TY - JOUR
T1 - Novel defect in phosphatidylinositol 4-kinase type 2-alpha (PI4K2A) at the membrane-enzyme interface is associated with metabolic cutis laxa
AU - Mohamed, Miski
AU - Gardeitchik, Thatjana
AU - Balasubramaniam, Shanti
AU - Guerrero-Castillo, Sergio
AU - Dalloyaux, Daisy
AU - van Kraaij, Sanne
AU - Venselaar, Hanka
AU - Hoischen, Alexander
AU - Urban, Zsolt
AU - Brandt, Ulrich
AU - Al-Shawi, Raya
AU - Simons, J. Paul
AU - Frison, Michele
AU - Ngu, Lock Hock
AU - Callewaert, Bert
AU - Spelbrink, Hans
AU - Kallemeijn, Wouter W.
AU - Aerts, Johannes M.F.G.
AU - Waugh, Mark G.
AU - Morava, Eva
AU - Wevers, Ron A.
N1 - Publisher Copyright:
© 2020 The Authors. Journal of Inherited Metabolic Disease published by John Wiley & Sons Ltd on behalf of SSIEM
PY - 2020/11
Y1 - 2020/11
N2 - 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.
AB - 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.
KW - PI4K2A
KW - choreoathetosis
KW - cutis laxa
KW - inborn error of metabolism
KW - movement disorder
KW - neurocutaneous disorder
KW - neurometabolism
KW - phosphatidyl inositol
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UR - http://www.scopus.com/inward/citedby.url?scp=85087182789&partnerID=8YFLogxK
U2 - 10.1002/jimd.12255
DO - 10.1002/jimd.12255
M3 - Article
C2 - 32418222
AN - SCOPUS:85087182789
SN - 0141-8955
VL - 43
SP - 1382
EP - 1391
JO - Journal of inherited metabolic disease
JF - Journal of inherited metabolic disease
IS - 6
ER -