Dataset Information

Geleophysic dysplasia: novel missense variants and insights into ADAMTSL2 intracellular trafficking.

ABSTRACT: Geleophysic dysplasia (GPHYSD1, MIM231050; GPHYSD2, MIM614185; GPHYSD3, MIM617809) is an autosomal disorder characterized by short-limb dwarfism, brachydactyly, cardiac valvular disease, and laryngotracheal stenosis. Mutations in ADAMTSL2, FBN1, and LTBP3 genes are responsible for this condition. We found that three previously described cases of GPHYSD diagnosed clinically were homozygote or compound heterozygotes for five ADAMTSL2 variants, four of which not being previously reported. By electron microscopy, skin fibroblasts available in one case homozygote for an ADAMTSL2 variant showed a defective intracellular localization of mutant ADAMTSL2 protein that did not accumulate within lysosome-like intra-cytoplasmic inclusions. Moreover, this mutant ADAMTSL2 protein was less secreted in medium and resulted in increased SMAD2 phosphorylation in transfected HEK293 cells.

SUBMITTER: Piccolo P

PROVIDER: S-EPMC6732760 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Geleophysic dysplasia: novel missense variants and insights into ADAMTSL2 intracellular trafficking.

Piccolo Pasquale P Sabatino Valeria V Mithbaokar Pratibha P Polishchuck Elena E Law Simon K SK Magraner-Pardo Lorena L Pons Tirso T Polishchuck Roman R Brunetti-Pierri Nicola N

Molecular genetics and metabolism reports 20190905

Geleophysic dysplasia (GPHYSD1, MIM231050; GPHYSD2, MIM614185; GPHYSD3, MIM617809) is an autosomal disorder characterized by short-limb dwarfism, brachydactyly, cardiac valvular disease, and laryngotracheal stenosis. Mutations in ADAMTSL2, FBN1, and LTBP3 genes are responsible for this condition. We found that three previously described cases of GPHYSD diagnosed clinically were homozygote or compound heterozygotes for five ADAMTSL2 variants, four of which not being pr ...[more]

PMID: 31516831

Similar Datasets

Project description:Mutations in the secreted glycoprotein ADAMTSL2 cause recessive geleophysic dysplasia (GD) in humans and Musladin-Lueke syndrome (MLS) in dogs. GD is a severe, often lethal, condition presenting with short stature, brachydactyly, stiff skin, joint contractures, tracheal-bronchial stenosis and cardiac valve anomalies, whereas MLS is non-lethal and characterized by short stature and severe skin fibrosis. Although most mutations in fibrillin-1 (FBN1) cause Marfan syndrome (MFS), a microfibril disorder leading to transforming growth factor-? (TGF?) dysregulation, domain-specific FBN1 mutations result in dominant GD. ADAMTSL2 has been previously shown to bind FBN1 and latent TGF?-binding protein-1 (LTBP1). Here, we investigated mice with targeted Adamtsl2 inactivation as a new model for GD (Adamtsl2(-/-) mice). An intragenic lacZ reporter in these mice showed that ADAMTSL2 was produced exclusively by bronchial smooth muscle cells during embryonic lung development. Adamtsl2(-/-) mice, which died at birth, had severe bronchial epithelial dysplasia with abnormal glycogen-rich inclusions in bronchial epithelium resembling the cellular anomalies described previously in GD. An increase in microfibrils in the bronchial wall was associated with increased FBN2 and microfibril-associated glycoprotein-1 (MAGP1) staining, whereas LTBP1 staining was increased in bronchial epithelium. ADAMTSL2 was shown to bind directly to FBN2 with an affinity comparable to FBN1. The observed extracellular matrix (ECM) alterations were associated with increased bronchial epithelial TGF? signaling at 17.5 days of gestation; however, treatment with TGF?-neutralizing antibody did not correct the epithelial dysplasia. These investigations reveal a new function of ADAMTSL2 in modulating microfibril formation, and a previously unsuspected association with FBN2. Our studies suggest that the bronchial epithelial dysplasia accompanying microfibril dysregulation in Adamtsl2(-/-) mice cannot be reversed by TGF? neutralization, and thus might be mediated by other mechanisms.

Project description:A disintegrin-like and metalloprotease domain with thrombospondin type 1 repeats-like 2 (ADAMTSL2) is a matricellular protein that interacts with latent TGF-b binding protein 1 and fibrillin-1. ADAMTSL2 mutations cause an autosomal recessive connective tissue disorder named geleophysic dysplasia 1 (GPHYSD1, OMIM #231050), which is characterized by short stature, small hands and feet, and cardiac defects. ADAMTSL2 contains seven thrombospondin type-1 repeats (TSRs), six of which contain the consensus sequence for serine or threonine glycosylation by protein O-fucosyltransferase 2 (POFUT2). O-fucose modified TSRs are subsequently elongated to a Glucose1-3Fucose (GlcFuc) disaccharide by b3-glucosyltransferase (B3GLCT). B3GLCT mutations cause Peters Plus Syndrome (PTRPLS, OMIM #261540), which is characterized by skeletal defects similar to those of GPHYSD1. Several ADAMTSL2 TSRs have consensus sequences for C-mannosylation, and one TSR contains a sequon for N-glycosylation that overlaps with an O-fucosylation site. Six reported GPHYSD1 mutations occur within the TSRs and two lie near O-fucosylation sites. To investigate the effects of TSR glycosylation on ADAMTSL2 function, we used mass spectrometry to identify glycan modifications at the predicted consensus sequences. We found that most TSRs were modified with the GlcFuc disaccharide at high stoichiometry at O-fucosylation sites and variable mannose stoichiometry at C-mannosylation sites. Loss of ADAMTSL2 secretion in POFUT2 knockout but not in B3GLCT knockout cells suggested that impaired ADAMTSL2 secretion is not responsible for skeletal defects in PTRPLS patients lacking B3GLCT. In contrast, secretion of mouse ADAMTSL2 carrying GPHYSD1 mutations (S641L in TSR3 and G817R in TSR6) was significantly reduced in HEK293T cells. Moreover, S641L eliminated O-fucosylation of TSR3. Combined these results provide strong evidence that developmental abnormalities in GPHYSD1 patients with this mutation are caused by loss of O-fucosylation on TSR3 and impaired ADAMTSL2 secretion.

Project description:Introduction: Natriuretic peptide receptor 2 (NPR2 or NPR-B) plays a central role in growth development and bone morphogenesis and therefore loss-of-function variations in NPR2 gene have been reported to cause Acromesomelic Dysplasia, Maroteaux type 1 and short stature. While several hypotheses have been proposed to underlie the pathogenic mechanisms responsible for these conditions, the exact mechanisms, and functional characteristics of many of those variants and their correlations with the clinical manifestations have not been fully established. Methods: In this study, we examined eight NPR2 genetic missense variants (p.Leu51Pro, p.Gly123Val, p.Leu314Arg, p.Arg318Gly, p.Arg388Gln, p.Arg495Cys, p.Arg557His, and p.Arg932Cys) Acromesomelic Dysplasia, Maroteaux type 1 and short stature located on diverse domains and broadly classified as variants of uncertain significance. The evaluated variants are either reported in patients with acromesomelic dysplasia in the homozygous state or short stature in the heterozygous state. Our investigation included the evaluation of their expression, subcellular trafficking and localization, N-glycosylation profiles, and cyclic guanosine monophosphate (cGMP) production activity. Results and Discussion: Our results indicate that variants p.Leu51Pro, p.Gly123Val, p.Leu314Arg, p.Arg388Gln have defective cellular trafficking, being sequestered within the endoplasmic reticulum (ER), and consequently impaired cGMP production ability. Conversely, variants p.Arg318Gly, p.Arg495Cys, and p.Arg557His seem to display a non-statistically significant behavior that is slightly comparable to WT-NPR2. On the other hand, p.Arg932Cys which is located within the guanylyl cyclase active site displayed normal cellular trafficking profile albeit with defective cGMP. Collectively, our data highlights the genotype-phenotype relationship that might be responsible for the milder symptoms observed in short stature compared to acromesomelic dysplasia. This study enhances our understanding of the functional consequences of several NPR2 variants, shedding light on their mechanisms and roles in related genetic disorders which might also help in their pathogenicity re-classification.

Dataset Information

Geleophysic dysplasia: novel missense variants and insights into ADAMTSL2 intracellular trafficking.

Publications

Geleophysic dysplasia: novel missense variants and insights into ADAMTSL2 intracellular trafficking.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets