| 1. |
- Friedman, James S., et al.
(författare)
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Mutations in a BTB-Kelch Protein, KLHL7, Cause Autosomal-Dominant Retinitis Pigmentosa
- 2009
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Ingår i: American Journal of Human Genetics. - : Elsevier BV. - 0002-9297. ; 84:6, s. 792-800
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Tidskriftsartikel (refereegranskat)abstract
- Retinitis pigmentosa (RP) refers to a genetically heterogeneous group of progressive neurodegenerative diseases that result in dysfunction and/or death of rod and cone photoreceptors in the retina. So far, 18 genes have been identified for autosomal-dominant (ad) RP. Here, we describe an adRP locus (RP42) at chromosome 7p15 through linkage analysis in a six-generation Scandinavian family and identify a disease-causing mutation, c.449G -> A (p.S150N), in exon 6 of the KLHL7 gene. Mutation screening of KLHL7 in 502 retinopathy probands has revealed three different missense mutations in six independent families. KLHL7 is widely expressed, including expression in rod photoreceptors, and encodes a 75 kDa protein of the BTB-Kelch Subfamily within the BTB superfamily. BTB-Kelch proteins have been implicated in ubiquitination through Cullin E3 ligases. Notably, all three putative disease-causing KLHL7 mutations are within a conserved BACK domain; homology modeling suggests that mutant amino acid side chains can potentially fill the cleft between two helices, thereby affecting the ubiquitination complexes. Mutations in an identical region of another BTB-Kelch protein, gigaxonin, have previously been associated with giant axonal neuropathy. Our studies suggest an additional role of the ubiquitin-proteasome protein-degradation pathway in maintaining neuronal health and in disease.
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| 2. |
- Friedman, James S., et al.
(författare)
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Premature truncation of a novel protein, RD3, exhibiting subnuclear localization is associated with retinal degeneration
- 2006
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Ingår i: American Journal of Human Genetics. - 0002-9297. ; 79:6, s. 1059-1070
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Tidskriftsartikel (refereegranskat)abstract
- The rd3 mouse is one of the oldest identified models of early-onset retinal degeneration. Using the positional candidate approach, we have identified a C -> T substitution in a novel gene, Rd3, that encodes an evolutionarily conserved protein of 195 amino acids. The rd3 mutation results in a predicted stop codon after residue 106. This change is observed in four rd3 lines derived from the original collected mice but not in the nine wild-type mouse strains that were examined. Rd3 is preferentially expressed in the retina and exhibits increasing expression through early postnatal development. In transiently transfected COS-1 cells, the RD3-fusion protein shows subnuclear localization adjacent to promyelocytic leukemia-gene-product bodies. The truncated mutant RD3 protein is detectable in COS-1 cells but appears to get degraded rapidly. To explore potential association of the human RD3 gene at chromosome 1q32 with retinopathies, we performed a mutation screen of 881 probands from North America, India, and Europe. In addition to several alterations of uncertain significance, we identified a homozygous alteration in the invariant G nucleotide of the RD3 exon 2 donor splice site in two siblings with Leber congenital amaurosis. This mutation is predicted to result in premature truncation of the RD3 protein, segregates with the disease, and is not detected in 121 ethnically matched control individuals. We suggest that the retinopathy-associated RD3 protein is part of subnuclear protein complexes involved in diverse processes, such as transcription and splicing.
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| 3. |
- Bujakowska, Kinga, et al.
(författare)
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Study of Gene-Targeted Mouse Models of Splicing Factor Gene Prpf31 Implicated in Human Autosomal Dominant Retinitis Pigmentosa (RP)
- 2009
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Ingår i: Investigative Ophthalmology & Visual Science. - : Association for Research in Vision and Ophthalmology (ARVO). - 1552-5783. ; 50:12, s. 5927-5933
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE. Pre-mRNA processing factor 31 (PRPF31) is a ubiquitous protein needed for the assembly of the pre-mRNA splicing machinery. It has been shown that mutations in this gene cause autosomal dominant retinitis pigmentosa 11 (RP11), which is characterized by rod-cell degeneration. Interestingly, mutations in this ubiquitously expressed gene do not lead to phenotypes other than retinal malfunction. Furthermore, the dominant inheritance pattern has shown incomplete penetrance, which poses interesting questions about the disease mechanism of RP11. METHODS. To characterize PRPF31 function in the rod cells, two animal models have been generated. One was a heterozygous knock-in mouse (Prpf31(A216P/+)) carrying a point mutation p.A216P, which has previously been identified in RP11 patients. The second was a heterozygous knockout mouse (Prpf31(+/-)). Retinal degeneration in RP11 mouse models was monitored by electroretinography and histology. RESULTS. Generation of the mouse models is presented, as are results of ERGs and retinal morphology. No degenerative phenotype on fundus examination was found in Prpf31(A216P/+) and Prpf31(+/-) mice. Prpf31(A216P/A216P) and Prpf31(-/-) genotypes were embryonic lethal. CONCLUSIONS. The results imply that Prpf31 is necessary for survival, and there is no compensation mechanism in mouse for the lack of this splicing factor. The authors suggest that p.A216P mutation in Prpf31 does not exert a dominant negative effect and that one Prpf31 wild-type allele is sufficient for maintenance of the healthy retina in mice.
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| 4. |
- Lehmann, Ordan J, et al.
(författare)
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Fox's in development and disease.
- 2003
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Ingår i: Trends in genetics : TIG. - 0168-9525. ; 19:6, s. 339-44
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Forskningsöversikt (refereegranskat)abstract
- Since the first forkhead (Fox) gene was identified, the importance of this family of transcription factors has increased steadily with the discoveries of the diverse range of developmental processes that they regulate in eukaryotes. Among other processes, the Fox factors are important in the establishment of the body axis and the development of tissues from all three germ layers. In this article, we present some of the recent data on this gene family with reference to selected phenotypes observed in patients and model organisms, and the sensitivity of developmental processes to alterations in forkhead gene dosage.
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