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Aryee SND, Owusu-Adjei D, Osei-Amponsah R, Skinner BM, Amuzu-Aweh EN, Ahunu B, Enright A, Sargent CA. Population Structure and Genomic Characterisation of the Ashanti Dwarf Pig of Ghana. Animals (Basel) 2024; 14:792. [PMID: 38473177 DOI: 10.3390/ani14050792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Revised: 02/28/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024] Open
Abstract
There is still limited information on the genomic structure and genetic diversity of African pigs. Genetic diversity studies can contribute significantly to the genetic improvement and conservation of African pigs. This study presents a genetic diversity analysis and population structure of pig breeds in Ghana, with a focus on the Ashanti Dwarf pig (ADP), an indigenous pig breed of Ghana. A total of 167 pigs sampled in Ghana and populations consisting of Ashanti Dwarf pigs (n = 106), exotics (mostly European pigs) (n = 11), crosses (between indigenous and exotic breeds) (n = 44), and unknown breeds (nondescript) (n = 6) were genotyped using Porcine SNP60K BeadChip. Moderate heterozygosity levels, ranging from 0.28 for Ashanti Dwarf pigs to 0.31 for exotic pigs (mostly European pigs), were observed. Principal component analysis of the pig populations within Ghana resulted in two distinct clusters of pigs: (i) Northern and (ii) Southern regional clusters. The PCA based on breed also resulted in four clusters: (i) ADPs; (ii) exotics (iii) crossbreeds between ADP and exotics; (iv) unknown breed types. The PCA demonstrated that the clustering was influenced by genetics, geographical location, production systems, and practices. ADMIXTURE-based analysis also showed that the populations within Ghana are admixed. FST analysis revealed SNPs associated with QTLs for traits such as disease resilience and growth among ADP populations within the different regional and ecological zones of Ghana.
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Affiliation(s)
- Sethlina Naa Dodua Aryee
- Department of Pathology, University of Cambridge, Cambridge CB2 1TN, UK
- Bristol Medical School, University of Bristol, Bristol BS8 1QU, UK
| | - Dennis Owusu-Adjei
- Department of Animal Science, University of Ghana, Accra P.O. Box LG43, Ghana
| | | | | | | | - Benjamin Ahunu
- Department of Animal Science, University of Ghana, Accra P.O. Box LG43, Ghana
| | - Anton Enright
- Department of Pathology, University of Cambridge, Cambridge CB2 1TN, UK
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2
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Woods T, Sergeev YV. Evaluating the Cysteine-Rich and Catalytic Subdomains of Human Tyrosinase and OCA1-Related Mutants Using 1 μs Molecular Dynamics Simulation. Int J Mol Sci 2023; 24:13032. [PMID: 37685839 PMCID: PMC10487697 DOI: 10.3390/ijms241713032] [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: 05/31/2023] [Revised: 08/15/2023] [Accepted: 08/19/2023] [Indexed: 09/10/2023] Open
Abstract
The inherited disorder oculocutaneous albinism type 1 (OCA1) is caused by mutations in the TYR gene encoding tyrosinase (Tyr), an enzyme essential to producing pigments throughout the human body. The intramelanosomal domain of Tyr consists of the cysteine-rich and tyrosinase catalytic subdomains, which are essential for enzymatic activity. In protein unfolding, the roles of these subdomains are not well established. Here, we performed six molecular dynamics simulations at room temperature for Tyr and OCA1-related mutant variants P406L and R402Q intramelanosomal domains. The proteins were simulated for 1 μs in water and urea to induce unfolding. In urea, we observed increases in surface area, decreases in intramolecular hydrogen bonding, and decreases in hydrophobic interactions, suggesting a 'molten globule' state for each protein. Between all conditions, the cysteine-rich subdomain remains stable, whereas the catalytic subdomain shows increased flexibility. This flexibility is intensified by the P406L mutation, while R402Q increases the catalytic domain's rigidity. The cysteine-rich subdomain is rigid, preventing the protein from unfolding, whereas the flexibility of the catalytic subdomain accommodates mutational changes that could inhibit activity. These findings match the conclusions from our experimental work suggesting the function alteration by the P406L mutation, and the potential role of R402Q as a polymorphism.
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Affiliation(s)
| | - Yuri V. Sergeev
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA;
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Prospective Study of the Phenotypic and Mutational Spectrum of Ocular Albinism and Oculocutaneous Albinism. Genes (Basel) 2021; 12:genes12040508. [PMID: 33808351 PMCID: PMC8065601 DOI: 10.3390/genes12040508] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 03/15/2021] [Accepted: 03/26/2021] [Indexed: 02/07/2023] Open
Abstract
Albinism encompasses a group of hereditary disorders characterized by reduced or absent ocular pigment and variable skin and/or hair involvement, with syndromic forms such as Hermansky-Pudlak syndrome and Chédiak-Higashi syndrome. Autosomal recessive oculocutaneous albinism (OCA) is phenotypically and genetically heterogenous (associated with seven genes). X-linked ocular albinism (OA) is associated with only one gene, GPR143. We report the clinical and genetic outcomes of 44 patients, from 40 unrelated families of diverse ethnicities, with query albinism presenting to the ocular genetics service at Moorfields Eye Hospital NHS Foundation Trust between November 2017 and October 2019. Thirty-six were children (≤ 16 years) with a median age of 31 months (range 2-186), and eight adults with a median age of 33 years (range 17-39); 52.3% (n = 23) were male. Genetic testing using whole genome sequencing (WGS, n = 9) or a targeted gene panel (n = 31) gave an overall diagnostic rate of 42.5% (44.4% (4/9) with WGS and 41.9% (13/31) with panel testing). Seventeen families had confirmed mutations in TYR (n = 9), OCA2, (n = 4), HPS1 (n = 1), HPS3 (n = 1), HPS6 (n = 1), and GPR143 (n = 1). Molecular diagnosis of albinism remains challenging due to factors such as missing heritability. Differential diagnoses must include SLC38A8-associated foveal hypoplasia and syndromic forms of albinism.
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May L, Merrill K, Connett JE, Summers CG. Does Early Glasses Wear Improve Visual Outcome in OCA1A? J Binocul Vis Ocul Motil 2021; 71:1-6. [PMID: 33470906 DOI: 10.1080/2576117x.2020.1856609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Purpose: Oculocutaneous albinism type 1A (OCA1A), with lifelong absent melanin in skin, hair, and eyes, is the most severe type of albinism with greatest ametropia and poorest vision. We evaluated the relationship between age when spectacles were begun and visual outcome, in addition to status of refraction, in OCA1A. Methods: After IRB approval, a retrospective review of 70 consecutive charts of patients with OCA1A identified 24 fitting inclusion criterion of BCVA recorded at age 10-12 years. Exclusion criteria were those with other vision-threatening diagnoses and patients seen for a single visit. We recorded sex, age at beginning glasses, and refraction and BCVA at age 10-12 and most recent visit. Data were arbitrarily grouped by those initiating glasses at ≤ age 12 months and > age 12 months. Results: Regression analysis showed a larger degree of astigmatism was weakly associated with worse vision at age 10-12 years. A weakly positive relationship was found between poorer BCVA at last visit and older age at which glasses were initiated. All receiving glasses by age 1 and only half receiving glasses when older had improved visual acuity from age 10-12 years to last follow up. Conclusion: Additional study of a larger sample of this rare disorder is needed to determine if early glasses wear improves later BCVA.
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Affiliation(s)
- Laura May
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota , Minneapolis, Minnesota
| | - Kimberly Merrill
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota , Minneapolis, Minnesota
| | - John E Connett
- School of Public Health, Division of Biostatistics, University of Minnesota , Minneapolis, Minnesota
| | - C Gail Summers
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota , Minneapolis, Minnesota.,Department of Pediatrics, University of Minnesota , Minneapolis, Minnesota
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Sayed KM, Mahmoud Abdellah M, Gad Kamel A. Analysis of the Refractive Profile of Children with Oculocutaneous Albinism versus an Age-Matched Non-Albino Group. Clin Ophthalmol 2021; 15:73-78. [PMID: 33447012 PMCID: PMC7802909 DOI: 10.2147/opth.s286126] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Accepted: 12/08/2020] [Indexed: 11/26/2022] Open
Abstract
Purpose To find out and analyze the points of difference in the refractive profile between children with complete oculocutaneous albinism (OCA) and an age-matched, non-albino group seeking paediatric ophthalmic examination. Methods A cross-sectional study was conducted on 164 infants and young children in Paediatric Ophthalmology Center, Sohag City, Egypt. Informed consent was obtained from the participants’ guardians. The study divided the population into 2 equal groups: albino group = 82 eyes, non-albino group = 82 eyes. Cycloplegic refraction and average keratometric measurements using the hand-held autokeratometer were taken for the study groups. Results In the albino group, astigmatism and hypermetropia were the most common refractive errors, 100% and 62% respectively, with significant difference between both groups. Mean total (TA), corneal (CA) and lenticular astigmatism (LA) were significantly higher in albino group (P<0.05). All albino eyes were high astigmats (≥1.25 D). Conclusion This study is novel in being comparative and includes the largest sample size ever reported for albino eyes of infants and children. High WTR astigmatism is the most prevalent refractive error in albinos with an overall bias toward hyperopia, but extreme errors (>−11.00D myopia or >+10.00D hyperopia) are not common. Albino eyes have a significantly higher degree of LA which compensates for the high CA to decrease the amount of TA. The study emphasizes the importance of refraction examination and visual rehabilitation for OCA children as early as possible to reduce eye morbidity-associated low vision.
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Affiliation(s)
- Khulood Muhammad Sayed
- The Department of Ophthalmology, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Marwa Mahmoud Abdellah
- The Department of Ophthalmology, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt
| | - Ahmad Gad Kamel
- The Department of Ophthalmology, Sohag Faculty of Medicine, Sohag University, Sohag, Egypt
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Varghese PK, Abu-Asab M, Dimitriadis EK, Dolinska MB, Morcos GP, Sergeev YV. Tyrosinase Nanoparticles: Understanding the Melanogenesis Pathway by Isolating the Products of Tyrosinase Enzymatic Reaction. Int J Mol Sci 2021; 22:ijms22020734. [PMID: 33450959 PMCID: PMC7828394 DOI: 10.3390/ijms22020734] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/09/2021] [Accepted: 01/11/2021] [Indexed: 12/22/2022] Open
Abstract
Human Tyrosinase (Tyr) is the rate-limiting enzyme of the melanogenesis pathway. Tyr catalyzes the oxidation of the substrate L-DOPA into dopachrome and melanin. Currently, the characterization of dopachrome-related products is difficult due to the absence of a simple way to partition dopachrome from protein fraction. Here, we immobilize catalytically pure recombinant human Tyr domain (residues 19–469) containing 6xHis tag to Ni-loaded magnetic beads (MB). Transmission electron microscopy revealed Tyr-MB were within limits of 168.2 ± 24.4 nm while the dark-brown melanin images showed single and polymerized melanin with a diameter of 121.4 ± 18.1 nm. Using Hill kinetics, we show that Tyr-MB has a catalytic activity similar to that of intact Tyr. The diphenol oxidase reactions of L-DOPA show an increase of dopachrome formation with the number of MB and with temperature. At 50 °C, Tyr-MB shows some residual catalytic activity suggesting that the immobilized Tyr has increased protein stability. In contrast, under 37 °C, the dopachrome product, which is isolated from Tyr-MB particles, shows that dopachrome has an orange-brown color that is different from the color of the mixture of L-DOPA, Tyr, and dopachrome. In the future, Tyr-MB could be used for large-scale productions of dopachrome and melanin-related products and finding a treatment for oculocutaneous albinism-inherited diseases.
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Affiliation(s)
- Paul K. Varghese
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (P.K.V.); (M.A.-A.); (M.B.D.); (G.P.M.)
| | - Mones Abu-Asab
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (P.K.V.); (M.A.-A.); (M.B.D.); (G.P.M.)
| | - Emilios K. Dimitriadis
- NIH Shared Resources on Biomedical Engineering and Physical Science, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Monika B. Dolinska
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (P.K.V.); (M.A.-A.); (M.B.D.); (G.P.M.)
| | - George P. Morcos
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (P.K.V.); (M.A.-A.); (M.B.D.); (G.P.M.)
| | - Yuri V. Sergeev
- National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA; (P.K.V.); (M.A.-A.); (M.B.D.); (G.P.M.)
- Correspondence:
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Kumar A, Panda D, Mohanty S, Biswal M, Dey P, Dash M, Sah RP, Kumar S, Baig MJ, Behera L. Role of sedoheptulose-1,7 bisphosphatase in low light tolerance of rice ( Oryza sativa L.). PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2020; 26:2465-2485. [PMID: 33424159 PMCID: PMC7772133 DOI: 10.1007/s12298-020-00905-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 09/30/2020] [Accepted: 10/23/2020] [Indexed: 05/11/2023]
Abstract
Rice grain yield is drastically reduced under low light especially in kharif (wet) season due to cloudy weather during most part of crop growth. Therefore, 50-60% of yield penalty was observed. To overcome this problem, identification of low light tolerant rice genotypes with a high buffering capacity trait such as photosynthetic rate has to be developed. Sedoheptulose-1,7 bisphosphatase, a light-regulated enzyme, plays pivotal role in the Calvin cycle by regenerating the substrate (RuBP) for RuBisCo and therefore, indirectly regulates the influx of CO2 for this crucial process. We found a potential role of SBPase expression and activity in low light tolerant and susceptible rice genotypes by analyzing its influence on net photosynthetic rate and biomass. We observed a significant relationship of yield with photosynthesis, SBPase expression and activity especially under low light conditions. Two tolerant and two susceptible rice genotypes were used for the present study. Tolerant genotypes exhibited significant but least reduction compared to susceptible genotypes in the expression and activity of SBPase, which was also manifested in its photosynthetic rate and finally in the grain yield under low light. However, susceptible genotypes showed significant reduction in SBPase activity along with photosynthesis and grain yield suggesting that tracking the expression and activity of SBPase could form a simple and reliable method to identify the low light tolerant rice cultivars. The data were analyzed using the Indostat 7.5, Tukey-Kramer method through Microsoft Excel 2019 and PAST4.0 software. The significant association of SBPase activity with the grain yield, net assimilation rate, electron transfer rate, biomass and grain weight were observed under low light stress. These traits should be considered while selecting and breeding for low light tolerant cultivars. Thus, SBPase plays a major role in the low light tolerance mechanism in rice.
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Affiliation(s)
- Awadhesh Kumar
- ICAR-National Rice Research Institute, Cuttack, Odisha 753006 India
| | - Darshan Panda
- ICAR-National Rice Research Institute, Cuttack, Odisha 753006 India
| | - Soumya Mohanty
- ICAR-National Rice Research Institute, Cuttack, Odisha 753006 India
| | - Monalisha Biswal
- ICAR-National Rice Research Institute, Cuttack, Odisha 753006 India
| | - Prajjal Dey
- Faculty of Agriculture, Sri Sri University, Cuttack, Odisha 754006 India
| | - Manaswini Dash
- ICAR-National Rice Research Institute, Cuttack, Odisha 753006 India
| | | | - Sudhir Kumar
- ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | | | - Lambodar Behera
- ICAR-National Rice Research Institute, Cuttack, Odisha 753006 India
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8
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Current and emerging treatments for albinism. Surv Ophthalmol 2020; 66:362-377. [PMID: 33129801 DOI: 10.1016/j.survophthal.2020.10.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 10/07/2020] [Accepted: 10/21/2020] [Indexed: 12/24/2022]
Abstract
Albinism is a group of rare inherited disorders arising from impairment of melanin biosynthesis. The reduction of melanin synthesis leads to hypopigmentation of the skin and eyes. A wide range of ophthalmic manifestations arise from albinism, including reduction of visual acuity, nystagmus, strabismus, iris translucency, foveal hypoplasia, fundus hypopigmentation, and abnormal decussation of retinal ganglion cell axons at the optic chiasm. Currently, albinism is incurable, and treatment aims either surgically or pharmacologically to optimize vision and protect the skin; however, novel therapies that aim to directly address the molecular errors of albinism, such as l-dihydroxyphenylalanine and nitisinone, are being developed and have entered human trials though with limited success. Experimental gene-based strategies for editing the genetic errors in albinism have also met early success in animal models. The emergence of these new therapeutic modalities represents a new era in the management of albinism. We focus on the known genetic subtypes, clinical assessment, and existing and emerging therapeutic options for the nonsyndromic forms of albinism.
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Young KL, Kassouf C, Dolinska MB, Anderson DE, Sergeev YV. Human Tyrosinase: Temperature-Dependent Kinetics of Oxidase Activity. Int J Mol Sci 2020; 21:ijms21030895. [PMID: 32019134 PMCID: PMC7037427 DOI: 10.3390/ijms21030895] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 01/27/2020] [Accepted: 01/28/2020] [Indexed: 12/24/2022] Open
Abstract
Human tyrosinase (Tyr) is involved in pigment biosynthesis, where mutations in its corresponding gene TYR have been linked to oculocutaneous albinism 1, an autosomal recessive disorder. Although the enzymatic capabilities of Tyr have been well-characterized, the thermodynamic driving forces underlying melanogenesis remain unknown. Here, we analyze protein binding using the diphenol oxidase behavior of Tyr and van ’t Hoff temperature-dependent analysis. Recombinant Tyr was expressed and purified using a combination of affinity and size-exclusion chromatography. Michaelis-Menten constants were measured spectrophotometrically from diphenol oxidase reactions of Tyr, using L-3,4-dihydroxyphenylalanine (L-DOPA) as a substrate, at temperatures: 25, 31, 37, and 43 °C. Under the same conditions, the Tyr structure and the L-DOPA binding activity were simulated using 3 ns molecular dynamics and docking. The thermal Michaelis-Menten kinetics data were subjected to the van ‘t Hoff analysis and fitted with the computational model. The temperature-dependent analysis suggests that the association of L-DOPA with Tyr is a spontaneous enthalpy-driven reaction, which becomes unfavorable at the final step of dopachrome formation.
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Affiliation(s)
- Kenneth L. Young
- National Eye Institute, National Institutes of Health, 31 Center Drive MSC 2510, Bethesda, MD 20892, USA
| | - Claudia Kassouf
- National Eye Institute, National Institutes of Health, 31 Center Drive MSC 2510, Bethesda, MD 20892, USA
| | - Monika B. Dolinska
- National Eye Institute, National Institutes of Health, 31 Center Drive MSC 2510, Bethesda, MD 20892, USA
| | - David Eric Anderson
- National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 6 Center Dr. MSC2775, Bethesda, MD 20892, USA
| | - Yuri V. Sergeev
- National Eye Institute, National Institutes of Health, 31 Center Drive MSC 2510, Bethesda, MD 20892, USA
- Correspondence: ; Tel.: +1-301-594-7053; Fax: +1-301-402-1214
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Shakil M, Harlalka GV, Ali S, Lin S, D'Atri I, Hussain S, Nasir A, Shahzad MA, Ullah MI, Self JE, Baple EL, Crosby AH, Mahmood S. Tyrosinase (TYR) gene sequencing and literature review reveals recurrent mutations and multiple population founder gene mutations as causative of oculocutaneous albinism (OCA) in Pakistani families. Eye (Lond) 2019; 33:1339-1346. [PMID: 30996339 PMCID: PMC7005860 DOI: 10.1038/s41433-019-0436-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 01/21/2019] [Accepted: 03/25/2019] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To investigate eight previously unreported Pakistani families with genetically undefined OCA for mutations in TYR. METHODS Sanger sequencing of TYR has been performed in eight families with OCA phenotype. Mutation analysis was performed to establish the pathogenic role of novel mutation. Bioinformatics analysis was performed to predict the structural and functional impacts on protein due to the mutation. RESULTS In this study, we identified six likely pathogenic variants of TYR (c.272 G>A, c.308 G>A, c.346C>T, c.715 C>T, c.832 C>T and c.1255 G>A), including one novel variant (c.308 G>A; p.Cys103Tyr), segregating as appropriate in each family. Cys103 lies in the highly conserved region of the tyrosinase enzyme, and p.Cys103Tyr is predicted to disturb enzymatic function via alteration of the configurational orientation of TYR leading to a more rigid polypeptide structure. We have also reviewed the mutation spectrum of TYR in Pakistani ethnicity. Published data on OCA families proposed that ~40% have been associated with genetic variations in the TYR gene. The mutations reported in this study have now been described with varying frequencies in Pakistani families, including very rare/unique mutations. CONCLUSION A literature review of TYR gene mutations in Pakistani populations, combined with our genetic data, identified a number of gene mutations likely to represent regional ancestral founder mutations of relevance to Pakistani populations, in addition to sporadic and recurrent 'hotspot' mutations present repeatedly in other regions worldwide.
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Affiliation(s)
- Muhammad Shakil
- Department of Biochemistry, University of Health Sciences (UHS), Lahore, Pakistan
- RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Barrack Road, Exeter, Devon, EX2 5DW, UK
- Department of Biochemistry, Services Institute of Medical Sciences, Services Hospital, Lahore, Pakistan
| | - Gaurav V Harlalka
- RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Barrack Road, Exeter, Devon, EX2 5DW, UK
| | - Shamshad Ali
- Department of Ophthalmology, Services Institute of Medical Sciences, Services Hospital, Lahore, Pakistan
| | - Siying Lin
- RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Barrack Road, Exeter, Devon, EX2 5DW, UK
| | - Ilaria D'Atri
- RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Barrack Road, Exeter, Devon, EX2 5DW, UK
| | - Shabbir Hussain
- Department of Biochemistry, University of Health Sciences (UHS), Lahore, Pakistan
| | - Abdul Nasir
- Synthetic Protein Engineering Lab (SPEL), Department of Molecular Science and Technology, Ajou University, Suwon, 443-749, South Korea
| | - Muhammad Aiman Shahzad
- Department of Human Genetics and Molecular Biology, University of Health Sciences (UHS), Lahore, Pakistan
| | - Muhammad Ikram Ullah
- Department of Biochemistry, University of Health Sciences (UHS), Lahore, Pakistan
- Department of Clinical Laboratory Sciences, Jouf University, Sakaka-2014, Saudi Arabia
| | - Jay E Self
- Clinical and Experimental Sciences, University of Southampton, Southampton, UK
| | - Emma L Baple
- RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Barrack Road, Exeter, Devon, EX2 5DW, UK
| | - Andrew H Crosby
- RD&E (Wonford) NHS Foundation Trust, University of Exeter Medical School, Barrack Road, Exeter, Devon, EX2 5DW, UK
| | - Saqib Mahmood
- Department of Human Genetics and Molecular Biology, University of Health Sciences (UHS), Lahore, Pakistan.
- Institute of Biomedical and Allied Health Sciences, University of Health Sciences (UHS), Lahore, Pakistan.
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Luo D, Linpeng S, Zeng L, Tan H, Li Z, Wu L. Molecular genetic study of 59 Chinese Oculocutaneous albinism families. Eur J Med Genet 2019; 62:103709. [PMID: 31229681 DOI: 10.1016/j.ejmg.2019.103709] [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: 01/05/2019] [Revised: 04/24/2019] [Accepted: 06/19/2019] [Indexed: 12/11/2022]
Abstract
Oculocutaneous albinism is an autosomal recessive disorder characterized by either a complete lack of or reduction in melanin biosynthesis in the skin, hair, and eyes. The aim of the present study was to identify the molecular basis for 59 Chinese OCA families. In this study, compound heterozygous or homozygous pathogenic variants were found in 53 families, 4 families possessed only one heterozygous variant, and the pathogenic variants of 2 families remain undiscovered by using Sanger sequencing, whole exome sequencing and multiplex ligation-dependent probe amplification. We have identified a total of 55 variants including 21 novel variants in TYR, OCA2, SLC45A2, SLC24A5, and HPS1. The 21 novel variants include 11 missense changes, 4 nonsense changes, 2 splice site changes, 1 frameshift and 3 gross deletions. Forty-six variants including 14 novel variants were segregated with the phenotype in 37 families. We conducted RT-PCR of the novel splicing site variant (c.399-14G > A) of HPS1 and verified that the variant would result in the inclusion of 12 bp of intronic material in exon 6 of HPS1. The results of platelet whole mount electron microscopy further confirmed the diagnosis of HPS1. These novel variants identified in our study expand the mutational spectrum of the disease, which contributes to prenatal diagnosis and genetic counselling.
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Affiliation(s)
- Dan Luo
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Siyuan Linpeng
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Lanlan Zeng
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Hu Tan
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Zhuo Li
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Lingqian Wu
- Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China.
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McKay BS. Pigmentation and vision: Is GPR143 in control? J Neurosci Res 2019; 97:77-87. [PMID: 29761529 PMCID: PMC6235735 DOI: 10.1002/jnr.24246] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/21/2018] [Accepted: 03/21/2018] [Indexed: 12/30/2022]
Abstract
Albinism, typically characterized by decreased melanin synthesis, is associated with significant visual deficits owing to developmental changes during neurosensory retina development. All albinism is caused by genetic mutations in a group of diverse genes including enzymes, transporters, G-protein coupled receptor. Interestingly, these genes are not expressed in the neurosensory retina. Further, regardless of cause of albinism, all forms of albinism have the same retinal pathology, the extent of which is variable. In this review, we explore the possibility that this similarity in retinal phenotype is because all forms of albinism funnel through the same final common pathway. There are currently seven known genes linked to the seven forms of ocular cutaneous albinism. These types of albinism are the most common, and result in changes to all pigmented tissues (hair, skin, eyes). We will discuss the incidence and mechanism, where known, to develop a picture as to how the mutations cause albinism. Next, we will examine the one form of albinism which causes tissue-specific pathology, ocular albinism, where the eye exhibits the retinal albinism phenotype despite near normal melanin synthesis. We will discuss a potential way to treat the disease and restore normal retinal development. Finally, we will briefly discuss the possibility that this same pathway may intersect with the most common cause of permanent vision loss in the elderly.
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Affiliation(s)
- Brian S McKay
- Department of Ophthalmology and Vision Science, University of Arizona, Tucson, Arizona
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Krause A, Seymour H, Ramsay M. Common and Founder Mutations for Monogenic Traits in Sub-Saharan African Populations. Annu Rev Genomics Hum Genet 2018; 19:149-175. [DOI: 10.1146/annurev-genom-083117-021256] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This review highlights molecular genetic studies of monogenic traits where common pathogenic mutations occur in black families from sub-Saharan Africa. Examples of founder mutations have been identified for oculocutaneous albinism, cystic fibrosis, Fanconi anemia, and Gaucher disease. Although there are few studies from Africa, some of the mutations traverse populations across the continent, and they are almost all different from the common mutations observed in non-African populations. Myotonic dystrophy is curiously absent among Africans, and nonsyndromic deafness does not arise from mutations in GJB2 and GJB7. Locus heterogeneity is present for Huntington disease, with two common triplet expansion loci in Africa, HTT and JPH3. These findings have important clinical consequences for diagnosis, treatment, and genetic counseling in affected families. We currently have just a glimpse of the molecular etiology of monogenic diseases in sub-Saharan Africa, a proverbial “ears of the hippo” situation.
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Affiliation(s)
- Amanda Krause
- Division of Human Genetics, National Health Laboratory Service, and Division of Human Genetics, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Heather Seymour
- Division of Human Genetics, National Health Laboratory Service, and Division of Human Genetics, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Michèle Ramsay
- Division of Human Genetics, National Health Laboratory Service, and Division of Human Genetics, School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
- Sydney Brenner Institute for Molecular Bioscience, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
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Membrane-associated human tyrosinase is an enzymatically active monomeric glycoprotein. PLoS One 2018; 13:e0198247. [PMID: 29870551 PMCID: PMC5988326 DOI: 10.1371/journal.pone.0198247] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 05/16/2018] [Indexed: 11/19/2022] Open
Abstract
Human tyrosinase (hTyr) is a Type 1 membrane bound glycoenzyme that catalyzes the initial and rate-limiting steps of melanin production in the melanosome. Mutations in the Tyr gene are linked to oculocutaneous albinism type 1 (OCA1), an autosomal recessive disorder. Currently, the application of enzyme replacement therapy for a treatment of OCA1 is hampered by the absence of pure hTyr. Here, full-length hTyr (residues 1-529) was overexpressed in Trichoplusia ni larvae infected with a baculovirus, solubilized with detergent and purified using chromatography. Michaelis-Menten kinetics, enzymatic specific activity, and analytical ultracentrifugation were used to compare the hTyr in detergent with the soluble recombinant intra-melanosomal domain, hTyrCtr (residues 19-469). Active hTyr is monomeric in detergent micelles suggesting no stable interactions between protein molecules. Both, hTyr and hTyrCtr, exhibited similar enzymatic activity and ligand affinity in L-DOPA and L-Tyrosine reactions. In addition, expression in larvae is a scalable process that will allow high yield protein production. Thus, larval production of enzymatically active human tyrosinase potentially could be a useful tool in developing a cure for OCA1.
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Qiu B, Ma T, Peng C, Zheng X, Yang J. Identification of Five Novel Variants in Chinese Oculocutaneous Albinism by Targeted Next-Generation Sequencing. Genet Test Mol Biomarkers 2018; 22:252-258. [PMID: 29437493 DOI: 10.1089/gtmb.2017.0211] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The diagnosis of oculocutaneous albinism (OCA) is established using clinical signs and symptoms. OCA is, however, a highly genetically heterogeneous disease with mutations identified in at least nineteen unique genes, many of which produce overlapping phenotypic traits. Thus, differentiating genetic OCA subtypes for diagnoses and genetic counseling is challenging, based on clinical presentation alone, and would benefit from a comprehensive molecular diagnostic. AIM To develop and validate a more comprehensive, targeted, next-generation-sequencing-based diagnostic for the identification of OCA-causing variants. MATERIALS AND METHODS The genomic DNA samples from 28 OCA probands were analyzed by targeted next-generation sequencing (NGS), and the candidate variants were confirmed through Sanger sequencing. RESULTS We observed mutations in the TYR, OCA2, and SLC45A2 genes in 25/28 (89%) patients with OCA. We identified 38 pathogenic variants among these three genes, including 5 novel variants: c.1970G>T (p.Gly657Val), c.1669A>C (p.Thr557Pro), c.2339-2A>C, and c.1349C>G (p.Thr450Arg) in OCA2; c.459_470delTTTTGCTGCCGA (p.Ala155_Phe158del) in SLC45A2. CONCLUSION Our findings expand the mutational spectrum of OCA in the Chinese population, and the assay we developed should be broadly useful as a molecular diagnostic, and as an aid for genetic counseling for OCA patients.
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Affiliation(s)
- Biyuan Qiu
- 1 Medical Technology College, Chengdu University of Traditional Chinese Medicine of China , Chengdu, Sichuan, P.R. China
| | - Tao Ma
- 2 Prenatal Diagnosis Center, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital , Chengdu, Sichuan, P.R. China .,3 Department of Gynecology & Obstetrics, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital , Chengdu, Sichuan, P.R. China
| | - Chunyan Peng
- 4 School of Medicine, University of Electronic Science and Technology of China , Chengdu, Sichuan, P.R. China
| | - Xiaoqin Zheng
- 1 Medical Technology College, Chengdu University of Traditional Chinese Medicine of China , Chengdu, Sichuan, P.R. China
| | - Jiyun Yang
- 2 Prenatal Diagnosis Center, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital , Chengdu, Sichuan, P.R. China .,4 School of Medicine, University of Electronic Science and Technology of China , Chengdu, Sichuan, P.R. China .,5 Sichuan Provincial Key Laboratory for Human Disease Gene Study, Hospital of the University of Electronic Science and Technology of China and Sichuan Provincial People's Hospital , Chengdu, Sichuan, P.R. China
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16
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Identification of a functionally significant tri-allelic genotype in the Tyrosinase gene (TYR) causing hypomorphic oculocutaneous albinism (OCA1B). Sci Rep 2017; 7:4415. [PMID: 28667292 PMCID: PMC5493628 DOI: 10.1038/s41598-017-04401-5] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 05/05/2017] [Indexed: 12/04/2022] Open
Abstract
Oculocutaneous albinism (OCA) and ocular albinism (OA) are inherited disorders of melanin biosynthesis, resulting in loss of pigment and severe visual deficits. OCA encompasses a range of subtypes with overlapping, often hypomorphic phenotypes. OCA1 is the most common cause of albinism in European populations and is inherited through autosomal recessive mutations in the Tyrosinase (TYR) gene. However, there is a high level of reported missing heritability, where only a single heterozygous mutation is found in TYR. This is also the case for other OCA subtypes including OCA2 caused by mutations in the OCA2 gene. Here we have interrogated the genetic cause of albinism in a well phenotyped, hypomorphic albinism population by sequencing a broad gene panel and performing segregation studies on phenotyped family members. Of eighteen probands we can confidently diagnose three with OA and OCA2, and one with a PAX6 mutation. Of six probands with only a single heterozygous mutation in TYR, all were found to have the two common variants S192Y and R402Q. Our results suggest that a combination of R402Q and S192Y with a deleterious mutation in a ‘tri-allelic genotype’ can account for missing heritability in some hypomorphic OCA1 albinism phenotypes.
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Shahzad M, Yousaf S, Waryah YM, Gul H, Kausar T, Tariq N, Mahmood U, Ali M, Khan MA, Waryah AM, Shaikh RS, Riazuddin S, Ahmed ZM. Molecular outcomes, clinical consequences, and genetic diagnosis of Oculocutaneous Albinism in Pakistani population. Sci Rep 2017; 7:44185. [PMID: 28266639 PMCID: PMC5339803 DOI: 10.1038/srep44185] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 02/03/2017] [Indexed: 12/31/2022] Open
Abstract
Nonsyndromic oculocutaneous Albinism (nsOCA) is clinically characterized by the loss of pigmentation in the skin, hair, and iris. OCA is amongst the most common causes of vision impairment in children. To date, pathogenic variants in six genes have been identified in individuals with nsOCA. Here, we determined the identities, frequencies, and clinical consequences of OCA alleles in 94 previously unreported Pakistani families. Combination of Sanger and Exome sequencing revealed 38 alleles, including 22 novel variants, segregating with nsOCA phenotype in 80 families. Variants of TYR and OCA2 genes were the most common cause of nsOCA, occurring in 43 and 30 families, respectively. Twenty-two novel variants include nine missense, four splice site, two non-sense, one insertion and six gross deletions. In vitro studies revealed retention of OCA proteins harboring novel missense alleles in the endoplasmic reticulum (ER) of transfected cells. Exon-trapping assays with constructs containing splice site alleles revealed errors in splicing. As eight alleles account for approximately 56% (95% CI: 46.52–65.24%) of nsOCA cases, primarily enrolled from Punjab province of Pakistan, hierarchical strategies for variant detection would be feasible and cost-efficient genetic tests for OCA in families with similar origin. Thus, we developed Tetra-primer ARMS assays for rapid, reliable, reproducible and economical screening of most of these common alleles.
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Affiliation(s)
- Mohsin Shahzad
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Sairah Yousaf
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD, USA.,Institute of Molecular Biology &Biotechnology, Bahauddin Zakariya University, Multan, Pakistan
| | - Yar M Waryah
- Molecular Biology &Genetics Department, Medical Research Center, Liaquat University of Medical &Health Sciences, Jamshoro, Pakistan
| | - Hadia Gul
- Gomal Centre of Biochemistry and Biotechnology, Gomal University, D.I. Khan, Pakistan
| | - Tasleem Kausar
- Institute of Molecular Biology &Biotechnology, Bahauddin Zakariya University, Multan, Pakistan
| | - Nabeela Tariq
- Institute of Molecular Biology &Biotechnology, Bahauddin Zakariya University, Multan, Pakistan
| | - Umair Mahmood
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Muhammad Ali
- Government College University, Faisalabad, Pakistan
| | - Muzammil A Khan
- Gomal Centre of Biochemistry and Biotechnology, Gomal University, D.I. Khan, Pakistan
| | - Ali M Waryah
- Molecular Biology &Genetics Department, Medical Research Center, Liaquat University of Medical &Health Sciences, Jamshoro, Pakistan
| | - Rehan S Shaikh
- Institute of Molecular Biology &Biotechnology, Bahauddin Zakariya University, Multan, Pakistan
| | - Saima Riazuddin
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD, USA
| | - Zubair M Ahmed
- Department of Otorhinolaryngology Head and Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD, USA
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Yue LM, Lee J, Lü ZR, Yang JM, Ye ZM, Park YD. Effect of Cd 2+ on tyrosinase: Integration of inhibition kinetics with computational simulation. Int J Biol Macromol 2017; 94:836-844. [DOI: 10.1016/j.ijbiomac.2016.09.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 08/30/2016] [Accepted: 09/01/2016] [Indexed: 01/02/2023]
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Integration of Next Generation Sequencing and EPR Analysis to Uncover Molecular Mechanism Underlying Shell Color Variation in Scallops. PLoS One 2016; 11:e0161876. [PMID: 27563719 PMCID: PMC5001709 DOI: 10.1371/journal.pone.0161876] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Accepted: 08/12/2016] [Indexed: 12/05/2022] Open
Abstract
The Yesso scallop Patinopecten yessoensis displays polymorphism in shell colors, which is of great interest for the scallop industry. To identify genes involved in the shell coloration, in the present study, we investigate the transcriptome differences by Illumina digital gene expression (DGE) analysis in two extreme color phenotypes, Red and White. Illumina sequencing yields a total of 62,715,364 clean sequence reads, and more than 85% reads are mapped into our previously sequenced transcriptome. There are 25 significantly differentially expressed genes between Red and White scallops. EPR (Electron paramagnetic resonance) analysis has identified EPR spectra of pheomelanin and eumelanin in the red shells, but not in the white shells. Compared to the Red scallops, the White scallops have relatively higher mRNA expression in tyrosinase genes, but lower expression in other melanogensis-associated genes. Meantime, the relatively lower tyrosinase protein and decreased tyrosinase activity in White scallops are suggested to be associated with the lack of melanin in the white shells. Our findings highlight the functional roles of melanogensis-associated genes in the melanization process of scallop shells, and shed new lights on the transcriptional and post-transcriptional mechanisms in the regulation of tyrosinase activity during the process of melanin synthesis. The present results will assist our molecular understanding of melanin synthesis underlying shell color polymorphism in scallops, as well as other bivalves, and also help the color-based breeding in shellfish aquaculture.
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Lai X, Soler-Lopez M, Wichers HJ, Dijkstra BW. Large-Scale Recombinant Expression and Purification of Human Tyrosinase Suitable for Structural Studies. PLoS One 2016; 11:e0161697. [PMID: 27551823 PMCID: PMC4994950 DOI: 10.1371/journal.pone.0161697] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 08/10/2016] [Indexed: 12/02/2022] Open
Abstract
Human tyrosinase (TYR) is a glycoprotein that initiates the first two reactions in the melanin biosynthesis pathway. Mutations in its encoding gene cause Oculocutaneous Albinism type I (OCA1), the most severe form of albinism, which is a group of autosomal recessive disorders characterized by reduced or absent production of melanin in skin, hair and eyes. Despite extensive structural and characterization studies of its homologues in lower eukaryotic organisms, the catalytic mechanism of human TYR and the molecular basis of OCA1 are largely unknown. In this work, we have carried out a large-scale recombinant expression of TYR that has enabled us to obtain high yields of pure and active protein, required for crystallization trials and screening of skin whitening agents, which is highly demanded in the cosmetic industry. Addition of an N-terminal honeybee melittin signal peptide for secretion of the produced protein into the (protein-free) medium, as well as a cleavable His-tag at the C-terminus, was crucial for increasing the yield of pure protein. We have successfully crystallized two TYR variants, in both glycosylated and deglycosylated forms, showing preliminary X-ray diffraction patterns at 3.5 Å resolution. Hence, we have established an expression and purification protocol suitable for the crystal structure determination of human TYR, which will give unique atomic insight into the nature and conformation of the residues that shape the substrate binding pocket that will ultimately lead to efficient compound design.
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Affiliation(s)
- Xuelei Lai
- Laboratory of Biophysical Chemistry, University of Groningen, Groningen, The Netherlands
- ESRF-The European Synchrotron, Grenoble, France
| | | | - Harry J. Wichers
- Laboratory of Food Chemistry, Wageningen University, Wageningen, The Netherlands
| | - Bauke W. Dijkstra
- Laboratory of Biophysical Chemistry, University of Groningen, Groningen, The Netherlands
- * E-mail:
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Polishchuk EV, Polishchuk RS. The emerging role of lysosomes in copper homeostasis. Metallomics 2016; 8:853-62. [PMID: 27339113 DOI: 10.1039/c6mt00058d] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The lysosomal system operates as a focal point where a number of important physiological processes such as endocytosis, autophagy and nutrient sensing converge. One of the key functions of lysosomes consists of regulating the metabolism/homeostasis of metals. Metal-containing components are carried to the lysosome through incoming membrane flows, while numerous transporters allow metal ions to move across the lysosome membrane. These properties enable lysosomes to direct metal fluxes to the sites where metal ions are either used by cellular components or sequestered. Copper belongs to a group of metals that are essential for the activity of vitally important enzymes, although it is toxic when in excess. Thus, copper uptake, supply and intracellular compartmentalization have to be tightly regulated. An increasing number of publications have indicated that these processes involve lysosomes. Here we review studies that reveal the expanding role of the lysosomal system as a hub for the control of Cu homeostasis and for the regulation of key Cu-dependent processes in health and disease.
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Affiliation(s)
- Elena V Polishchuk
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei 34, Pozzuoli (NA), 80078, Italy.
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Jonnalagadda M, Norton H, Ozarkar S, Kulkarni S, Ashma R. Association of genetic variants with skin pigmentation phenotype among populations of west Maharashtra, India. Am J Hum Biol 2016; 28:610-8. [PMID: 26918427 DOI: 10.1002/ajhb.22836] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/23/2015] [Accepted: 01/07/2016] [Indexed: 01/25/2023] Open
Abstract
OBJECTIVES South Asians exhibit extensive variation in skin melanin index (MI) which is observed across the broader region of South Asia as well as within restricted geographic regions. However, the genetic variants associated with variation in the skin pigmentation phenotype are poorly understood in these populations. The present study examines the association between MI measures and genetic variants from 5 candidate pigmentation genes among 533 individuals representing 6 populations of West Maharashtra. METHODS Associations between five single nucleotide polymorphisms (SNPs) known to play a role in pigmentation (rs1426654-SLC24A5, rs1042602-TYR, rs16891982-SLC45A2, rs6058017-ASIP, and rs642742-KITLG) and MI measures were tested using standard one-way analysis of variance (ANOVA) within each population. Multiple linear regression was used to test the effects of these SNPs in the full West Maharashtra sample using sex, age, and population or social group as covariates. RESULTS rs1426654 showed significant association with MI in all six study populations (P < 0.01). Association tests using sex, age, and population as covariates showed rs1426654 and rs1042602 to be significantly (P < 0.01) associated with lighter skin pigmentation in West Maharashtra as a whole. By contrast, when social group was added as a covariate instead of population, rs1426654, rs1042602, and rs16891982 were significantly (P < 0.01) associated with lighter skin pigmentation. CONCLUSIONS Only rs1426654 is significantly associated with MI in each individual population; however, rs1426654, rs1042602, and rs16891982 are significantly associated with pigmentation in the broader West Maharashtra region after controlling for population and social group, with rs1426654 (SLC24A5) explaining the majority of the observed variation. Am. J. Hum. Biol. 28:610-618, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Manjari Jonnalagadda
- Department of Anthropology, Savitribai Phule Pune University (Formerly University of Pune), Pune, Maharashtra, India
| | - Heather Norton
- Department of Anthropology, University of Cincinnati, Cincinnati, Ohio
| | - Shantanu Ozarkar
- Department of Anthropology, Savitribai Phule Pune University (Formerly University of Pune), Pune, Maharashtra, India
| | - Shaunak Kulkarni
- Department of Anthropology, Savitribai Phule Pune University (Formerly University of Pune), Pune, Maharashtra, India
| | - Richa Ashma
- Department of Zoology, Savitribai Phule Pune University (Formerly University of Pune), Pune, Maharashtra, India.
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Wei AH, Zang DJ, Zhang Z, Yang XM, Li W. Prenatal Genotyping of Four Common Oculocutaneous Albinism Genes in 51 Chinese Families. J Genet Genomics 2015; 42:279-86. [DOI: 10.1016/j.jgg.2015.05.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/17/2015] [Accepted: 05/18/2015] [Indexed: 11/28/2022]
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Ghodsinejad Kalahroudi V, Kamalidehghan B, Arasteh Kani A, Aryani O, Tondar M, Ahmadipour F, Chung LY, Houshmand M. Two novel tyrosinase (TYR) gene mutations with pathogenic impact on oculocutaneous albinism type 1 (OCA1). PLoS One 2014; 9:e106656. [PMID: 25216246 PMCID: PMC4162572 DOI: 10.1371/journal.pone.0106656] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2014] [Accepted: 08/06/2014] [Indexed: 11/19/2022] Open
Abstract
Oculocutaneous albinism (OCA) is a heterogeneous group of autosomal recessive disorders resulting from mutations of the tyrosinase (TYR) gene and presents with either complete or partial absence of pigment in the skin, hair and eyes due to a defect in an enzyme involved in the production of melanin. In this study, mutations in the TYR gene of 30 unrelated Iranian OCA1 patients and 100 healthy individuals were examined using PCR-sequencing. Additionally, in order to predict the possible effects of new mutations on the structure and function of tyrosinase, these mutations were analyzed by SIFT, PolyPhen and I-Mutant 2 software. Here, two new pathogenic p.C89S and p.H180R mutations were detected in two OCA1 patients. Moreover, the R402Q and S192Y variants, which are common non-pathogenic polymorphisms, were detected in 17.5% and 35% of the patients, respectively. The outcome of this study has extended the genotypic spectrum of OCA1 patients, which paves the way for more efficient carrier detection and genetic counseling.
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Affiliation(s)
- Vadieh Ghodsinejad Kalahroudi
- Department of Biology, Kharazmi University, Tehran, Iran
- Department of Medical Genetics, Special Medical Center, Tehran, Iran
| | - Behnam Kamalidehghan
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | | | - Omid Aryani
- Department of Medical Genetics, Special Medical Center, Tehran, Iran
| | - Mahdi Tondar
- Department of Medical Genetics, Special Medical Center, Tehran, Iran
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, D.C., United States of America
| | - Fatemeh Ahmadipour
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Lip Yong Chung
- Department of Pharmacy, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Massoud Houshmand
- Department of Medical Genetics, Special Medical Center, Tehran, Iran
- Department of Medical Genetics, National Institute for Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
- * E-mail:
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Melanins: Skin Pigments and Much More—Types, Structural Models, Biological Functions, and Formation Routes. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/498276] [Citation(s) in RCA: 277] [Impact Index Per Article: 27.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This review presents a general view of all types of melanin in all types of organisms. Melanin is frequently considered just an animal cutaneous pigment and is treated separately from similar fungal or bacterial pigments. Similarities concerning the phenol precursors and common patterns in the formation routes are discussed. All melanins are formed in a first enzymatically-controlled phase, generally a phenolase, and a second phase characterized by an uncontrolled polymerization of the oxidized intermediates. In that second phase, quinones derived from phenol oxidation play a crucial role. Concerning functions, all melanins show a common feature, a protective role, but they are not merely photoprotective pigments against UV sunlight. In pathogenic microorganisms, melanization becomes a virulence factor since melanin protects microbial cells from defense mechanisms in the infected host. In turn, some melanins are formed in tissues where sunlight radiation is not a potential threat. Then, their redox, metal chelating, or free radical scavenging properties are more important than light absorption capacity. These pigments sometimes behave as a double-edged sword, and inhibition of melanogenesis is desirable in different cells. Melanin biochemistry is an active field of research from dermatological, biomedical, cosmetical, and microbiological points of view, as well as fruit technology.
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Guo X, Zhang T, Hu Z, Zhang Y, Shi Z, Wang Q, Cui Y, Wang F, Zhao H, Chen Y. Efficient RNA/Cas9-mediated genome editing in Xenopus tropicalis. Development 2014; 141:707-14. [PMID: 24401372 DOI: 10.1242/dev.099853] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
For the emerging amphibian genetic model Xenopus tropicalis targeted gene disruption is dependent on zinc-finger nucleases (ZFNs) or transcription activator-like effector nucleases (TALENs), which require either complex design and selection or laborious construction. Thus, easy and efficient genome editing tools are still highly desirable for this species. Here, we report that RNA-guided Cas9 nuclease resulted in precise targeted gene disruption in all ten X. tropicalis genes that we analyzed, with efficiencies above 45% and readily up to 100%. Systematic point mutation analyses in two loci revealed that perfect matches between the spacer and the protospacer sequences proximal to the protospacer adjacent motif (PAM) were essential for Cas9 to cleave the target sites in the X. tropicalis genome. Further study showed that the Cas9 system could serve as an efficient tool for multiplexed genome engineering in Xenopus embryos. Analysis of the disruption of two genes, ptf1a/p48 and tyrosinase, indicated that Cas9-mediated gene targeting can facilitate direct phenotypic assessment in X. tropicalis embryos. Finally, five founder frogs from targeting of either elastase-T1, elastase-T2 or tyrosinase showed highly efficient transmission of targeted mutations into F1 embryos. Together, our data demonstrate that the Cas9 system is an easy, efficient and reliable tool for multiplex genome editing in X. tropicalis.
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Affiliation(s)
- Xiaogang Guo
- Key Laboratory of Regenerative Biology, South China Institute for Stem Cell Biology and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, Guangdong 510530, China
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Mártinez-García M, Montoliu L. Albinism in Europe. J Dermatol 2013; 40:319-24. [DOI: 10.1111/1346-8138.12170] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2013] [Accepted: 03/17/2013] [Indexed: 11/27/2022]
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Simeonov DR, Wang X, Wang C, Sergeev Y, Dolinska M, Bower M, Fischer R, Winer D, Dubrovsky G, Balog JZ, Huizing M, Hart R, Zein WM, Gahl WA, Brooks BP, Adams DR. DNA variations in oculocutaneous albinism: an updated mutation list and current outstanding issues in molecular diagnostics. Hum Mutat 2013; 34:827-35. [PMID: 23504663 DOI: 10.1002/humu.22315] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 03/08/2013] [Indexed: 12/20/2022]
Abstract
Oculocutaneous albinism (OCA) is a rare genetic disorder of melanin synthesis that results in hypopigmented hair, skin, and eyes. There are four types of OCA caused by mutations in TYR (OCA-1), OCA2 (OCA-2), TYRP1 (OCA-3), or SLC45A2 (OCA-4). Here we report 22 novel mutations in the OCA genes; 14 from a cohort of 61 patients seen as part of the NIH OCA Natural History Study and eight from a prior study at the University of Minnesota. We also include a comprehensive list of almost 600 previously reported OCA mutations along with ethnicity information, carrier frequencies, and in silico pathogenicity predictions as a supplement. In addition to discussing the clinical and molecular features of OCA, we address the cases of apparent missing heritability. In our cohort, 26% of patients did not have two mutations in a single OCA gene. We demonstrate the utility of multiple detection methods to reveal mutations missed by Sanger sequencing. Finally, we review the TYR p.R402Q temperature-sensitive variant and confirm its association with cases of albinism with only one identifiable TYR mutation.
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Affiliation(s)
- Dimitre R Simeonov
- National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
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Roffler-Tarlov S, Liu JH, Naumova EN, Bernal-Ayala MM, Mason CA. L-Dopa and the albino riddle: content of L-Dopa in the developing retina of pigmented and albino mice. PLoS One 2013; 8:e57184. [PMID: 23526936 PMCID: PMC3602463 DOI: 10.1371/journal.pone.0057184] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 01/18/2013] [Indexed: 01/11/2023] Open
Abstract
Background The absence or deficiency of melanin as in albinos, has detrimental effects on retinal development that include aberrant axonal projections from eye to brain and impaired vision. In pigmented retinal pigment epithelium (RPE), dihydroxyphenalanine (L-Dopa), an intermediate in the synthetic path for melanin, has been hypothesized to regulate the tempo of neurogenesis. The time course of expression of retinal L-Dopa, whether it is harbored exclusively in the RPE, the extent of deficiency in albinos compared to isogenic controls, and whether L-Dopa can be restored if exogenously delivered to the albino have been unknown. Methodology/Principal Findings L-Dopa and catecholamines including dopamine extracted from retinas of pigmented (C57BL/6J) and congenic albino (C57BL/6J-tyrc2j) mice, were measured throughout development beginning at E10.5 and at maturity. L-Dopa, but not dopamine nor any other catecholamine, appears in pigmented retina as soon as tyrosinase is expressed in RPE at E10.5. In pigmented retina, L-Dopa content increases throughout pre- and postnatal development until the end of the first postnatal month after which it declines sharply. This time course reflects the onset and completion of retinal development. L-Dopa is absent from embryonic albino retina and is greatly reduced in postnatal albino retina compared to pigmented retina. Dopamine is undetectable in both albino and pigmented retinas until after the postnatal expression of the neuronal enzyme tyrosine hydroxylase. If provided to pregnant albino mothers, L-Dopa accumulates in the RPE of the fetuses. Conclusions L-Dopa in pigmented RPE is most abundant during development after which content declines. This L-Dopa is not converted to dopamine. L-Dopa is absent or at low levels in albino retina and can be restored to the RPE by administration in utero. These findings further implicate L-Dopa as a factor in the RPE that could influence development, and demonstrate that administration of L-Dopa could be a means to rescue developmental abnormalities characteristic of albinos.
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Affiliation(s)
- Suzanne Roffler-Tarlov
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts, United States of America.
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Wei AH, Zang DJ, Zhang Z, Liu XZ, He X, Yang L, Wang Y, Zhou ZY, Zhang MR, Dai LL, Yang XM, Li W. Exome sequencing identifies SLC24A5 as a candidate gene for nonsyndromic oculocutaneous albinism. J Invest Dermatol 2013; 133:1834-40. [PMID: 23364476 DOI: 10.1038/jid.2013.49] [Citation(s) in RCA: 81] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Oculocutaneous albinism (OCA) is a heterogeneous and autosomal recessive disorder with hypopigmentation in the eye, hair, and skin color. Four genes, TYR, OCA2, TYRP1, and SLC45A2, have been identified as causative genes for nonsyndromic OCA1-4, respectively. The genetic identity of OCA5 locus on 4q24 is unknown. Additional unknown OCA genes may exist as at least 5% of OCA patients have not been characterized during mutational screening in several populations. We used exome sequencing with a family-based recessive mutation model to determine that SLC24A5 is a previously unreported candidate gene for nonsyndromic OCA, which we designate as OCA6. Two deleterious mutations in this patient, c.591G>A and c.1361insT, were identified. We found apparent increase of immature melanosomes and less mature melanosomes in the patient's skin melanocytes. However, no defects in the platelet dense granules were observed, excluding typical Hermansky-Pudlak syndrome (HPS), a well-known syndromic OCA. Moreover, the SLC24A5 protein was reduced in steady-state levels in mouse HPS mutants with deficiencies in BLOC-1 and BLOC-2. Our results suggest that SLC24A5 is a previously unreported nonsyndromic OCA candidate gene and that the SLC24A5 transporter is transported into mature melanosomes by HPS protein complexes.
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Affiliation(s)
- Ai-Hua Wei
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
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Hawkes JE, Cassidy PB, Manga P, Boissy RE, Goldgar D, Cannon-Albright L, Florell SR, Leachman SA. Report of a novel OCA2 gene mutation and an investigation of OCA2 variants on melanoma risk in a familial melanoma pedigree. J Dermatol Sci 2013; 69:30-7. [PMID: 23103111 PMCID: PMC4775076 DOI: 10.1016/j.jdermsci.2012.09.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2011] [Revised: 08/26/2012] [Accepted: 09/27/2012] [Indexed: 11/21/2022]
Abstract
BACKGROUND Oculocutaneous albinism type 2 (OCA2) is caused by mutations of the OCA2 gene. Individuals affected by OCA2 as well as other types of albinism are at a significantly increased risk for sun-induced skin-cancers, including malignant melanoma (MM). OBJECTIVE To identify the molecular etiology of oculocutaneous albinism in a previously uncharacterized melanoma pedigree and to investigate the relationship between two OCA2 variants and melanoma predisposition in this pedigree. METHODS DNA and RNA were isolated from the peripheral blood of seven patients in a familial melanoma pedigree. Electron microscopy was performed on the individual with clinical oculocutaneous albinism. OCA2, TYRP1, MC1R, CDKN2A/p16, CDKN2A/p19ARF, and CDK4 genes were sequenced in affected individuals. The relationship between OCA2 variants and melanoma was assessed using a pedigree likelihood-based method. RESULTS The proband was determined to be an OCA2 compound heterozygous mutation carrier with a previously reported conservative missense mutation (V443I) and a novel non-conservative missense mutation (L734R). The pedigree contained individuals diagnosed with both cutaneous and iris melanoma. Based on co-segregation analysis, the odds of these OCA2 variants being high penetrance loci for melanoma was: 1.3-to-1 if we include the iris melanoma as affected and 6.5-to-1 if we only consider cutaneous melanoma as affected. CONCLUSION The discovery of this novel OCA2 variant adds to the body of evidence on the detrimental effects of OCA2 gene mutations on pigmentation, supports existing GWAS data on the relevance of the OCA2 gene in melanoma predisposition, and may ultimately assist in the development of targeted molecular therapies in the treatment of OCA and melanoma.
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Affiliation(s)
- Jason E. Hawkes
- Huntsman Cancer Institute and Department of Dermatology, University of Utah Health Sciences Center, Salt Lake City, UT, USA
| | - Pamela B. Cassidy
- Huntsman Cancer Institute and Department of Dermatology, University of Utah Health Sciences Center, Salt Lake City, UT, USA
- Department of Medicinal Chemistry L.S. Skagg's Pharmacy, University of Utah Health Sciences Center, Salt Lake City, UT, USA
| | - Prashiela Manga
- Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY, USA
| | - Raymond E. Boissy
- Department of Dermatology, University of Cincinnati, Cincinnati, OH, USA
| | - David Goldgar
- Huntsman Cancer Institute and Department of Dermatology, University of Utah Health Sciences Center, Salt Lake City, UT, USA
| | - Lisa Cannon-Albright
- Department of Biomedical Informatics, Huntsman Cancer Institute, Salt Lake City, UT, USA
| | - Scott R. Florell
- Huntsman Cancer Institute and Department of Dermatology, University of Utah Health Sciences Center, Salt Lake City, UT, USA
| | - Sancy A. Leachman
- Huntsman Cancer Institute and Department of Dermatology, University of Utah Health Sciences Center, Salt Lake City, UT, USA
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Ishibashi S, Cliffe R, Amaya E. Highly efficient bi-allelic mutation rates using TALENs in Xenopus tropicalis. Biol Open 2012; 1:1273-6. [PMID: 23408158 PMCID: PMC3558749 DOI: 10.1242/bio.20123228] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 10/09/2012] [Indexed: 01/01/2023] Open
Abstract
In the past decade, Xenopus tropicalis has emerged as a powerful new amphibian genetic model system, which offers all of the experimental advantages of its larger cousin, Xenopus laevis. Here we investigated the efficiency of transcription activator-like effector nucleases (TALENs) for generating targeted mutations in endogenous genes in X. tropicalis. For our analysis we targeted the tyrosinase (oculocutaneous albinism IA) (tyr) gene, which is required for the production of skin pigments, such as melanin. We injected mRNA encoding TALENs targeting the first exon of the tyr gene into two-cell-stage embryos. Surprisingly, we found that over 90% of the founder animals developed either partial or full albinism, suggesting that the TALENs induced bi-allelic mutations in the tyr gene at very high frequency in the F0 animals. Furthermore, mutations tyr gene were efficiently transmitted into the F1 progeny, as evidenced by the generation of albino offspring. These findings have far reaching implications in our quest to develop efficient reverse genetic approaches in this emerging amphibian model.
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Affiliation(s)
- Shoko Ishibashi
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester , Oxford Road, Manchester M13 9PT , UK
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Omar R, Idris SS, Meng CK, Knight VF. Management of visual disturbances in albinism: a case report. J Med Case Rep 2012; 6:316. [PMID: 22992390 PMCID: PMC3459795 DOI: 10.1186/1752-1947-6-316] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 08/03/2012] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION A number of vision defects have been reported in association with albinism, such as photophobia, nystagmus and astigmatism. In many cases only prescription sunglasses are prescribed. In this report, the effectiveness of low-vision rehabilitation in albinism, which included prescription of multiple visual aids, is discussed. CASE PRESENTATION We present the case of a 21-year-old Asian woman with albinism and associated vision defects. Her problems were blurring of distant vision, glare and her dissatisfaction with her current auto-focus spectacle-mounted telescope device, which she reported as being heavy as well as cosmetically unacceptable. We describe how low-vision rehabilitation using multiple visual aids, namely spectacles, special iris-tinted contact lenses with clear pupils, and bi-level telemicroscopic apparatus devices improved her quality of life. Subsequent to rehabilitation our patient is happier and continues to use the visual aids. CONCLUSIONS Contact lenses with a special iris tint and clear pupil area are useful aids to reduce the glare experienced by albinos. Bi-level telemicroscopic apparatus telemicroscopes fitted onto our patient's prescription spectacles were cosmetically acceptable and able to improve her distance vision. As a result these low-vision rehabilitation approaches improved the quality of life of our albino patient.
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Affiliation(s)
- Rokiah Omar
- Optometry and Visual Science Program, School of Healthcare Sciences, Faculty of Health Sciences, Universiti Kebangsaan Malaysia, Jalan Raja Muda Abdul Aziz, 50300, Kuala Lumpur, Malaysia.
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Dong C, Wang H, Xue L, Dong Y, Yang L, Fan R, Yu X, Tian X, Ma S, Smith GW. Coat color determination by miR-137 mediated down-regulation of microphthalmia-associated transcription factor in a mouse model. RNA (NEW YORK, N.Y.) 2012; 18:1679-1686. [PMID: 22847819 PMCID: PMC3425782 DOI: 10.1261/rna.033977.112] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2012] [Accepted: 06/11/2012] [Indexed: 05/31/2023]
Abstract
Coat color is a key economic trait in wool-producing species. Color development and pigmentation are controlled by complex mechanisms in animals. Here, we report the first production of an altered coat color by overexpression of miR-137 in transgenic mice. Transgenic mice overexpressing miR-137 developed a range of coat color changes from dark black to light color. Molecular analyses of the transgenic mice showed decreased expression of the major target gene termed MITF and its downstream genes, including TYR, TYRP1, and TYRP2. We also showed that melanogenesis altered by miR-137 is distinct from that affected by UV radiation in transgenic mice. Our study provides the first mouse model for the study of coat color controlled by miRNAs in animals and may have important applications in wool production.
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Affiliation(s)
- Changsheng Dong
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, PC 030801, Shanxi, China.
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El-Sadek MM, Hassan SY, Abdelwahab HE, Yacout GA. Synthesis of new 1,3,4-thiadiazole and 1,2,3,4-oxathiadiazole derivatives from carbohydrate precursors and study of their effect on tyrosinase enzyme. Molecules 2012; 17:8378-96. [PMID: 22785266 PMCID: PMC6268412 DOI: 10.3390/molecules17078378] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 07/10/2012] [Accepted: 07/10/2012] [Indexed: 11/16/2022] Open
Abstract
5-(1,2,3,4-Tetrahydroxybutyl)-2-methylfuran-3-carbohydrazide (2) was condensed with a variety of ketones to afford carbohydrazide derivatives 3-6. Acetylation of 3-5 afforded the acetyl derivatives 7-9, while periodate oxidation of 3-6 afforded the formyl derivatives 10-13. Acid catalyzed condensation of thiosemicarbazide or o-tolylthiosemicarbazide with the prepared aldehydes 10-12 gave thiosemicarbazone derivatives 14-19. Cyclization of the latter with acetic anhydride afforded 4,5-dihydro-1,3,4-thiadiazolyl derivatives 20-25. On the other hand, condensation of p-tosylhydrazine with the prepared aldehydes 10-12 afforded p-tosylhydrazone derivatives 26-28. Cyclization of 26-28 with acetic anhydride afforded 1,2,3,4-oxathiadiazole derivatives 29-31 respectively. Moreover, the obtained results regarding to the effect of some of the prepared compounds on tyrosinase enzyme showed that the majority of these compounds having an inhibitory effect; especially compounds 12, 16, 17, and 28.
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Affiliation(s)
- Mohamed M. El-Sadek
- Chemistry Department, Faculty of Science, Alexandria University, Alexandria 21231, Egypt; (S.Y.H.); (H.E.A.)
- Author to whom correspondence should be addressed; ; Tel.: +20-01-006-544-617; Fax: +20-3-5932-488
| | - Seham Y. Hassan
- Chemistry Department, Faculty of Science, Alexandria University, Alexandria 21231, Egypt; (S.Y.H.); (H.E.A.)
| | - Huda E. Abdelwahab
- Chemistry Department, Faculty of Science, Alexandria University, Alexandria 21231, Egypt; (S.Y.H.); (H.E.A.)
| | - Galila A. Yacout
- Biochemistry Department, Faculty of Science, Alexandria University, Alexandria 21231, Egypt;
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C-terminus glycans with critical functional role in the maturation of secretory glycoproteins. PLoS One 2011; 6:e19979. [PMID: 21625599 PMCID: PMC3097235 DOI: 10.1371/journal.pone.0019979] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 04/21/2011] [Indexed: 02/07/2023] Open
Abstract
The N-glycans of membrane glycoproteins are mainly exposed to the extracellular space. Human tyrosinase is a transmembrane glycoprotein with six or seven bulky N-glycans exposed towards the lumen of subcellular organelles. The central active site region of human tyrosinase is modeled here within less than 2.5 Å accuracy starting from Streptomyces castaneoglobisporus tyrosinase. The model accounts for the last five C-terminus glycosylation sites of which four are occupied and indicates that these cluster in two pairs--one in close vicinity to the active site and the other on the opposite side. We have analyzed and compared the roles of all tyrosinase N-glycans during tyrosinase processing with a special focus on the proximal to the active site N-glycans, s6:N337 and s7:N371, versus s3:N161 and s4:N230 which decorate the opposite side of the domain. To this end, we have constructed mutants of human tyrosinase in which its seven N-glycosylation sites were deleted. Ablation of the s6:N337 and s7:N371 sites arrests the post-translational productive folding process resulting in terminally misfolded mutants subjected to degradation through the mannosidase driven ERAD pathway. In contrast, single mutants of the other five N-glycans located either opposite to the active site or into the N-terminus Cys1 extension of tyrosinase are temperature-sensitive mutants and recover enzymatic activity at the permissive temperature of 31°C. Sites s3 and s4 display selective calreticulin binding properties. The C-terminus sites s7 and s6 are critical for the endoplasmic reticulum retention and intracellular disposal. Results herein suggest that individual N-glycan location is critical for the stability, regional folding control and secretion of human tyrosinase and explains some tyrosinase gene missense mutations associated with oculocutaneous albinism type I.
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Delevoye C, Giordano F, van Niel G, Raposo G. [Biogenesis of melanosomes - the chessboard of pigmentation]. Med Sci (Paris) 2011; 27:153-62. [PMID: 21382323 DOI: 10.1051/medsci/2011272153] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Melanosomes are lysosome-related organelles in retinal pigment epithelial cells and epidermal melanocytes in which melanin pigments are synthesized and stored. Melanosomes are generated by multistep processes in which an immature unpigmented organelle forms and then subsequently matures. Such maturation requires inter-organellar transport of protein cargos required for pigment synthesis but also recruitment of effector proteins necessary for the correct transport of melanosomes to the cell periphery. Several studies have started to unravel the main pathways and mechanisms exploited by melanosomal proteins involved in melanosome structure and melanin synthesis. A major unexpected finding seen early in melanosome biogenesis showed the similarities between the fibrillar sheets of premelanosomes and amyloid fibrils. Late steps of melanosome formation are dependent on pathways regulated by proteins encoded by genes mutated in genetic diseases such as the Hermansky-Pudlak Syndrom (HPS) and different types of albinism. Altogether the findings from the past recent years have started to unravel how specialized cells integrate unique and ubiquitous molecular mechanisms in subverting the endosomal system to generate cell-type specific structures and their associated functions. Further dissection of the melanosomal system will likely shed light not only on the biogenesis of lysosome-related organelles but also on general aspects of vesicular transport in the endosomal system.
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Affiliation(s)
- Cédric Delevoye
- Institut Curie, Centre de recherche, CNRS UMR144, 26, rue d'Ulm, 75248 Paris, France.
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Trantow CM, Cuffy TL, Fingert JH, Kuehn MH, Anderson MG. Microarray analysis of iris gene expression in mice with mutations influencing pigmentation. Invest Ophthalmol Vis Sci 2011; 52:237-48. [PMID: 20739468 DOI: 10.1167/iovs.10-5479] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Several ocular diseases involve the iris, notably including oculocutaneous albinism, pigment dispersion syndrome, and exfoliation syndrome. To screen for candidate genes that may contribute to the pathogenesis of these diseases, genome-wide iris gene expression patterns were comparatively analyzed from mouse models of these conditions. METHODS Iris samples from albino mice with a Tyr mutation, pigment dispersion-prone mice with Tyrp1 and Gpnmb mutations, and mice resembling exfoliation syndrome with a Lyst mutation were compared with samples from wild-type mice. All mice were strain (C57BL/6J), age (60 days old), and sex (female) matched. Microarrays were used to compare transcriptional profiles, and differentially expressed transcripts were described by functional annotation clustering using DAVID Bioinformatics Resources. Quantitative real-time PCR was performed to validate a subset of identified changes. RESULTS Compared with wild-type C57BL/6J mice, each disease context exhibited a large number of statistically significant changes in gene expression, including 685 transcripts differentially expressed in albino irides, 403 in pigment dispersion-prone irides, and 460 in exfoliative-like irides. CONCLUSIONS Functional annotation clusterings were particularly striking among the overrepresented genes, with albino and pigment dispersion-prone irides both exhibiting overall evidence of crystallin-mediated stress responses. Exfoliative-like irides from mice with a Lyst mutation showed overall evidence of involvement of genes that influence immune system processes, lytic vacuoles, and lysosomes. These findings have several biologically relevant implications, particularly with respect to secondary forms of glaucoma, and represent a useful resource as a hypothesis-generating dataset.
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Affiliation(s)
- Colleen M Trantow
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
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Holmström G, Eriksson U, Hellgren K, Larsson E. Optical coherence tomography is helpful in the diagnosis of foveal hypoplasia. Acta Ophthalmol 2010; 88:439-42. [PMID: 19493249 DOI: 10.1111/j.1755-3768.2009.01533.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE To investigate whether optical coherence tomography (OCT) is helpful in the diagnosis of foveal hypoplasia in children. METHODS Children with albinism and aniridia were examined with Stratus OCT 3 software 4.0.1 (Carl Zeiss Meditec, Dublin, California, USA). A qualitative examination of the macular area was performed with a 128 A-scans/second-single-scan. Macular thickness was measured quantitatively with an automatic fast macular map protocol. The average thickness/volume of the macula was presented as numerical values and as a false colour code in nine modified early treatment of diabetic retinopathy study (ETDRS) areas (A1-A9). A previously collected control group of children was used for comparison. RESULTS Macular thickness in 13 children with albinism and three children with aniridia was measured with OCT. Comparison with healthy children in the same population was performed. Patients with albinism and aniridia had significantly thicker central macula (A1) and foveola than children in the control group. CONCLUSION OCT was found to be useful in the diagnosis of foveal hypoplasia in children.
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Affiliation(s)
- Gerd Holmström
- Department of Ophthalmology, University Hospital, Uppsala, Sweden.
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Willemsen MA, Verbeek MM, Kamsteeg EJ, de Rijk-van Andel JF, Aeby A, Blau N, Burlina A, Donati MA, Geurtz B, Grattan-Smith PJ, Haeussler M, Hoffmann GF, Jung H, de Klerk JB, van der Knaap MS, Kok F, Leuzzi V, de Lonlay P, Megarbane A, Monaghan H, Renier WO, Rondot P, Ryan MM, Seeger J, Smeitink JA, Steenbergen-Spanjers GC, Wassmer E, Weschke B, Wijburg FA, Wilcken B, Zafeiriou DI, Wevers RA. Tyrosine hydroxylase deficiency: a treatable disorder of brain catecholamine biosynthesis. Brain 2010; 133:1810-22. [DOI: 10.1093/brain/awq087] [Citation(s) in RCA: 155] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Wei A, Wang Y, Long Y, Wang Y, Guo X, Zhou Z, Zhu W, Liu J, Bian X, Lian S, Li W. A Comprehensive Analysis Reveals Mutational Spectra and Common Alleles in Chinese Patients with Oculocutaneous Albinism. J Invest Dermatol 2010; 130:716-24. [DOI: 10.1038/jid.2009.339] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Liu J, Choy KW, Chan LWL, Leung TY, Tam POS, Chiang SWY, Lam DSC, Pang CP, Lai TYY. Tyrosinase gene (TYR) mutations in Chinese patients with oculocutaneous albinism type 1. Clin Exp Ophthalmol 2010; 38:37-42. [DOI: 10.1111/j.1442-9071.2009.02220.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Inheritance of a novel mutated allele of the OCA2 gene associated with high incidence of oculocutaneous albinism in a Polynesian community. J Hum Genet 2009; 55:103-11. [PMID: 20019752 DOI: 10.1038/jhg.2009.130] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Oculocutaneous albinism type 2 (OCA2) is a human autosomal-recessive hypopigmentation disorder associated with pathological mutations of the OCA2 gene. In this study, we investigated a form of OCA in a Polynesian population with an observed phenotype characterized by fair skin, some brown nevi present in the sun-exposed areas and green or blue eyes. Hair presented with a unique red coloration since birth, with tones ranging across individuals from Yellow-Red to Brown-Red, or Auburn. We genetically screened for mutations in the OCA2 and MC1R genes as their products have previously been shown to be associated with red hair/fair skin and OCA2. The SLC45A2 gene was also screened to identify any possible relation to skin color variation. We have identified a novel missense substitution in the OCA2 gene (Gly775Asp) responsible for OCA2 in individuals of Polynesian heritage from Tuvalu. The estimated incidence of this form of OCA2 in the primary study community is believed to occur at one of the highest recorded rates of albinism at approximately 1 per 669 individuals. In addition, we have analyzed four unrelated individuals with albinism who have Polynesian heritage from three other separate communities and found they carry the same OCA2 mutation. We also analyzed an out-group comprising three unrelated individuals with albinism of Melanesian ancestries from two separate communities, one Australian Aboriginal and three Australian Caucasians, and did not detect this mutation. We hypothesize that this mutation may be Polynesian specific and that it originated from a common founder.
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Murillo-Cuesta S, Contreras J, Zurita E, Cediel R, Cantero M, Varela-Nieto I, Montoliu L. Melanin precursors prevent premature age-related and noise-induced hearing loss in albino mice. Pigment Cell Melanoma Res 2009; 23:72-83. [PMID: 19843244 DOI: 10.1111/j.1755-148x.2009.00646.x] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Strial melanocytes are required for normal development and correct functioning of the cochlea. Hearing deficits have been reported in albino individuals from different species, although melanin appears to be not essential for normal auditory function. We have analyzed the auditory brainstem responses (ABR) of two transgenic mice: YRT2, carrying the entire mouse tyrosinase (Tyr) gene expression-domain and undistinguishable from wild-type pigmented animals; and TyrTH, non-pigmented but ectopically expressing tyrosine hydroxylase (Th) in melanocytes, which generate the precursor metabolite, L-DOPA, but not melanin. We show that young albino mice present a higher prevalence of profound sensorineural deafness and a poorer recovery of auditory thresholds after noise-exposure than transgenic mice. Hearing loss was associated with absence of cochlear melanin or its precursor metabolites and latencies of the central auditory pathway were unaltered. In summary, albino mice show impaired hearing responses during ageing and after noise damage when compared to YRT2 and TyrTH transgenic mice, which do not show the albino-associated ABR alterations. These results demonstrate that melanin precursors, such as L-DOPA, have a protective role in the mammalian cochlea in age-related and noise-induced hearing loss.
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Affiliation(s)
- Silvia Murillo-Cuesta
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas (CSIC), Universidad Autónoma de Madrid (UAM), Madrid, Spain
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Olivares C, Solano F. New insights into the active site structure and catalytic mechanism of tyrosinase and its related proteins. Pigment Cell Melanoma Res 2009; 22:750-60. [PMID: 19735457 DOI: 10.1111/j.1755-148x.2009.00636.x] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Tyrosinases are widely distributed in nature. They are copper-containing oxidases belonging to the type 3 copper protein family, together with catechol oxidases and haemocyanins. Tyrosinases are essential enzymes in melanin biosynthesis and therefore responsible for pigmentation of skin and hair in mammals, where two more enzymes, the tyrosinase-related proteins (Tyrps), participate in the pathway. The structure and catalytic mechanism of mammalian tyrosinases have been extensively studied but they are not completely understood because of the lack of information on the tertiary structure. The availability of crystallographic data of one plant catechol oxidase and one bacterial tyrosinase has improved the model of the three-dimensional structure of the active site of the enzyme. Furthermore, sequence comparison of tyrosinase and the Tyrps reveals that the three orthologue proteins share many key structural features, because of their common origin from an ancestral gene, although the specific residues responsible for their different catalytic capabilities have not been identified yet. This review summarizes our current knowledge of tyrosinase and Tyrps structure and function and describes the catalytic mechanism of tyrosinase and Dct/Tyrp2, which are better characterized.
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Affiliation(s)
- Concepcion Olivares
- Department of Biochemistry, Molecular Biology & Immunology, School of Medicine, University of Murcia, Espinardo, Spain
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Dessinioti C, Stratigos AJ, Rigopoulos D, Katsambas AD. A review of genetic disorders of hypopigmentation: lessons learned from the biology of melanocytes. Exp Dermatol 2009; 18:741-9. [PMID: 19555431 DOI: 10.1111/j.1600-0625.2009.00896.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Inherited diseases of pigmentation were among the first traits studied in humans because of their easy recognition. The discovery of genes that regulate melanocytic development and function and the identification of disease-causative mutations have greatly improved our understanding of the molecular basis of pigmentary genodermatoses and their underlying pathogenetic mechanisms. Pigmentation mutants can account for hypo-/amelanosis, with or without altered melanocyte number, resulting in different phenotypes, such as Waardenburg syndrome, piebaldism, Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, oculocutaneous albinism and Griscelli syndrome. In this review, we summarize the basic concepts of melanocyte biology and discuss how molecular defects in melanocyte development and function can result in the development of hypopigmentary hereditary skin diseases.
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Affiliation(s)
- Clio Dessinioti
- Department of Dermatology, A. Sygros Hospital, University of Athens, Athens, Greece
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Bakos RM, Argenziano G, Zalaudek I, Masiero NC, Zoratto G, Cartell A, Bakos L. Dermatoscopy of pigmented melanocytic nevi in patients with oculocutaneous albinism. J Am Acad Dermatol 2009; 60:487-9. [DOI: 10.1016/j.jaad.2008.09.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Revised: 08/20/2008] [Accepted: 09/03/2008] [Indexed: 11/28/2022]
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Mills MG, Patterson LB. Not just black and white: pigment pattern development and evolution in vertebrates. Semin Cell Dev Biol 2008; 20:72-81. [PMID: 19073271 DOI: 10.1016/j.semcdb.2008.11.012] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2008] [Accepted: 11/19/2008] [Indexed: 02/08/2023]
Abstract
Animals display diverse colors and patterns that vary within and between species. Similar phenotypes appear in both closely related and widely divergent taxa. Pigment patterns thus provide an opportunity to explore how development is altered to produce differences in form and whether similar phenotypes share a common genetic basis. Understanding the development and evolution of pigment patterns requires knowledge of the cellular interactions and signaling pathways that produce those patterns. These complex traits provide unparalleled opportunities for integrating studies from ecology and behavior to molecular biology and biophysics.
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Affiliation(s)
- Margaret G Mills
- Department of Biology, Box 351800, University of Washington, Seattle, WA 98195, USA.
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Chiang PW, Fulton AB, Spector E, Hisama FM. Synergistic interaction of theOCA2andOCA3genes in a family. Am J Med Genet A 2008; 146A:2427-30. [DOI: 10.1002/ajmg.a.32453] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Gangi Setty SR, Tenza D, Sviderskaya EV, Bennett DC, Raposo G, Marks MS. Cell-specific ATP7A transport sustains copper-dependent tyrosinase activity in melanosomes. Nature 2008; 454:1142-6. [PMID: 18650808 PMCID: PMC2812007 DOI: 10.1038/nature07163] [Citation(s) in RCA: 184] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Accepted: 06/10/2008] [Indexed: 11/08/2022]
Abstract
Copper is a cofactor for many cellular enzymes and transporters. It can be loaded onto secreted and endomembrane cuproproteins by translocation from the cytosol into membrane-bound organelles by ATP7A or ATP7B transporters, the genes for which are mutated in the copper imbalance syndromes Menkes disease and Wilson disease, respectively. Endomembrane cuproproteins are thought to incorporate copper stably on transit through the trans-Golgi network, in which ATP7A accumulates by dynamic cycling through early endocytic compartments. Here we show that the pigment-cell-specific cuproenzyme tyrosinase acquires copper only transiently and inefficiently within the trans-Golgi network of mouse melanocytes. To catalyse melanin synthesis, tyrosinase is subsequently reloaded with copper within specialized organelles called melanosomes. Copper is supplied to melanosomes by ATP7A, a cohort of which localizes to melanosomes in a biogenesis of lysosome-related organelles complex-1 (BLOC-1)-dependent manner. These results indicate that cell-type-specific localization of a metal transporter is required to sustain metallation of an endomembrane cuproenzyme, providing a mechanism for exquisite spatial control of metalloenzyme activity. Moreover, because BLOC-1 subunits are mutated in subtypes of the genetic disease Hermansky-Pudlak syndrome, these results also show that defects in copper transporter localization contribute to hypopigmentation, and hence perhaps other systemic defects, in Hermansky-Pudlak syndrome.
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Affiliation(s)
- Subba Rao Gangi Setty
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, 19104
| | - Danièle Tenza
- Institut Curie, Centre de Recherche, Paris F-75248, France
- Centre National de la Recherche Scientifique, UMR 144, Paris F-75248, France
| | - Elena V. Sviderskaya
- Centre for Molecular and Metabolic Signalling, Division of Basic Medical Sciences, St. George's, University of London, London SW17 0RE, UK
| | - Dorothy C. Bennett
- Centre for Molecular and Metabolic Signalling, Division of Basic Medical Sciences, St. George's, University of London, London SW17 0RE, UK
| | - Graça Raposo
- Institut Curie, Centre de Recherche, Paris F-75248, France
- Centre National de la Recherche Scientifique, UMR 144, Paris F-75248, France
| | - Michael S. Marks
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, 19104
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