PUBLICATION

Myofibrillar myopathy hallmarks associated with ZAK deficiency

Authors
Stonadge, A., Genzor, A.V., Russell, A., Hamed, M.F., Romero, N., Evans, G., Pownall, B., Bekker-Jensen, S., Blanco, G.
ID
ZDB-PUB-230712-35
Date
2023
Source
Human molecular genetics   32(17): 2751-2770 (Journal)
Registered Authors
Pownall, Betsy
Keywords
none
MeSH Terms
  • Adaptor Proteins, Signal Transducing/genetics
  • Animals
  • Apoptosis Regulatory Proteins/genetics
  • Filamins/genetics
  • Filamins/metabolism
  • Humans
  • Mice
  • Muscle, Skeletal/metabolism
  • Mutation
  • Myopathies, Structural, Congenital*/metabolism
  • Protein Isoforms/genetics
  • Zebrafish*/genetics
  • Zebrafish*/metabolism
  • Zebrafish Proteins/genetics
PubMed
37427997 Full text @ Hum. Mol. Genet.
Abstract
The ZAK gene encodes two functionally distinct kinases, ZAKɑ and ZAKβ. Homozygous loss of function mutations affecting both isoforms cause a congenital muscle disease. ZAKβ is the only isoform expressed in skeletal muscle and is activated by muscle contraction and cellular compression. The ZAKβ substrates in skeletal muscle or the mechanism whereby ZAKβ senses mechanical stress remain to be determined. To gain insights into the pathogenic mechanism, we exploited ZAK-deficient cell lines, zebrafish, mice and a human biopsy. ZAK-deficient mice and zebrafish show a mild phenotype. In mice, comparative histopathology data from regeneration, overloading, ageing and sex conditions indicate that while age and activity are drivers of the pathology, ZAKβ appears to have a marginal role in myoblast fusion in vitro or muscle regeneration in vivo. The presence of SYNPO2, BAG3 and FLNC in a phosphoproteomics assay and extended analyses suggested a role for ZAKβ in the turnover of FLNC. Immunofluorescence analysis of muscle sections from mice and a human biopsy showed evidence of FLNC and BAG3 accumulations as well as other myofibrillar myopathy markers. Moreover, endogenous overloading of skeletal muscle exacerbated the presence of fibres with FLNC accumulations in mice, indicating that ZAKβ signalling is necessary for an adaptive turnover of FLNC that allows for the normal physiological response to sustained mechanical stress. We suggest that accumulation of mislocalized FLNC and BAG3 in highly immunoreactive fibres contributes to the pathogenic mechanism of ZAK-deficiency.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping