|
1
|
Nagy N, Pal M, Kun J, Galik B, Urban P, Medvecz M, Fabos B, Neller A, Abdolreza A, Danis J, Szabo V, Yang Z, Fenske S, Biel M, Gyenesei A, Adam E, Szell M. Missing Heritability in Albinism: Deep Characterization of a Hungarian Albinism Cohort Raises the Possibility of the Digenic Genetic Background of the Disease. Int J Mol Sci 2024; 25:1271. [PMID: 38279271 PMCID: PMC10817051 DOI: 10.3390/ijms25021271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 01/17/2024] [Accepted: 01/18/2024] [Indexed: 01/28/2024] Open
Abstract
Albinism is characterized by a variable degree of hypopigmentation affecting the skin and the hair, and causing ophthalmologic abnormalities. Its oculocutaneous, ocular and syndromic forms follow an autosomal or X-linked recessive mode of inheritance, and 22 disease-causing genes are implicated in their development. Our aim was to clarify the genetic background of a Hungarian albinism cohort. Using a 22-gene albinism panel, the genetic background of 11 of the 17 Hungarian patients was elucidated. In patients with unidentified genetic backgrounds (n = 6), whole exome sequencing was performed. Our investigations revealed a novel, previously unreported rare variant (N687S) of the two-pore channel two gene (TPCN2). The N687S variant of the encoded TPC2 protein is carried by a 15-year-old Hungarian male albinism patient and his clinically unaffected mother. Our segregational analysis and in vitro functional experiments suggest that the detected novel rare TPCN2 variant alone is not a disease-causing variant in albinism. Deep genetic analyses of the family revealed that the patient also carries a phenotype-modifying R305W variant of the OCA2 protein, and he is the only family member harboring this genotype. Our results raise the possibility that this digenic combination might contribute to the observed differences between the patient and the mother, and found the genetic background of the disease in his case.
Collapse
Affiliation(s)
- Nikoletta Nagy
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
- HUN-REN-SZTE Functional Clinical Genetic Research Group, 6720 Szeged, Hungary
| | - Margit Pal
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
- HUN-REN-SZTE Functional Clinical Genetic Research Group, 6720 Szeged, Hungary
| | - Jozsef Kun
- Hungarian Centre for Genomics and Bioinformatics, Szentagothai Research Centre, University of Pecs, 7624 Pecs, Hungary; (J.K.); (B.G.); (P.U.); (A.G.)
| | - Bence Galik
- Hungarian Centre for Genomics and Bioinformatics, Szentagothai Research Centre, University of Pecs, 7624 Pecs, Hungary; (J.K.); (B.G.); (P.U.); (A.G.)
| | - Peter Urban
- Hungarian Centre for Genomics and Bioinformatics, Szentagothai Research Centre, University of Pecs, 7624 Pecs, Hungary; (J.K.); (B.G.); (P.U.); (A.G.)
| | - Marta Medvecz
- Department of Dermatology, Venereology and Dermatooncology, Semmelweis University, 1095 Budapest, Hungary;
- ERN-Skin Reference Centre, Semmelweis University, 1095 Budapest, Hungary
| | - Beata Fabos
- Mor Kaposi Teaching Hospital of Somogy County, 7400 Kaposvar, Hungary;
| | - Alexandra Neller
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
| | - Aliasgari Abdolreza
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
| | - Judit Danis
- HUN-REN-SZTE Dermatological Research Group, 6720 Szeged, Hungary;
- Department of Immunology, University of Szeged, 6720 Szeged, Hungary
| | - Viktoria Szabo
- Department of Ophthalmology, Semmelweis University, 1085 Budapest, Hungary
| | - Zhuo Yang
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany (M.B.)
| | - Stefanie Fenske
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany (M.B.)
| | - Martin Biel
- Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany (M.B.)
| | - Attila Gyenesei
- Hungarian Centre for Genomics and Bioinformatics, Szentagothai Research Centre, University of Pecs, 7624 Pecs, Hungary; (J.K.); (B.G.); (P.U.); (A.G.)
| | - Eva Adam
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
- HUN-REN-SZTE Functional Clinical Genetic Research Group, 6720 Szeged, Hungary
| | - Marta Szell
- Department of Medical Genetics, University of Szeged, 6720 Szeged, Hungary; (M.P.); (A.N.); (A.A.); (E.A.); (M.S.)
- HUN-REN-SZTE Functional Clinical Genetic Research Group, 6720 Szeged, Hungary
| |
Collapse
|
|
2
|
Wang J, Fan T, Du Z, Xu L, Chen Y, Zhang L, Gao H, Li J, Ma Y, Gao X. Genome-Wide Association Analysis Identifies the PMEL Gene Affecting Coat Color and Birth Weight in Simmental × Holstein. Animals (Basel) 2023; 13:3821. [PMID: 38136858 PMCID: PMC10740715 DOI: 10.3390/ani13243821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/01/2023] [Accepted: 12/06/2023] [Indexed: 12/24/2023] Open
Abstract
Coat color and birth weight, as easily selected traits in cattle, play important roles in cattle breeding. Therefore, we carried out a genome-wide association study on birth weight and coat color to identify loci or potential linkage regions in 233 Simmental × Holstein crossbred beef cattle. The results revealed that nine SNPs were significantly associated with coat color (rs137169378, rs110022687, rs136002689, Hypotrichosis_PMel17, PMEL_1, rs134930689, rs383170073, rs109924971, and rs109146332), and these were in RNF41, ZC3H10, ERBB3, PMEL, and OR10A7 on BTA5. Interestingly, rs137169378, rs110022687, rs136002689, Hypotrichosis_PMel17, and PMEL_1 showed strong linkage disequilibrium (r2 > 0.8) and were significantly associated with coat color. Notably, Hypotrichosis_PMel17 and PMEL_1 were located in the gene PMEL (p = 2.22 × 10-18). Among the five significant SNPs associated with coat color, the birth weight of heterozygous individuals (AB) was greater than that of homozygous individuals (AA). Notably, the birth weight of heterozygous individuals with Hypotrichosis_PMel17 and PMEL_1 genotypes was significantly greater than that of homozygous individuals (0.01 < p < 0.05). Interestingly, the two loci were homozygous in black/white individuals and heterozygous in gray/white individuals, and the birth weight of heterozygous brown/white individuals (43.82 ± 5.25 kg) was greater than that of homozygous individuals (42.58 ± 3.09 kg). The birth weight of calves with the parental color (41.95 ± 3.53 kg) was significantly lower than that of calves with a non-parental color (43.54 ± 4.78 kg) (p < 0.05), and the birth weight of gray/white individuals (49.40 ± 7.11 kg) was the highest. Overall, PMEL appears to be a candidate gene affecting coat color in cattle, and coat color may have a selective effect on birth weight. This study provides a foundation for the breeding of beef cattle through GWAS for coat color and birth weight.
Collapse
Affiliation(s)
- Jing Wang
- Laboratory of Molecular Biology and Bovine Breeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (J.W.); (T.F.); (Z.D.); (L.X.); (Y.C.); (L.Z.); (H.G.); (J.L.)
| | - Tingting Fan
- Laboratory of Molecular Biology and Bovine Breeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (J.W.); (T.F.); (Z.D.); (L.X.); (Y.C.); (L.Z.); (H.G.); (J.L.)
| | - Zhenwei Du
- Laboratory of Molecular Biology and Bovine Breeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (J.W.); (T.F.); (Z.D.); (L.X.); (Y.C.); (L.Z.); (H.G.); (J.L.)
| | - Lingyang Xu
- Laboratory of Molecular Biology and Bovine Breeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (J.W.); (T.F.); (Z.D.); (L.X.); (Y.C.); (L.Z.); (H.G.); (J.L.)
| | - Yan Chen
- Laboratory of Molecular Biology and Bovine Breeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (J.W.); (T.F.); (Z.D.); (L.X.); (Y.C.); (L.Z.); (H.G.); (J.L.)
| | - Lupei Zhang
- Laboratory of Molecular Biology and Bovine Breeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (J.W.); (T.F.); (Z.D.); (L.X.); (Y.C.); (L.Z.); (H.G.); (J.L.)
| | - Huijiang Gao
- Laboratory of Molecular Biology and Bovine Breeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (J.W.); (T.F.); (Z.D.); (L.X.); (Y.C.); (L.Z.); (H.G.); (J.L.)
| | - Junya Li
- Laboratory of Molecular Biology and Bovine Breeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (J.W.); (T.F.); (Z.D.); (L.X.); (Y.C.); (L.Z.); (H.G.); (J.L.)
| | - Yi Ma
- Animal Husbandry Institute, Tianjin Academy of Agricultural Sciences, Tianjin 300384, China
| | - Xue Gao
- Laboratory of Molecular Biology and Bovine Breeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; (J.W.); (T.F.); (Z.D.); (L.X.); (Y.C.); (L.Z.); (H.G.); (J.L.)
| |
Collapse
|
|
3
|
Kawahara R, Usami T, Arakawa S, Kamo H, Suzuki T, Komatsu R, Hara H, Niwa Y, Shimizu E, Dohmae N, Shimizu S, Simizu S. Biogenesis of fibrils requires C-mannosylation of PMEL. FEBS J 2023; 290:5373-5394. [PMID: 37552474 DOI: 10.1111/febs.16927] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Revised: 07/22/2023] [Accepted: 08/07/2023] [Indexed: 08/09/2023]
Abstract
Premelanosome protein (PMEL), a melanocyte-specific glycoprotein, has an essential role in melanosome maturation, assembling amyloid fibrils for melanin deposition. PMEL undergoes several post-translational modifications, including N- and O-glycosylations, which are associated with proper melanosome development. C-mannosylation is a rare type of protein glycosylation at a tryptophan residue that might regulate the secretion and localization of proteins. PMEL has one putative C-mannosylation site in its core amyloid fragment (CAF); however, there is no report focusing on C-mannosylation of PMEL. To investigate this, we expressed recombinant PMEL in SK-MEL-28 human melanoma cells and purified the protein. Mass spectrometry analyses demonstrated that human PMEL is C-mannosylated at multiple tryptophan residues in its CAF and N-terminal fragment (NTF). In addition to the W153 or W156 residue (CAF), which lies in the consensus sequence for C-mannosylation, the W104 residue (NTF) was C-mannosylated without the consensus sequence. To determine the effects of the modifications, we deleted the PMEL gene by using CRISPR/Cas9 technology and re-expressed wild-type or C-mannosylation-defective mutants of PMEL, in which the C-mannosylated tryptophan was replaced with a phenylalanine residue (WF mutation), in SK-MEL-28 cells. Importantly, fibril-containing melanosomes were significantly decreased in W104F mutant PMEL-re-expressing cells compared with wild-type PMEL, observed using transmission electron microscopy. Furthermore, western blot and immunofluorescence analysis suggested that the W104F mutation may cause mild endoplasmic reticulumretention, possibly associated with early misfolding, and lysosomal misaggregation, thus reducing functional fibril formation. Our results demonstrate that C-mannosylation of PMEL is required for proper melanosome development by regulating PMEL-derived fibril formation.
Collapse
Affiliation(s)
- Ryota Kawahara
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Tomoko Usami
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Satoko Arakawa
- Department of Pathological Cell Biology, Medical Research Institute, Tokyo Medical and Dental University, Japan
- Research Core, Institute of Research, Tokyo Medical and Dental University, Japan
| | - Hiroki Kamo
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Takehiro Suzuki
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Wako, Japan
| | - Ryosuke Komatsu
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Hiroyuki Hara
- Division of Anatomical Science, Department of Functional Morphology, Nihon University School of Medicine, Tokyo, Japan
| | - Yuki Niwa
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Erina Shimizu
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan
| | - Naoshi Dohmae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Wako, Japan
| | - Shigeomi Shimizu
- Department of Pathological Cell Biology, Medical Research Institute, Tokyo Medical and Dental University, Japan
| | - Siro Simizu
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, Yokohama, Japan
| |
Collapse
|
|
4
|
Oculo-Cutaneous Albinism Type 4 (OCA4): Phenotype-Genotype Correlation. Genes (Basel) 2022; 13:genes13122198. [PMID: 36553465 PMCID: PMC9777904 DOI: 10.3390/genes13122198] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/04/2022] [Accepted: 11/15/2022] [Indexed: 11/25/2022] Open
Abstract
Albinism is a genetic disorder, present worldwide, caused by mutations in genes affecting melanin production or transport in the skin, hair and eyes. To date, mutations in at least 20 different genes have been identified. Oculo-cutaneous Albinism type IV (OCA4) is the most frequent form in Asia but has been reported in all populations, including Europeans. Little is known about the genotype-phenotype correlation. We identified two main phenotypes via the analysis of 30 OCA4 patients with a molecularly proven diagnosis. The first, found in 20 patients, is clinically indistinguishable from the classical OCA1 phenotype. The genotype-to-phenotype correlation suggests that this phenotype is associated with homozygous or compound heterozygous nonsense or deletion variants with frameshift leading to translation interruption in the SLC45A2 gene. The second phenotype, found in 10 patients, is characterized by very mild hypopigmentation of the hair (light brown or even dark hair) and skin that is similar to the general population. In this group, visual acuity is variable, but it can be subnormal, foveal hypoplasia can be low grade or even normal, and nystagmus may be lacking. These mild to moderate phenotypes are associated with at least one missense mutation in SLC45A2.
Collapse
|