G protein-coupled receptor kinase 5 (GRK5) is a regulator of cardiac performance and a potential therapeutic target in heart failure in the adult. Additionally, we have previously classified GRK5 as a determinant of left-right asymmetry and proper heart development using zebrafish. We thus aimed to identify GRK5 variants of functional significance by analysing 187 individuals with laterality defects (heterotaxy) that were associated with a congenital heart defect (CHD). Using Sanger sequencing we identified two moderately frequent variants in GRK5 with minor allele frequencies <10%, and seven very rare polymorphisms with minor allele frequencies <1%, two of which are novel variants. Given their evolutionarily conserved position in zebrafish, in-depth functional characterisation of four variants (p.Q41L, p.G298S, p.R304C and p.T425M) was performed. We tested the effects of these variants on normal subcellular localisation and the ability to desensitise receptor signalling as well as their ability to correct the left-right asymmetry defect upon Grk5l knockdown in zebrafish. While p.Q41L, p.R304C and p.T425M responded normally in the first two aspects, neither p.Q41L nor p.R304C were capable of rescuing the lateralisation phenotype. The fourth variant, p.G298S was identified as a complete loss-of-function variant in all assays and provides insight into the functions of GRK5.

Original languageEnglish (US)
Article number33231
JournalScientific reports
Volume6
DOIs
StatePublished - Sep 13 2016

    Fingerprint

ASJC Scopus subject areas

  • General

Cite this

Lessel, D., Muhammad, T., Casar Tena, T., Moepps, B., Burkhalter, M. D., Hitz, M. P., Toka, O., Rentzsch, A., Schubert, S., Schalinski, A., Bauer, U. M. M., Kubisch, C., Ware, S. M., & Philipp, M. (2016). The analysis of heterotaxy patients reveals new loss-of-function variants of GRK5. Scientific reports, 6, [33231]. https://doi.org/10.1038/srep33231