TY - JOUR
T1 - A missense allele of PEX5 is responsible for the defective import of PTS2 cargo proteins into peroxisomes
AU - Ali, Muhammad
AU - Khan, Shahid Y.
AU - Rodrigues, Tony A.
AU - Francisco, Tânia
AU - Jiao, Xiaodong
AU - Qi, Hang
AU - Kabir, Firoz
AU - Irum, Bushra
AU - Rauf, Bushra
AU - Khan, Asma A.
AU - Mehmood, Azra
AU - Naeem, Muhammad Asif
AU - Assir, Muhammad Zaman
AU - Ali, Muhammad Hassaan
AU - Shahzad, Mohsin
AU - Abu-Amero, Khaled K.
AU - Akram, Shehla Javed
AU - Akram, Javed
AU - Riazuddin, Sheikh
AU - Riazuddin, Saima
AU - Robinson, Michael L.
AU - Baes, Myriam
AU - Azevedo, Jorge E.
AU - Hejtmancik, J. Fielding
AU - Riazuddin, S. Amer
N1 - Funding Information:
The authors are grateful to all the members for their participation in this study. The work was supported by National Eye Institute Grant R01EY022714 (SAR). Work in JEA Laboratory was financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project PTDC/BEX-BCM/2311/2014 (POCI-01-0145-FEDER-016613) and the projects "Institute for Research and Innovation in Health Sciences" (POCI-01-0145-FEDER-007274) and NORTE-01-0145-FEDER-000008 -Porto Neurosciences and Neurologic Disease Research Initiative at I3S, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). TF and TAR are supported by Fundação para a Ciência e Tecnologia, Programa Operacional Potencial Humano do QREN, and Fundo Social Europeu.
Publisher Copyright:
© 2021, Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2021/4
Y1 - 2021/4
N2 - Peroxisomes, single-membrane intracellular organelles, play an important role in various metabolic pathways. The translocation of proteins from the cytosol to peroxisomes depends on peroxisome import receptor proteins and defects in peroxisome transport result in a wide spectrum of peroxisomal disorders. Here, we report a large consanguineous family with autosomal recessive congenital cataracts and developmental defects. Genome-wide linkage analysis localized the critical interval to chromosome 12p with a maximum two-point LOD score of 4.2 (θ = 0). Next-generation exome sequencing identified a novel homozygous missense variant (c.653 T > C; p.F218S) in peroxisomal biogenesis factor 5 (PEX5), a peroxisome import receptor protein. This missense mutation was confirmed by bidirectional Sanger sequencing. It segregated with the disease phenotype in the family and was absent in ethnically matched control chromosomes. The lens-specific knockout mice of Pex5 recapitulated the cataractous phenotype. In vitro import assays revealed a normal capacity of the mutant PEX5 to enter the peroxisomal Docking/Translocation Module (DTM) in the presence of peroxisome targeting signal 1 (PTS1) cargo protein, be monoubiquitinated and exported back into the cytosol. Importantly, the mutant PEX5 protein was unable to form a stable trimeric complex with peroxisomal biogenesis factor 7 (PEX7) and a peroxisome targeting signal 2 (PTS2) cargo protein and, therefore, failed to promote the import of PTS2 cargo proteins into peroxisomes. In conclusion, we report a novel missense mutation in PEX5 responsible for the defective import of PTS2 cargo proteins into peroxisomes resulting in congenital cataracts and developmental defects.
AB - Peroxisomes, single-membrane intracellular organelles, play an important role in various metabolic pathways. The translocation of proteins from the cytosol to peroxisomes depends on peroxisome import receptor proteins and defects in peroxisome transport result in a wide spectrum of peroxisomal disorders. Here, we report a large consanguineous family with autosomal recessive congenital cataracts and developmental defects. Genome-wide linkage analysis localized the critical interval to chromosome 12p with a maximum two-point LOD score of 4.2 (θ = 0). Next-generation exome sequencing identified a novel homozygous missense variant (c.653 T > C; p.F218S) in peroxisomal biogenesis factor 5 (PEX5), a peroxisome import receptor protein. This missense mutation was confirmed by bidirectional Sanger sequencing. It segregated with the disease phenotype in the family and was absent in ethnically matched control chromosomes. The lens-specific knockout mice of Pex5 recapitulated the cataractous phenotype. In vitro import assays revealed a normal capacity of the mutant PEX5 to enter the peroxisomal Docking/Translocation Module (DTM) in the presence of peroxisome targeting signal 1 (PTS1) cargo protein, be monoubiquitinated and exported back into the cytosol. Importantly, the mutant PEX5 protein was unable to form a stable trimeric complex with peroxisomal biogenesis factor 7 (PEX7) and a peroxisome targeting signal 2 (PTS2) cargo protein and, therefore, failed to promote the import of PTS2 cargo proteins into peroxisomes. In conclusion, we report a novel missense mutation in PEX5 responsible for the defective import of PTS2 cargo proteins into peroxisomes resulting in congenital cataracts and developmental defects.
UR - http://www.scopus.com/inward/record.url?scp=85098511203&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85098511203&partnerID=8YFLogxK
U2 - 10.1007/s00439-020-02238-z
DO - 10.1007/s00439-020-02238-z
M3 - Article
C2 - 33389129
AN - SCOPUS:85098511203
SN - 0340-6717
VL - 140
SP - 649
EP - 666
JO - Human genetics
JF - Human genetics
IS - 4
ER -