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Ruiz-Matos SJ, Ruiz-Justiz AJ, Izquierdo N. Retinitis Pigmentosa Sine Pigmento in a Patient With a Heterozygous Mutation on the KIF7 Gene: A Case Report. Cureus 2024; 16:e62689. [PMID: 39036105 PMCID: PMC11259021 DOI: 10.7759/cureus.62689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/19/2024] [Indexed: 07/23/2024] Open
Abstract
Mutations in the KIF7 gene have been implicated in autosomal recessive conditions such as Joubert syndrome, acrocallosal syndrome, and fetal hydrolethalus, as well as in retinal degeneration and other ocular manifestations due to their effect on primary cilia. In this study, we report that the full-field electroretinogram (ERG) test showed non-recordable scotopic ERG responses, while photopic ERG responses were diminished bilaterally. This is a case report of a 62-year-old female patient with painless, progressive vision loss in both eyes. Fundus examination revealed a pale optic nerve head, vessel attenuation, and macular thinning without peripheral pigmentary changes. The full-field electroretinogram (ERG) test showed non-recordable scotopic ERG responses, while photopic ERG responses were diminished bilaterally. Based on these ocular findings, the patient was clinically diagnosed with retinitis pigmentosa (RP) sine pigmento. Genetic testing identified a pathogenic heterozygous mutation in the KIF7 gene with the variant c.61C>T (p.Arg21*). Our case suggests that this pathologic variant may be associated with RP sine pigmento. Further studies are warranted to better understand the role of the KIF7 gene in retinal dystrophies.
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Affiliation(s)
- Sebastián J Ruiz-Matos
- Department of Ophthalmology, University of Puerto Rico, Medical Sciences Campus, San Juan, PRI
| | - Armando J Ruiz-Justiz
- Department of Ophthalmology, University of Puerto Rico, Medical Sciences Campus, San Juan, PRI
| | - Natalio Izquierdo
- Department of Surgery, School of Medicine, University of Puerto Rico, Medical Sciences Campus, San Juan, PRI
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Blasius TL, Yue Y, Prasad R, Liu X, Gennerich A, Verhey KJ. Sequences in the stalk domain regulate auto-inhibition and ciliary tip localization of the immotile kinesin-4 KIF7. J Cell Sci 2021; 134:269104. [PMID: 34114033 DOI: 10.1242/jcs.258464] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 05/27/2021] [Indexed: 12/31/2022] Open
Abstract
The kinesin-4 member KIF7 plays critical roles in Hedgehog signaling in vertebrate cells. KIF7 is an atypical kinesin as it binds to microtubules but is immotile. We demonstrate that, like conventional kinesins, KIF7 is regulated by auto-inhibition, as the full-length protein is inactive for microtubule binding in cells. We identify a segment, the inhibitory coiled coil (inhCC), that is required for auto-inhibition of KIF7, whereas the adjacent regulatory coiled coil (rCC) that contributes to auto-inhibition of the motile kinesin-4s KIF21A and KIF21B is not sufficient for KIF7 auto-inhibition. Disease-associated mutations in the inhCC relieve auto-inhibition and result in strong microtubule binding. Surprisingly, uninhibited KIF7 proteins did not bind preferentially to or track the plus ends of growing microtubules in cells, as suggested by previous in vitro work, but rather bound along cytosolic and axonemal microtubules. Localization to the tip of the primary cilium also required the inhCC, and could be increased by disease-associated mutations regardless of the auto-inhibition state of the protein. These findings suggest that loss of KIF7 auto-inhibition and/or altered cilium tip localization can contribute to the pathogenesis of human disease.
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Affiliation(s)
- T Lynne Blasius
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Yang Yue
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - RaghuRam Prasad
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Xinglei Liu
- Department of Anatomy and Structural Biology and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Arne Gennerich
- Department of Anatomy and Structural Biology and Gruss-Lipper Biophotonics Center, Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Kristen J Verhey
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
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McKnight I, Hart C, Park IH, Shim JW. Genes causing congenital hydrocephalus: Their chromosomal characteristics of telomere proximity and DNA compositions. Exp Neurol 2021; 335:113523. [PMID: 33157092 PMCID: PMC7750280 DOI: 10.1016/j.expneurol.2020.113523] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 10/10/2020] [Accepted: 10/30/2020] [Indexed: 01/06/2023]
Abstract
Congenital hydrocephalus (CH) is caused by genetic mutations, but whether factors impacting human genetic mutations are disease-specific remains elusive. Given two factors associated with high mutation rates, we reviewed how many disease-susceptible genes match with (i) proximity to telomeres or (ii) high adenine and thymine (A + T) content in human CH as compared to other disorders of the central nervous system (CNS). We extracted genomic information using a genome data viewer. Importantly, 98 of 108 genes causing CH satisfied (i) or (ii), resulting in >90% matching rate. However, such a high accordance no longer sustained as we checked two factors in Alzheimer's disease (AD) and/or familial Parkinson's disease (fPD), resulting in 84% and 59% matching, respectively. A disease-specific matching of telomere proximity or high A + T content predicts causative genes of CH much better than neurodegenerative diseases and other CNS conditions, likely due to sufficient number of known causative genes (n = 108) and precise determination and classification of the genotype and phenotype. Our analysis suggests a need for identifying genetic basis of both factors before human clinical studies, to prioritize putative genes found in preclinical models into the likely (meeting at least one) and more likely candidate (meeting both), which predisposes human genes to mutations.
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Affiliation(s)
- Ian McKnight
- Department of Biomedical Engineering, Marshall University, Huntington, WV 25755, USA
| | - Christoph Hart
- Department of Biomedical Engineering, Marshall University, Huntington, WV 25755, USA
| | - In-Hyun Park
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06519, USA
| | - Joon W Shim
- Department of Biomedical Engineering, Marshall University, Huntington, WV 25755, USA.
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Niceta M, Dentici ML, Ciolfi A, Marini R, Barresi S, Lepri FR, Novelli A, Bertini E, Cappa M, Digilio MC, Dallapiccola B, Tartaglia M. Co-occurrence of mutations in KIF7 and KIAA0556 in Joubert syndrome with ocular coloboma, pituitary malformation and growth hormone deficiency: a case report and literature review. BMC Pediatr 2020; 20:120. [PMID: 32164589 PMCID: PMC7066839 DOI: 10.1186/s12887-020-2019-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 03/02/2020] [Indexed: 12/13/2022] Open
Abstract
Background Joubert syndrome is a recessive neurodevelopmental disorder characterized by clinical and genetic heterogeneity. Clinical hallmarks include hypotonia, ataxia, facial dysmorphism, abnormal eye movement, irregular breathing pattern cognitive impairment and, the molar tooth sign is the pathognomonic midbrain-hindbrain malformation on magnetic resonance imaging. The disorder is predominantly caused by biallelic mutations in more than 30 genes encoding proteins with a pivotal role in morphology and function of the primary cilium. Oligogenic inheritance or occurrence of genetic modifiers has been suggested to contribute to the variability of the clinical phenotype. We report on a family with peculiar clinical spectrum Joubert syndrome molecularly and clinically dissecting a complex phenotype, in which hypogonadism, pituitary malformation and growth hormone deficiency occur as major features. Case presentation A 7 year-old male was enrolled in a dedicated “Undiagnosed Patients Program” for a peculiar form of Joubert syndrome complicated by iris and retinochoroidal coloboma, hypogonadism pituitary malformation, and growth hormone deficiency. The molecular basis of the complex phenotype was investigated by whole exome sequencing. The concomitant occurrence of homozygosity for mutations in KIF7 and KIAA0556 was identified, and the assessment of major clinical features associated with mutations in these two genes provided evidence that these two independent events represent the cause underlying the complexity of the present clinical phenotype. Conclusion Beside the clinical variability of Joubert syndrome, co-occurrence of mutations in ciliopathy-associated genes may contribute to increase the clinical complexity of the trait.
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Affiliation(s)
- Marcello Niceta
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy.
| | - Maria Lisa Dentici
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Andrea Ciolfi
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Romana Marini
- Unit of Endocrinology, Academic Department of Pediatrics, Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Sabina Barresi
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Francesca Romana Lepri
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Antonio Novelli
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Enrico Bertini
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Marco Cappa
- Unit of Endocrinology, Academic Department of Pediatrics, Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Maria Cristina Digilio
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Bruno Dallapiccola
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Ospedale Pediatrico Bambino Gesù, IRCCS, Viale di San Paolo 15, 00146, Rome, Italy
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Massa F, Tammaro R, Prado MA, Cesana M, Lee BH, Finley D, Franco B, Morleo M. The deubiquitinating enzyme Usp14 controls ciliogenesis and Hedgehog signaling. Hum Mol Genet 2020; 28:764-777. [PMID: 30388222 DOI: 10.1093/hmg/ddy380] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 10/11/2018] [Accepted: 10/16/2018] [Indexed: 12/20/2022] Open
Abstract
Primary cilia are hair-like organelles that play crucial roles in vertebrate development, organogenesis and when dysfunctional result in pleiotropic human genetic disorders called ciliopathies, characterized by overlapping phenotypes, such as renal and hepatic cysts, skeletal defects, retinal degeneration and central nervous system malformations. Primary cilia act as communication hubs to transfer extracellular signals into intracellular responses and are essential for Hedgehog (Hh) signal transduction in mammals. Despite the renewed interest in this ancient organelle of growing biomedical importance, the molecular mechanisms that trigger cilia formation, extension and ciliary signal transduction are still not fully understood. Here we provide, for the first time, evidence that the deubiquitinase ubiquitin-specific protease-14 (Usp14), a major regulator of the ubiquitin proteasome system (UPS), controls ciliogenesis, cilia elongation and Hh signal transduction. Moreover, we show that pharmacological inhibition of Usp14 positively affects Hh signal transduction in a model of autosomal dominant polycystic kidney disease. These findings provide new insight into the spectrum of action of UPS in cilia biology and may provide novel opportunities for therapeutic intervention in human conditions associated with ciliary dysfunction.
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Affiliation(s)
- Filomena Massa
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, Pozzuoli, Naples, Italy
| | - Roberta Tammaro
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, Pozzuoli, Naples, Italy
| | - Miguel A Prado
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Marcella Cesana
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, Pozzuoli, Naples, Italy
| | - Byung-Hoon Lee
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA.,Department of New Biology, Daegu Gyeongbuk Institute of Science and Technology, Daegu, Korea
| | - Daniel Finley
- Department of Cell Biology, Harvard Medical School, Boston, MA, USA
| | - Brunella Franco
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, Pozzuoli, Naples, Italy.,Medical Genetics, Department of Translational Medicine, University of Naples Federico II, Via Sergio Pansini 5, Naples, Italy
| | - Manuela Morleo
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, Pozzuoli, Naples, Italy.,Medical Genetics, Department of Translational Medicine, University of Naples Federico II, Via Sergio Pansini 5, Naples, Italy
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Maerz LD, Casar Tena T, Gerhards J, Donow C, Jeggo PA, Philipp M. Analysis of cilia dysfunction phenotypes in zebrafish embryos depleted of Origin recognition complex factors. Eur J Hum Genet 2019; 27:772-782. [PMID: 30696958 DOI: 10.1038/s41431-019-0338-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 12/26/2018] [Accepted: 01/04/2019] [Indexed: 12/15/2022] Open
Abstract
Meier-Gorlin syndrome (MGS) is a rare, congenital primordial microcephalic dwarfism disorder. MGS is caused by genetic variants of components of the origin recognition complex (ORC) consisting of ORC1-6 and the pre-replication complex, which together enable origin firing and hence genome replication. In addition, ORC1 has previously been shown to play a role in ciliogenesis. Here, we extend this work and investigate the function of ORC1 and two other members of the complex on cilia at an organismal level. Knockdown experiments in zebrafish confirmed the impact of ORC1 on cilia. ORC1-deficiency confers defects anticipated to arise from impaired cilia function such as formation of oedema, kidney cysts, curved bodies and left-right asymmetry defects. We found ORC1 furthermore required for cilium formation in zebrafish and demonstrate that ciliopathy phenotypes in ORC1-depleted zebrafish could not be rescued by reconstitution with ORC1 bearing a genetic variant previously identified in MGS patients. Loss-of-function of Orc4 and Orc6, respectively, conferred similar ciliopathy phenotypes and cilium shortening in zebrafish, suggesting that several, if not all, components of the ORC regulate ciliogenesis downstream to or in addition to their canonical function in replication initiation. This study presents the first in vivo evidence of an influence of the MGS genes of the ORC family on cilia, and consolidates the possibility that cilia dysfunction could contribute to the clinical manifestation of ORC-deficient MGS.
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Affiliation(s)
- Lars D Maerz
- Institute of Biochemistry and Molecular Biology, Ulm University, 89081, Ulm, Germany
| | - Teresa Casar Tena
- Institute of Biochemistry and Molecular Biology, Ulm University, 89081, Ulm, Germany
| | - Julian Gerhards
- Institute of Biochemistry and Molecular Biology, Ulm University, 89081, Ulm, Germany
| | - Cornelia Donow
- Institute of Biochemistry and Molecular Biology, Ulm University, 89081, Ulm, Germany
| | - Penelope A Jeggo
- Genome Damage and Stability Centre, University of Sussex, Brighton, BN1 9RQ, UK
| | - Melanie Philipp
- Institute of Biochemistry and Molecular Biology, Ulm University, 89081, Ulm, Germany.
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Loss of the neurodevelopmental Joubert syndrome causing protein, Ahi1, causes motor and muscle development delays independent of central nervous system involvement. Dev Biol 2019; 448:36-47. [PMID: 30695685 DOI: 10.1016/j.ydbio.2019.01.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 01/25/2019] [Accepted: 01/25/2019] [Indexed: 12/15/2022]
Abstract
Joubert syndrome (JBTS) is a predominantly autosomal recessive neurodevelopmental disorder that presents with characteristic malformations of the cerebellar vermis, superior cerebellar peduncles and midbrain in humans. Accompanying these malformations are a heterogeneous set of clinical symptoms, which frequently include deficits in motor and muscle function, such as hypotonia (low muscle tone) and ataxia (clumsiness). These symptoms are attributed to improper development of the hindbrain, but no direct evidence has been reported linking these in JBTS. Here, we describe muscle developmental defects in a mouse with a targeted deletion of the Abelson helper integration site 1 gene, Ahi1, one of the genes known to cause JBTS in humans. While FVB/NJ Ahi1-/- mice display no gross malformations of the cerebellum, deficits are observed in several measures of motor function, strength, and body development. Specifically, Ahi1-/- mice show delayed physical development, delays in surface reflex righting as neonates, and reductions in grip strength and spontaneous locomotor activity as adults. Additionally, Ahi1-/- mice showed evidence of muscle-specific contributions to this phenotype, such as reductions in 1) myoblast differentiation potential in vitro, 2) muscle desmin expression, and 3) overall muscle mass, myonuclear domain, and muscle fiber cross-sectional area. Together, these data suggest that loss of Ahi1 may cause abnormalities in the differentiation of myoblasts to mature muscle cells. Moreover, Ahi1 loss impacts muscle development directly, outside of any indirect impact of cerebellar malformations, revealing a novel myogenic cause for hypotonia in JBTS.
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Bozal-Basterra L, Martín-Ruíz I, Pirone L, Liang Y, Sigurðsson JO, Gonzalez-Santamarta M, Giordano I, Gabicagogeascoa E, de Luca A, Rodríguez JA, Wilkie AO, Kohlhase J, Eastwood D, Yale C, Olsen JV, Rauchman M, Anderson KV, Sutherland JD, Barrio R. Truncated SALL1 Impedes Primary Cilia Function in Townes-Brocks Syndrome. Am J Hum Genet 2018; 102:249-265. [PMID: 29395072 PMCID: PMC5985538 DOI: 10.1016/j.ajhg.2017.12.017] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 12/19/2017] [Indexed: 12/21/2022] Open
Abstract
Townes-Brocks syndrome (TBS) is characterized by a spectrum of malformations in the digits, ears, and kidneys. These anomalies overlap those seen in a growing number of ciliopathies, which are genetic syndromes linked to defects in the formation or function of the primary cilia. TBS is caused by mutations in the gene encoding the transcriptional repressor SALL1 and is associated with the presence of a truncated protein that localizes to the cytoplasm. Here, we provide evidence that SALL1 mutations might cause TBS by means beyond its transcriptional capacity. By using proximity proteomics, we show that truncated SALL1 interacts with factors related to cilia function, including the negative regulators of ciliogenesis CCP110 and CEP97. This most likely contributes to more frequent cilia formation in TBS-derived fibroblasts, as well as in a CRISPR/Cas9-generated model cell line and in TBS-modeled mouse embryonic fibroblasts, than in wild-type controls. Furthermore, TBS-like cells show changes in cilia length and disassembly rates in combination with aberrant SHH signaling transduction. These findings support the hypothesis that aberrations in primary cilia and SHH signaling are contributing factors in TBS phenotypes, representing a paradigm shift in understanding TBS etiology. These results open possibilities for the treatment of TBS.
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He M, Agbu S, Anderson KV. Microtubule Motors Drive Hedgehog Signaling in Primary Cilia. Trends Cell Biol 2017; 27:110-125. [PMID: 27765513 PMCID: PMC5258846 DOI: 10.1016/j.tcb.2016.09.010] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 09/08/2016] [Accepted: 09/23/2016] [Indexed: 01/05/2023]
Abstract
The mammalian Hedgehog (Hh) signaling pathway is required for development and for maintenance of adult stem cells, and overactivation of the pathway can cause tumorigenesis. All responses to Hh family ligands in mammals require the primary cilium, an ancient microtubule-based organelle that extends from the cell surface. Genetic studies in mice and humans have defined specific functions for cilium-associated microtubule motor proteins: they act in the construction and disassembly of the primary cilium, they control ciliary length and stability, and some have direct roles in mammalian Hh signal transduction. These studies highlight how integrated genetic and cell biological studies can define the molecular mechanisms that underlie cilium-associated health and disease.
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Affiliation(s)
- Mu He
- Department of Physiology and Department of Biochemistry and Biophysics, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Stephanie Agbu
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA; Biochemistry, Cell, and Molecular Biology Program, Weill Graduate School of Medical Sciences of Cornell University, 1300 York Avenue, New York, NY 10065, USA
| | - Kathryn V Anderson
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
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