Cranio-lenticulo-sutural dysplasia is caused by a SEC23A mutation leading to abnormal endoplasmic-reticulum-to-Golgi trafficking.
Cranio-lenticulo-sutural dysplasia (CLSD) is an autosomal recessive syndrome characterized by late-closing fontanels, sutural cataracts, facial dysmorphisms and skeletal defects mapped to chromosome 14q13-q21 (ref. 1). Here we show, using a positional cloning approach, that an F382L amino acid substitution in SEC23A segregates with this syndrome. SEC23A is an essential component of the COPII-coated vesicles that transport secretory proteins from the endoplasmic reticulum to the Golgi complex. Electron microscopy and immunofluorescence show that there is gross dilatation of the endoplasmic reticulum in fibroblasts from individuals affected with CLSD. These cells also exhibit cytoplasmic mislocalization of SEC31. Cell-free vesicle budding assays show that the F382L substitution results in loss of SEC23A function. A phenotype reminiscent of CLSD is observed in zebrafish embryos injected with sec23a-blocking morpholinos. Our observations suggest that disrupted endoplasmic reticulum export of the secretory proteins required for normal morphogenesis accounts for CLSD.
Boyadjiev
Simeon A
SA
McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA. simeon.boyd@ucdmc.ucdavis.edu
Fromme
J Christopher
JC
Ben
Jin
J
Chong
Samuel S
SS
Nauta
Christopher
C
Hur
David J
DJ
Zhang
George
G
Hamamoto
Susan
S
Schekman
Randy
R
Ravazzola
Mariella
M
Orci
Lelio
L
Eyaid
Wafaa
W
D000015:Abnormalities, Multiple / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D002386:Cataract / Q000235:genetics; D004195:Disease Models, Animal; D004625:Embryo, Nonmammalian; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005147:Facial Bones / Q000002:abnormalities; D005260:Female; D006056:Golgi Apparatus / Q000378:metabolism*; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation; D010375:Pedigree; D021381:Protein Transport / Q000235:genetics; D033921:Vesicular Transport Proteins / Q000235:genetics* / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism
C512739:SEC23A protein, human; D033921:Vesicular Transport Proteins; D029961:Zebrafish Proteins