A homozygous MRPL24 mutation causes a complex movement disorder and affects the mitoribosome assembly: Neurobiology of Disease

M. Di Nottia, M. Marchese, D. Verrigni, C.D. Mutti, A. Torraco, R. Oliva, E. Fernandez-Vizarra, F. Morani, G. Trani, T. Rizza, D. Ghezzi, A. Ardissone, C. Nesti, G. Vasco, M. Zeviani, M. Minczuk, E. Bertini, F.M. Santorelli, R. Carrozzo

Research output: Contribution to journalArticlepeer-review

Abstract

Mitochondrial ribosomal protein large 24 (MRPL24) is 1 of the 82 protein components of mitochondrial ribosomes, playing an essential role in the mitochondrial translation process. We report here on a baby girl with cerebellar atrophy, choreoathetosis of limbs and face, intellectual disability and a combined defect of complexes I and IV in muscle biopsy, caused by a homozygous missense mutation identified in MRPL24. The variant predicts a Leu91Pro substitution at an evolutionarily conserved site. Using human mutant cells and the zebrafish model, we demonstrated the pathological role of the identified variant. In fact, in fibroblasts we observed a significant reduction of MRPL24 protein and of mitochondrial respiratory chain complex I and IV subunits, as well a markedly reduced synthesis of the mtDNA-encoded peptides. In zebrafish we demonstrated that the orthologue gene is expressed in metabolically active tissues, and that gene knockdown induced locomotion impairment, structural defects and low ATP production. The motor phenotype was complemented by human WT but not mutant cRNA. Moreover, sucrose density gradient fractionation showed perturbed assembly of large subunit mitoribosomal proteins, suggesting that the mutation leads to a conformational change in MRPL24, which is expected to cause an aberrant interaction of the protein with other components of the 39S mitoribosomal subunit. © 2020 The Authors
Original languageEnglish
JournalNeurobiol. Dis.
Volume141
DOIs
Publication statusPublished - 2020

Keywords

  • Mitochondrial disorders
  • Mitochondrial protein synthesis
  • Mitoribosomes
  • Molecular modeling
  • Movement disorder
  • MRPL24
  • Protein interactions
  • Zebrafish
  • adenosine triphosphate
  • carnitine
  • cytochrome c oxidase
  • idebenone
  • leucine
  • mitochondrial DNA
  • MRPL24 protein
  • proline
  • reduced nicotinamide adenine dinucleotide dehydrogenase (ubiquinone)
  • riboflavin
  • ribosome protein
  • unclassified drug
  • adolescent
  • amino acid substitution
  • animal experiment
  • animal model
  • animal tissue
  • Article
  • case report
  • cerebellum atrophy
  • choreoathetosis
  • clinical article
  • conformational transition
  • controlled study
  • embryo
  • female
  • fibroblast
  • gene
  • gene expression
  • gene knockdown
  • gene mutation
  • genetic conservation
  • human
  • human cell
  • human tissue
  • intellectual impairment
  • missense mutation
  • mitochondrial ribosome
  • motor dysfunction
  • MRPL24 gene
  • muscle biopsy
  • nonhuman
  • priority journal
  • protein assembly
  • protein interaction
  • ribosomal subunit
  • sucrose density gradient centrifugation
  • Wolff Parkinson White syndrome

Fingerprint Dive into the research topics of 'A homozygous MRPL24 mutation causes a complex movement disorder and affects the mitoribosome assembly: Neurobiology of Disease'. Together they form a unique fingerprint.

Cite this