Novel defect in phosphatidylinositol 4-kinase type 2-alpha (PI4K2A) at the membrane-enzyme interface is associated with metabolic cutis laxa

Miski Mohamed, Thatjana Gardeitchik, Shanti Balasubramaniam, Sergio Guerrero-Castillo, Daisy Dalloyaux, Sanne van Kraaij, Hanka Venselaar, Alexander Hoischen, Zsolt Urban, Ulrich Brandt, Raya Al-Shawi, J. Paul Simons, Michele Frison, Lock Hock Ngu, Bert Callewaert, Hans Spelbrink, Wouter W. Kallemeijn, Johannes M.F.G. Aerts, Mark G. Waugh, Eva MoravaRon A. Wevers

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Inherited cutis laxa, or inelastic, sagging skin is a genetic condition of premature and generalised connective tissue ageing, affecting various elastic components of the extracellular matrix. Several cutis laxa syndromes are inborn errors of metabolism and lead to severe neurological symptoms. In a patient with cutis laxa, a choreoathetoid movement disorder, dysmorphic features and intellectual disability we performed exome sequencing to elucidate the underlying genetic defect. We identified the amino acid substitution R275W in phosphatidylinositol 4-kinase type IIα, caused by a homozygous missense mutation in the PI4K2A gene. We used lipidomics, complexome profiling and functional studies to measure phosphatidylinositol 4-phosphate synthesis in the patient and evaluated PI4K2A deficient mice to define a novel metabolic disorder. The R275W residue, located on the surface of the protein, is involved in forming electrostatic interactions with the membrane. The catalytic activity of PI4K2A in patient fibroblasts was severely reduced and lipid mass spectrometry showed that particular acyl-chain pools of PI4P and PI(4,5)P2 were decreased. Phosphoinositide lipids play a major role in intracellular signalling and trafficking and regulate the balance between proliferation and apoptosis. Phosphatidylinositol 4-kinases such as PI4K2A mediate the first step in the main metabolic pathway that generates PI4P, PI(4,5)P2 and PI(3,4,5)P3. Although neurologic involvement is common, cutis laxa has not been reported previously in metabolic defects affecting signalling. Here we describe a patient with a complex neurological phenotype, premature ageing and a mutation in PI4K2A, illustrating the importance of this enzyme in the generation of inositol lipids with particular acylation characteristics.

Original languageEnglish (US)
Pages (from-to)1382-1391
Number of pages10
JournalJournal of inherited metabolic disease
Volume43
Issue number6
DOIs
StatePublished - Nov 2020

Keywords

  • PI4K2A
  • choreoathetosis
  • cutis laxa
  • inborn error of metabolism
  • movement disorder
  • neurocutaneous disorder
  • neurometabolism
  • phosphatidyl inositol

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)

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