1
|
Aguila A, Salah S, Kulasekaran G, Shweiki M, Shaul-Lotan N, Mor-Shaked H, Daana M, Harel T, McPherson PS. A neurodevelopmental disorder associated with a loss-of-function missense mutation in RAB35. J Biol Chem 2024; 300:107124. [PMID: 38432637 PMCID: PMC10966776 DOI: 10.1016/j.jbc.2024.107124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 02/01/2024] [Accepted: 02/18/2024] [Indexed: 03/05/2024] Open
Abstract
Rab35 (Ras-associated binding protein) is a small GTPase that regulates endosomal membrane trafficking and functions in cell polarity, cytokinesis, and growth factor signaling. Altered Rab35 function contributes to progression of glioblastoma, defects in primary cilia formation, and altered cytokinesis. Here, we report a pediatric patient with global developmental delay, hydrocephalus, a Dandy-Walker malformation, axial hypotonia with peripheral hypertonia, visual problems, and conductive hearing impairment. Exome sequencing identified a homozygous missense variant in the GTPase fold of RAB35 (c.80G>A; p.R27H) as the most likely candidate. Functional analysis of the R27H-Rab35 variant protein revealed enhanced interaction with its guanine-nucleotide exchange factor, DENND1A and decreased interaction with a known effector, MICAL1, indicating that the protein is in an inactive conformation. Cellular expression of the variant drives the activation of Arf6, a small GTPase under negative regulatory control of Rab35. Importantly, variant expression leads to delayed cytokinesis and altered length, number, and Arl13b composition of primary cilia, known factors in neurodevelopmental disease. Our findings provide evidence of altered Rab35 function as a causative factor of a neurodevelopmental disorder.
Collapse
Affiliation(s)
- Adriana Aguila
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Somaya Salah
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel
| | - Gopinath Kulasekaran
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Moatasem Shweiki
- Neurosurgery Department, Hadassah Medical Center, Jerusalem, Israel
| | - Nava Shaul-Lotan
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel
| | - Hagar Mor-Shaked
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel; Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Muhannad Daana
- Child Development Centers, Clalit Health Care Services, Yokne'am Illit, Israel
| | - Tamar Harel
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel; Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Peter S McPherson
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada.
| |
Collapse
|
2
|
Abu-Libdeh B, Mor-Shaked H, Atawna AA, Gillis D, Halstuk O, Shaul-Lotan N, Slae M, Sultan M, Meiner V, Elpeleg O, Harel T. Homozygous variant in MADD, encoding a Rab guanine nucleotide exchange factor, results in pleiotropic effects and a multisystemic disorder. Eur J Hum Genet 2021; 29:977-987. [PMID: 33723354 DOI: 10.1038/s41431-021-00844-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 01/20/2021] [Accepted: 02/24/2021] [Indexed: 12/20/2022] Open
Abstract
Rab proteins coordinate inter-organellar vesicle-mediated transport, facilitating intracellular communication, protein recycling, and signaling processes. Dysfunction of Rab proteins or their direct interactors leads to a wide range of diseases with diverse manifestations. We describe seven individuals from four consanguineous Arab Muslim families with an infantile-lethal syndrome, including failure to thrive (FTT), chronic diarrhea, neonatal respiratory distress, variable pituitary dysfunction, and distal arthrogryposis. Exome sequencing analysis in the independent families, followed by an internal gene-matching process using a local exome database, identified a homozygous splice-site variant in MADD (c.2816 + 1 G > A) on a common haplotype. The variant segregated with the disease in all available family members. Determination of cDNA sequence verified single exon skipping, resulting in an out-of-frame deletion. MADD encodes a Rab guanine nucleotide exchange factor (GEF), which activates RAB3 and RAB27A/27B and is thus a crucial regulator of neuromuscular junctions and endocrine secretory granule release. Moreover, MADD protects cells from caspase-mediated TNF-α-induced apoptosis. The combined roles of MADD and its downstream effectors correlate with the phenotypic spectrum of disease, and call for additional studies to confirm the pathogenic mechanism and to investigate possible therapeutic avenues through modulation of TNF-α signaling.
Collapse
Affiliation(s)
- Bassam Abu-Libdeh
- Department of Pediatrics, Makassed Hospital and Faculty of Medicine, Al-Quds University, East Jerusalem, Palestine
| | - Hagar Mor-Shaked
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel.,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Amir A Atawna
- Department of Neonatology, Makassed Hospital, East Jerusalem, Palestine
| | - David Gillis
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Pediatrics, Hadassah Medical Center, Jerusalem, Israel
| | - Orli Halstuk
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel.,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Nava Shaul-Lotan
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel
| | - Mordechai Slae
- Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.,Department of Pediatrics, Hadassah Medical Center, Jerusalem, Israel
| | - Mutaz Sultan
- Department of Pediatrics, Makassed Hospital and Faculty of Medicine, Al-Quds University, East Jerusalem, Palestine
| | - Vardiella Meiner
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel.,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Orly Elpeleg
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel.,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Tamar Harel
- Department of Genetics, Hadassah Medical Center, Jerusalem, Israel. .,Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel.
| |
Collapse
|
3
|
Turnpenny PD, Wright MJ, Sloman M, Caswell R, van Essen AJ, Gerkes E, Pfundt R, White SM, Shaul-Lotan N, Carpenter L, Schaefer GB, Fryer A, Innes AM, Forbes KP, Chung WK, McLaughlin H, Henderson LB, Roberts AE, Heath KE, Paumard-Hernández B, Gener B, Fawcett KA, Gjergja-Juraški R, Pilz DT, Fry AE, Fry AE. Missense Mutations of the Pro65 Residue of PCGF2 Cause a Recognizable Syndrome Associated with Craniofacial, Neurological, Cardiovascular, and Skeletal Features. Am J Hum Genet 2018; 103:1054-1055. [PMID: 30526864 DOI: 10.1016/j.ajhg.2018.11.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
|
4
|
Turnpenny PD, Wright MJ, Sloman M, Caswell R, van Essen AJ, Gerkes E, Pfundt R, White SM, Shaul-Lotan N, Carpenter L, Schaefer GB, Fryer A, Innes AM, Forbes KP, Chung WK, McLaughlin H, Henderson LB, Roberts AE, Heath KE, Paumard-Hernández B, Gener B, Fawcett KA, Gjergja-Juraški R, Pilz DT, Fry AE, Fry AE. Missense Mutations of the Pro65 Residue of PCGF2 Cause a Recognizable Syndrome Associated with Craniofacial, Neurological, Cardiovascular, and Skeletal Features. Am J Hum Genet 2018; 103:786-793. [PMID: 30343942 DOI: 10.1016/j.ajhg.2018.09.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 09/22/2018] [Indexed: 12/15/2022] Open
Abstract
PCGF2 encodes the polycomb group ring finger 2 protein, a transcriptional repressor involved in cell proliferation, differentiation, and embryogenesis. PCGF2 is a component of the polycomb repressive complex 1 (PRC1), a multiprotein complex which controls gene silencing through histone modification and chromatin remodelling. We report the phenotypic characterization of 13 patients (11 unrelated individuals and a pair of monozygotic twins) with missense mutations in PCGF2. All the mutations affected the same highly conserved proline in PCGF2 and were de novo, excepting maternal mosaicism in one. The patients demonstrated a recognizable facial gestalt, intellectual disability, feeding problems, impaired growth, and a range of brain, cardiovascular, and skeletal abnormalities. Computer structural modeling suggests the substitutions alter an N-terminal loop of PCGF2 critical for histone biding. Mutant PCGF2 may have dominant-negative effects, sequestering PRC1 components into complexes that lack the ability to interact efficiently with histones. These findings demonstrate the important role of PCGF2 in human development and confirm that heterozygous substitutions of the Pro65 residue of PCGF2 cause a recognizable syndrome characterized by distinctive craniofacial, neurological, cardiovascular, and skeletal features.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Andrew E Fry
- Institute of Medical Genetics, University Hospital of Wales, Cardiff CF14 4XW, UK; Division of Cancer and Genetics, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK.
| |
Collapse
|