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Guo Y, Wu W, Yang X. Coordinated microRNA/mRNA Expression Profiles Reveal Unique Skin Color Regulatory Mechanisms in Chinese Giant Salamander (Andrias davidianus). Animals (Basel) 2023; 13:ani13071181. [PMID: 37048437 PMCID: PMC10093658 DOI: 10.3390/ani13071181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/18/2023] [Accepted: 03/24/2023] [Indexed: 03/30/2023] Open
Abstract
The Chinese giant salamander (Andrias davidianus) has been increasingly popular in the aquaculture market in China in recent years. In the breeding process of Andrias davidianus, we found that some albino individuals were extremely rare and could not be inherited stably, which severely limits their commercialization in the aquaculture market. In this study, we performed transcriptome and small RNA (sRNA) sequencing analyses in the skin samples of wild-type (WT) and albino (AL) Andrias davidianus. In total, among 5517 differentially expressed genes (DEGs), 2911 DEGs were down-regulated in AL, including almost all the key genes involved in melanin formation. A total of 25 miRNAs were differentially expressed in AL compared to WT, of which 17 were up-regulated. Through the integrated analysis, no intersection was found between the target genes of the differentially expressed miRNAs and the key genes for melanin formation. Gene Ontology (GO) and KEGG pathway analyses on DEGs showed that these genes involved multiple processes relevant to melanin synthesis and the key signal pathway MAPK. Interestingly, the transcription factors SOX10 and PAX3 and the Wnt signaling pathway that play a key role in other species were not included, while the other two transcription factors in the SOX family, SOX21 and SOX7, were included. After analyzing the key genes for melanin formation, it was interesting to note an alternative splicing form of the MITF in WT and a critical mutation of the SLC24A5 gene in AL, which might be the main reason for the skin color change of Andrias davidianus. The results contributed to understanding the molecular mechanism of skin pigmentation in Andrias davidianus and accelerating the acquisition process of individuals with specific body colors by genetic means.
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Fernandes B, Cavaco-Paulo A, Matamá T. A Comprehensive Review of Mammalian Pigmentation: Paving the Way for Innovative Hair Colour-Changing Cosmetics. BIOLOGY 2023; 12:biology12020290. [PMID: 36829566 PMCID: PMC9953601 DOI: 10.3390/biology12020290] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/26/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023]
Abstract
The natural colour of hair shafts is formed at the bulb of hair follicles, and it is coupled to the hair growth cycle. Three critical processes must happen for efficient pigmentation: (1) melanosome biogenesis in neural crest-derived melanocytes, (2) the biochemical synthesis of melanins (melanogenesis) inside melanosomes, and (3) the transfer of melanin granules to surrounding pre-cortical keratinocytes for their incorporation into nascent hair fibres. All these steps are under complex genetic control. The array of natural hair colour shades are ascribed to polymorphisms in several pigmentary genes. A myriad of factors acting via autocrine, paracrine, and endocrine mechanisms also contributes for hair colour diversity. Given the enormous social and cosmetic importance attributed to hair colour, hair dyeing is today a common practice. Nonetheless, the adverse effects of the long-term usage of such cosmetic procedures demand the development of new methods for colour change. In this context, case reports of hair lightening, darkening and repigmentation as a side-effect of the therapeutic usage of many drugs substantiate the possibility to tune hair colour by interfering with the biology of follicular pigmentary units. By scrutinizing mammalian pigmentation, this review pinpoints key targetable processes for the development of innovative cosmetics that can safely change the hair colour from the inside out.
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Affiliation(s)
- Bruno Fernandes
- CEB—Centre of Biological Engineering, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal
| | - Artur Cavaco-Paulo
- CEB—Centre of Biological Engineering, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4710-057 Braga, Portugal
- Correspondence: (A.C.-P.); (T.M.); Tel.: +351-253-604-409 (A.C.-P.); +351-253-601-599 (T.M.)
| | - Teresa Matamá
- CEB—Centre of Biological Engineering, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal
- LABBELS—Associate Laboratory, 4710-057 Braga, Portugal
- Correspondence: (A.C.-P.); (T.M.); Tel.: +351-253-604-409 (A.C.-P.); +351-253-601-599 (T.M.)
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3
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The retinal pigmentation pathway in human albinism: Not so black and white. Prog Retin Eye Res 2022; 91:101091. [PMID: 35729001 DOI: 10.1016/j.preteyeres.2022.101091] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 05/24/2022] [Accepted: 05/26/2022] [Indexed: 12/16/2022]
Abstract
Albinism is a pigment disorder affecting eye, skin and/or hair. Patients usually have decreased melanin in affected tissues and suffer from severe visual abnormalities, including foveal hypoplasia and chiasmal misrouting. Combining our data with those of the literature, we propose a single functional genetic retinal signalling pathway that includes all 22 currently known human albinism disease genes. We hypothesise that defects affecting the genesis or function of different intra-cellular organelles, including melanosomes, cause syndromic forms of albinism (Hermansky-Pudlak (HPS) and Chediak-Higashi syndrome (CHS)). We put forward that specific melanosome impairments cause different forms of oculocutaneous albinism (OCA1-8). Further, we incorporate GPR143 that has been implicated in ocular albinism (OA1), characterised by a phenotype limited to the eye. Finally, we include the SLC38A8-associated disorder FHONDA that causes an even more restricted "albinism-related" ocular phenotype with foveal hypoplasia and chiasmal misrouting but without pigmentation defects. We propose the following retinal pigmentation pathway, with increasingly specific genetic and cellular defects causing an increasingly specific ocular phenotype: (HPS1-11/CHS: syndromic forms of albinism)-(OCA1-8: OCA)-(GPR143: OA1)-(SLC38A8: FHONDA). Beyond disease genes involvement, we also evaluate a range of (candidate) regulatory and signalling mechanisms affecting the activity of the pathway in retinal development, retinal pigmentation and albinism. We further suggest that the proposed pigmentation pathway is also involved in other retinal disorders, such as age-related macular degeneration. The hypotheses put forward in this report provide a framework for further systematic studies in albinism and melanin pigmentation disorders.
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Brown AR, Comai K, Mannino D, McCullough H, Donekal Y, Meyers HC, Graves CW, Seidel HS. A community-science approach identifies genetic variants associated with three color morphs in ball pythons (Python regius). PLoS One 2022; 17:e0276376. [PMID: 36260636 PMCID: PMC9581371 DOI: 10.1371/journal.pone.0276376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Accepted: 10/05/2022] [Indexed: 11/13/2022] Open
Abstract
Color morphs in ball pythons (Python regius) provide a unique and largely untapped resource for understanding the genetics of coloration in reptiles. Here we use a community-science approach to investigate the genetics of three color morphs affecting production of the pigment melanin. These morphs-Albino, Lavender Albino, and Ultramel-show a loss of melanin in the skin and eyes, ranging from severe (Albino) to moderate (Lavender Albino) to mild (Ultramel). To identify genetic variants causing each morph, we recruited shed skins of pet ball pythons via social media, extracted DNA from the skins, and searched for putative loss-of-function variants in homologs of genes controlling melanin production in other vertebrates. We report that the Albino morph is associated with missense and non-coding variants in the gene TYR. The Lavender Albino morph is associated with a deletion in the gene OCA2. The Ultramel morph is associated with a missense variant and a putative deletion in the gene TYRP1. Our study is one of the first to identify genetic variants associated with color morphs in ball pythons and shows that pet samples recruited from the community can provide a resource for genetic studies in this species.
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Affiliation(s)
- Autumn R. Brown
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, United States of America
| | - Kaylee Comai
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, United States of America
| | - Dominic Mannino
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, United States of America
| | - Haily McCullough
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, United States of America
| | - Yamini Donekal
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, United States of America
| | - Hunter C. Meyers
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, United States of America
| | - Chiron W. Graves
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, United States of America
- * E-mail: (CWG); (HSS)
| | - Hannah S. Seidel
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, United States of America
- * E-mail: (CWG); (HSS)
| | - The BIO306W Consortium
- Department of Biology, Eastern Michigan University, Ypsilanti, MI, United States of America
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5
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Ma L, Zhu J, Wang J, Huang Y, Zhang J, Wang C, Zhou Y, Peng D. Genetic Analysis of 28 Chinese Families With Tyrosinase-Positive Oculocutaneous Albinism. Front Genet 2021; 12:715437. [PMID: 34707637 PMCID: PMC8544823 DOI: 10.3389/fgene.2021.715437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 07/30/2021] [Indexed: 11/28/2022] Open
Abstract
Background Tyrosinase-positive oculocutaneous albinism (OCA, type II, OCA2) is an autosomal recessive genetic disease in which the biosynthesis of melanin decreases in the skin, hair, and eyes. OCA2 disease is caused by mutations in OCA2 gene. The gene product plays a role in regulating the pH of melanosomes. Up to now, hundreds of OCA2 mutations have been reported and novel variants are still being discovered. Methods In this study, we reviewed the records of OCA2 patients who had conducted albinism genetic testing, and then analyzed the clinical and genetic information of 28 OCA2 patients who had been genetically diagnosed by using Sanger sequencing and next-generation sequencing. Results In this study, we reported 31 variants screened from 28 Chinese OCA2 families, and characterized the detailed molecular and clinical presentations. There were 12 novel variants among all detected variants, including 3 missense variants (p.G393V, p.T482A, and p.R720P), 4 frameshift variants (p.R53Gfs∗49, p.N279Kfs∗17, p.I469Lfs∗4, p.I655Nfs∗12), 2 splicing variants (c.1637-2A > G, c.1951 + 1G > C), 2 stopgain variants (p.L278X, p.W652X) and 1 insertion variants (p.P315LinsT). One potential cluster of missense variants was implicated indicating the important roles of the underlying domains in OCA2 pathogenesis. Conclusion Our results were beneficial for diagnosis and precision clinical management for OCA2-related disorder, and this study expanded the mutation spectrum of oculocutaneous albinism.
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Affiliation(s)
- Linya Ma
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Jianjian Zhu
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Jing Wang
- Changsha Kingmed Center for Clinical Laboratory, Changsha, China
| | - Yazhou Huang
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Jibo Zhang
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Chao Wang
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Yuan Zhou
- Department of Medical Genetics, Changde First People's Hospital, Changde, China
| | - Dan Peng
- Department of Medical Genetics, Changde First People's Hospital, Changde, China.,Affiliated Hospital of Changde City, University of South China, Hengyang, China
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Scales JL, Koroma DC, Oancea E. Single organelle measurements of melanosome pH using the novel ratiometric indicator RpHiMEL. Methods Enzymol 2021; 654:315-344. [PMID: 34120720 DOI: 10.1016/bs.mie.2021.03.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Melanocytes are specialized cells that produce melanin pigments responsible for skin, hair, and eye pigmentation. The synthesis and storage of melanin occurs in unique lysosome-related organelles called melanosomes, which regulate melanin production via complex regulatory mechanisms. Maintenance of the melanosome luminal ionic environment and pH is crucial for proper function of the main melanogenic enzymes. Defects in genes encoding pH-regulating melanosomal proteins result in oculocutaneous albinism, which is characterized by hypopigmentation, impaired vision, and increased susceptibility to skin and eye cancers. We recently uncovered several ion channels and transporters that modulate melanin synthesis by acidifying or neutralizing the luminal pH of melanosomes. However, our understanding of how melanosomes and other related organelles maintain their luminal pH is far from complete. The study of melanosome pH regulation requires robust imaging and quantification tools. Despite recent advances in the development of such methods, many limitations remain, particularly for quantitative analysis of individual organelle pH. In this chapter, we will provide an overview of the available methods used for melanosome pH determination, including their advantages, limitations, and challenges. To address the critical, unmet need for reliable melanosome pH quantification tools, we engineered a novel genetically encoded, ratiometric pH sensor for melanosomes that we named RpHiMEL. Here, we describe the design and optimization of RpHiMEL, and provide a pH quantification method for individual melanosomes in live cells. We demonstrate that RpHiMEL is a highly versatile tool with the potential to advance our understanding of pH regulation in melanosomes and related organelles.
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Affiliation(s)
- Jessica L Scales
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States
| | - Donald C Koroma
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States
| | - Elena Oancea
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States.
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Feng Y, McQuillan MA, Tishkoff SA. Evolutionary genetics of skin pigmentation in African populations. Hum Mol Genet 2021; 30:R88-R97. [PMID: 33438000 PMCID: PMC8117430 DOI: 10.1093/hmg/ddab007] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/07/2021] [Accepted: 01/07/2021] [Indexed: 12/14/2022] Open
Abstract
Skin color is a highly heritable human trait, and global variation in skin pigmentation has been shaped by natural selection, migration and admixture. Ethnically diverse African populations harbor extremely high levels of genetic and phenotypic diversity, and skin pigmentation varies widely across Africa. Recent genome-wide genetic studies of skin pigmentation in African populations have advanced our understanding of pigmentation biology and human evolutionary history. For example, novel roles in skin pigmentation for loci near MFSD12 and DDB1 have recently been identified in African populations. However, due to an underrepresentation of Africans in human genetic studies, there is still much to learn about the evolutionary genetics of skin pigmentation. Here, we summarize recent progress in skin pigmentation genetics in Africans and discuss the importance of including more ethnically diverse African populations in future genetic studies. In addition, we discuss methods for functional validation of adaptive variants related to skin pigmentation.
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Affiliation(s)
- Yuanqing Feng
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Michael A McQuillan
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sarah A Tishkoff
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
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8
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Ullate-Agote A, Burgelin I, Debry A, Langrez C, Montange F, Peraldi R, Daraspe J, Kaessmann H, Milinkovitch MC, Tzika AC. Genome mapping of a LYST mutation in corn snakes indicates that vertebrate chromatophore vesicles are lysosome-related organelles. Proc Natl Acad Sci U S A 2020; 117:26307-26317. [PMID: 33020272 PMCID: PMC7584913 DOI: 10.1073/pnas.2003724117] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Reptiles exhibit a spectacular diversity of skin colors and patterns brought about by the interactions among three chromatophore types: black melanophores with melanin-packed melanosomes, red and yellow xanthophores with pteridine- and/or carotenoid-containing vesicles, and iridophores filled with light-reflecting platelets generating structural colors. Whereas the melanosome, the only color-producing endosome in mammals and birds, has been documented as a lysosome-related organelle, the maturation paths of xanthosomes and iridosomes are unknown. Here, we first use 10x Genomics linked-reads and optical mapping to assemble and annotate a nearly chromosome-quality genome of the corn snake Pantherophis guttatus The assembly is 1.71 Gb long, with an N50 of 16.8 Mb and L50 of 24. Second, we perform mapping-by-sequencing analyses and identify a 3.9-Mb genomic interval where the lavender variant resides. The lavender color morph in corn snakes is characterized by gray, rather than red, blotches on a pink, instead of orange, background. Third, our sequencing analyses reveal a single nucleotide polymorphism introducing a premature stop codon in the lysosomal trafficking regulator gene (LYST) that shortens the corresponding protein by 603 amino acids and removes evolutionary-conserved domains. Fourth, we use light and transmission electron microscopy comparative analyses of wild type versus lavender corn snakes and show that the color-producing endosomes of all chromatophores are substantially affected in the LYST mutant. Our work provides evidence characterizing xanthosomes in xanthophores and iridosomes in iridophores as lysosome-related organelles.
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Affiliation(s)
- Asier Ullate-Agote
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, CH-1211 Geneva, Switzerland
- SIB Swiss Institute of Bioinformatics, Switzerland
- Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland
| | - Ingrid Burgelin
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, CH-1211 Geneva, Switzerland
| | - Adrien Debry
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, CH-1211 Geneva, Switzerland
| | - Carine Langrez
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, CH-1211 Geneva, Switzerland
| | - Florent Montange
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, CH-1211 Geneva, Switzerland
| | - Rodrigue Peraldi
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, CH-1211 Geneva, Switzerland
| | - Jean Daraspe
- Faculté de Biologie et de Médecine, Electron Microscopy Facility, University of Lausanne, CH-1015 Lausanne, Switzerland
| | - Henrik Kaessmann
- DKFZ-ZMBH Alliance, Center for Molecular Biology of Heidelberg University (ZMBH), D-69120 Heidelberg, Germany
| | - Michel C Milinkovitch
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, CH-1211 Geneva, Switzerland
- SIB Swiss Institute of Bioinformatics, Switzerland
- Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland
| | - Athanasia C Tzika
- Laboratory of Artificial & Natural Evolution (LANE), Department of Genetics & Evolution, University of Geneva, CH-1211 Geneva, Switzerland;
- SIB Swiss Institute of Bioinformatics, Switzerland
- Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, Geneva, Switzerland
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9
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Okamura K, Suzuki T. Current landscape of Oculocutaneous Albinism in Japan. Pigment Cell Melanoma Res 2020; 34:190-203. [PMID: 32969595 DOI: 10.1111/pcmr.12927] [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: 08/24/2020] [Revised: 09/05/2020] [Accepted: 09/10/2020] [Indexed: 12/16/2022]
Abstract
Oculocutaneous albinism (OCA), which is roughly divided into non-syndromic and syndromic OCA, is a group of autosomal recessive disorders caused by mutations in genes associated with pigmentation. Patients with OCA have hypopigmentation and ocular manifestations such as photophobia, amblyopia, and nystagmus. Hermansky-Pudlak syndrome (HPS), the most common syndromic OCA, is characterized by the additional features of a bleeding tendency and other critical systemic comorbidities such as pulmonary fibrosis and immunodeficiency. NGS-based gene analyses have identified several new causative genes for OCA and have detected rare subtypes of OCA with high accuracy including Japanese patients. In our survey of 190 Japanese OCA patients/families, OCA4 is the most common subtype (25.3%) followed by OCA1 (20.0%), HPS1 (14.7%), and OCA2 (8.4%). Similar to the A481T variant in OCA2, which is associated with a mild form of OCA2 and skin color variation, the c.-492_489delAATG variant located in the promoter region of SLC45A2 has been uniquely identified in Japanese patients with a mild form of OCA4. Further, rare OCA subtypes, including OCA3, HPS2, HPS3, HPS4, HPS5, HPS6, and HPS9, have also been identified in Japanese patients. The clinical characteristics and underlying molecular mechanisms of each subtype of OCA are concisely summarized in this review.
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Affiliation(s)
- Ken Okamura
- Department of Dermatology, Faculty of Medicine, Yamagata University, Yamagata, Japan
| | - Tamio Suzuki
- Department of Dermatology, Faculty of Medicine, Yamagata University, Yamagata, Japan
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10
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Dolinska MB, Wingfield PT, Young KL, Sergeev YV. The TYRP1-mediated protection of human tyrosinase activity does not involve stable interactions of tyrosinase domains. Pigment Cell Melanoma Res 2019; 32:753-765. [PMID: 31077632 DOI: 10.1111/pcmr.12791] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 04/15/2019] [Accepted: 05/04/2019] [Indexed: 12/20/2022]
Abstract
Tyrosinases are melanocyte-specific enzymes involved in melanin biosynthesis. Mutations in their genes cause oculocutaneous albinism associated with reduced or altered pigmentation of skin, hair, and eyes. Here, the recombinant human intra-melanosomal domains of tyrosinase, TYRtr (19-469), and tyrosinase-related protein 1, TYRP1tr (25-472), were studied in vitro to define their functional relationship. Proteins were expressed or coexpressed in whole Trichoplusia ni larvae and purified. Their associations were studied using gel filtration and sedimentation equilibrium methods. Protection of TYRtr was studied by measuring the kinetics of tyrosinase diphenol oxidase activity in the presence (1:1 and 1:20 molar ratios) or the absence of TYRP1tr for 10 hr under conditions mimicking melanosomal and ER pH values. Our data indicate that TYRtr incubation with excess TYRP1tr protects TYR, increasing its stability over time. However, this mechanism does not appear to involve the formation of stable hetero-oligomeric complexes to maintain the protective function.
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Affiliation(s)
- Monika B Dolinska
- National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Paul T Wingfield
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland
| | - Kenneth L Young
- National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Yuri V Sergeev
- National Eye Institute, National Institutes of Health, Bethesda, Maryland
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Singh BK, Kim EK. P-Protein: A Novel Target for Skin-whitening Agent. BIOTECHNOL BIOPROC E 2019. [DOI: 10.1007/s12257-018-0241-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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12
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Pedersen JN, Jiang Z, Christiansen G, Lee JC, Pedersen JS, Otzen DE. Lysophospholipids induce fibrillation of the repeat domain of Pmel17 through intermediate core-shell structures. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1867:519-528. [PMID: 30471451 DOI: 10.1016/j.bbapap.2018.11.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 11/02/2018] [Accepted: 11/17/2018] [Indexed: 11/26/2022]
Abstract
Lipids often play an important role in the initial steps of fibrillation. The melanosomal protein Pmel17 forms amyloid in vivo and contains a highly amyloidogenic Repeat domain (RPT), important for melanin biosynthesis. RPT fibrillation is influenced by two lysolipids, the anionic lysophosphatidylglycerol (LPG) and zwitterionic lysophosphatidylcholine (LPC), both present in vivo at elevated concentrations in melanosomes, organelles in which Pmel17 aggregate. Here we investigate the interaction of RPT with both LPG and LPC using small-angle X-ray scattering (SAXS), isothermal titration calorimetry (ITC), electron microscopy, fluorescence and circular dichroism (CD) spectroscopy. Under non-shaking conditions, both lipids promote fibrillation but this is driven by different interactions with RPT. Each RPT binds >40 LPG molecules but only weak interactions are seen with LPC. Above LPG's criticial micelle concentration (cmc), LPG and RPT form connected micelles where RPT binds to the surface as beads on a string with core-shell structures. Binding to LPG only induces α-helical structure well above the cmc, while LPC has no measurable effect on the protein structure. While low (but still super-cmc) concentrations of LPG strongly promote aggregation, at higher LPG concentrations (10 mM), only ~ one RPT binds per micelle, inhibiting amyloid formation. ITC and SAXS reveal some interactions between the zwitterionic lipid LPC and RPT below the cmc but little above the cmc. Nevertheless, LPC only promotes aggregation above the cmc and this process is not inhibited by high LPC concentrations, suggesting that monomers and micelles cooperate to influence amyloid formation.
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Affiliation(s)
- Jannik Nedergaard Pedersen
- Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark
| | - Zhiping Jiang
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8013, USA
| | - Gunna Christiansen
- Department of Biomedicine, Aarhus University, Wilhelm Meyers Allé 4, DK-8000 Aarhus, Denmark
| | - Jennifer C Lee
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8013, USA
| | - Jan Skov Pedersen
- Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark.
| | - Daniel E Otzen
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus, Denmark.
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Zhou D, Ota K, Nardin C, Feldman M, Widman A, Wind O, Simon A, Reilly M, Levin LR, Buck J, Wakamatsu K, Ito S, Zippin JH. Mammalian pigmentation is regulated by a distinct cAMP-dependent mechanism that controls melanosome pH. Sci Signal 2018; 11:11/555/eaau7987. [PMID: 30401788 DOI: 10.1126/scisignal.aau7987] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The production of melanin increases skin pigmentation and reduces the risk of skin cancer. Melanin production depends on the pH of melanosomes, which are more acidic in lighter-skinned than in darker-skinned people. We showed that inhibition of soluble adenylyl cyclase (sAC) controlled pigmentation by increasing the pH of melanosomes both in cells and in vivo. Distinct from the canonical melanocortin 1 receptor (MC1R)-dependent cAMP pathway that controls pigmentation by altering gene expression, we found that inhibition of sAC increased pigmentation by increasing the activity of tyrosinase, the rate-limiting enzyme in melanin synthesis, which is more active at basic pH. We demonstrated that the effect of sAC activity on pH and melanin production in human melanocytes depended on the skin color of the donor. Last, we identified sAC inhibitors as a new class of drugs that increase melanosome pH and pigmentation in vivo, suggesting that pharmacologic inhibition of this pathway may affect skin cancer risk or pigmentation conditions.
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Affiliation(s)
- Dalee Zhou
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Koji Ota
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Charlee Nardin
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA.,Service de Dermatologie, Centre Hospitalier Universitaire, Besançon 25030, France
| | - Michelle Feldman
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Adam Widman
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Olivia Wind
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Amanda Simon
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Michael Reilly
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA
| | - Lonny R Levin
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Jochen Buck
- Department of Pharmacology, Weill Cornell Medical College, New York, NY 10065, USA
| | - Kazumasa Wakamatsu
- Department of Chemistry, Fujita Health University School of Health Sciences, Toyoake 470-1192, Japan
| | - Shosuke Ito
- Department of Chemistry, Fujita Health University School of Health Sciences, Toyoake 470-1192, Japan
| | - Jonathan H Zippin
- Department of Dermatology, Weill Cornell Medical College, New York, NY 10021, USA.
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14
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Comprehensive Review of the Genetics of Albinism. JOURNAL OF VISUAL IMPAIRMENT & BLINDNESS 2018. [DOI: 10.1177/0145482x1811200604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Introduction It is important to understand albinism, since it is a disorder associated with visual impairment, predisposition to malignant melanomas, and social stigma. The main objective of this article is to review the genetics and biologic mechanisms of the non-syndromic albinism subtypes and to describe associated clinical manifestations. We also discuss research on its treatments. Methods A review of the published literature on albinism subtypes was performed, spanning basic laboratory research, published case reports, and experiences of people with albinism. Results Clear progress has been made in comprehending the causes of albinism; research has shed light on the complexity of the disorder and has led to the molecular classification of subtypes. Discussion Despite the increase in knowledge with regards to albinism, gaps still exist. It is important to continue the pursuit of unraveling the mechanism of the disorder and to monitor the frequency of the subtypes worldwide in order to aid in the development of treatments. Furthermore, disseminating knowledge of albinism is crucial for future progress. Implications for practitioners Albinism is a disorder characterized by hypopigmentation of the hair, skin, and eyes, with accompanying ocular abnormalities that remain relatively stable throughout life. The disorder is defined by a spectrum of pigmentation where albinism is more evident among individuals of dark complexion than their lighter-pigmented peers. Patients with albinism require protection against sun exposure and special resources to address visual impairments. When albinism patients are diagnosed and properly accommodated, they generally report a positive quality of life.
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15
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Arshad MW, Harlalka GV, Lin S, D'Atri I, Mehmood S, Shakil M, Hassan MJ, Chioza BA, Self JE, Ennis S, O'Gorman L, Norman C, Aman T, Ali SS, Kaul H, Baple EL, Crosby AH, Ullah MI, Shabbir MI. Mutations in TYR and OCA2 associated with oculocutaneous albinism in Pakistani families. Meta Gene 2018. [DOI: 10.1016/j.mgene.2018.03.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
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16
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Adachi E, Sakai K, Nishiuchi T, Imamura R, Sato H, Matsumoto K. Different growth and metastatic phenotypes associated with a cell-intrinsic change of Met in metastatic melanoma. Oncotarget 2018; 7:70779-70793. [PMID: 27683122 PMCID: PMC5342589 DOI: 10.18632/oncotarget.12221] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 09/13/2016] [Indexed: 12/19/2022] Open
Abstract
A dynamic phenotypic change contributes to the metastatic progression and drug resistance in malignant melanoma. Nevertheless, mechanisms for a phenotypic change have remained to be addressed. Here, we show that Met receptor expression changes in a cell-autonomous manner and can distinguish phenotypical differences in growth, as well as in metastatic and drug-resistant characteristics. In metastatic melanoma, the cells are composed of Met-low and Met-high populations. Met-low populations have stem-like gene expression profiles, are resistant to chemotherapeutic agents, and have shown abundant angiogenesis and rapid tumor growth in subcutaneous inoculation. Met-high populations have a differentiated phenotype, are relatively resistant to B-RAF inhibitor, and are highly metastatic to the lungs. Met plays a definitive role in lung metastasis because the lung metastasis of Met-high cells requires Met, and treatment of mice with the Met-containing exosomes from Met-high cells facilitates lung metastasis by Met-low cells. Clonal cell fate analysis showed the hierarchical phenotypical changes from Met-low to Met-high populations. Met-low cells either showed self-renewal or changed into Met-high cells, whereas Met-high cells remained Met-high. Clonal transition from Met-low to Met-high cells accompanied changes in the gene expression profile, in tumor growth, and in metastasis that were similar to those in Met-high cells. These findings indicate that malignant melanoma has the ability to undergo phenotypic change by a cell-intrinsic/autonomous mechanism that can be characterized by Met expression.
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Affiliation(s)
- Eri Adachi
- Division of Tumor Dynamics and Regulation, Cancer Research Institute, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan
| | - Katsuya Sakai
- Division of Tumor Dynamics and Regulation, Cancer Research Institute, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan
| | - Takumi Nishiuchi
- Division of Functional Genomics, Advanced Science Research Center, Kanazawa University, Kakuma, Kanazawa 920-0934, Japan
| | - Ryu Imamura
- Division of Tumor Dynamics and Regulation, Cancer Research Institute, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan
| | - Hiroki Sato
- Division of Tumor Dynamics and Regulation, Cancer Research Institute, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan
| | - Kunio Matsumoto
- Division of Tumor Dynamics and Regulation, Cancer Research Institute, Kanazawa University, Kakuma, Kanazawa 920-1192, Japan
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17
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Rimpelä AK, Reinisalo M, Hellinen L, Grazhdankin E, Kidron H, Urtti A, del Amo EM. Implications of melanin binding in ocular drug delivery. Adv Drug Deliv Rev 2018; 126:23-43. [PMID: 29247767 DOI: 10.1016/j.addr.2017.12.008] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 10/04/2017] [Accepted: 12/11/2017] [Indexed: 12/20/2022]
Abstract
Pigmented ocular tissues contain melanin within the intracellular melanosomes. Drugs bind to melanin at varying extent that ranges from no binding to extensive binding. Binding may lead to drug accumulation to the pigmented tissues and prolonged drug retention in the melanin containing cells. Therefore, melanin binding is an important feature that affects ocular drug delivery and biodistribution, but this topic has not been reviewed since 1998. In this review, we present current knowledge on ocular melanin, melanosomes and binding of drugs to pigmented cells and tissues. In vitro, in vivo and in silico methods in the field were critically evaluated, because the literature in this field can be confusing if the reader does not properly understand the methodological aspects. Literature analysis includes a comprehensive table of literature data on melanin binding of drugs. Furthermore, we aimed to give some insights beyond the current literature by making a chemical structure based classification model for melanin binding of drugs and kinetic simulations that revealed significant interplay between melanin binding and drug permeability across the melanosomal and plasma membranes. Overall, more mechanistic and systematic research is needed before the impact of melanin binding on ocular drug delivery can be properly understood and predicted.
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18
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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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19
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Andrade ES, Fracasso NC, Strazza Júnior PS, Simões AL, Mendes-Junior CT. Associations of OCA2 - HERC2 SNPs and haplotypes with human pigmentation characteristics in the Brazilian population. Leg Med (Tokyo) 2017; 24:78-83. [DOI: 10.1016/j.legalmed.2016.12.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 11/24/2016] [Accepted: 12/14/2016] [Indexed: 10/20/2022]
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20
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Making the invisible visible. Semin Cell Dev Biol 2016; 52:58-65. [PMID: 26877141 DOI: 10.1016/j.semcdb.2016.02.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Revised: 02/08/2016] [Accepted: 02/08/2016] [Indexed: 12/13/2022]
Abstract
In this review, I will discuss how careful scrutiny of genetic skin disorders could help us to understand human biology. Like other organs, the skin and its appendages, such as hairs and teeth, experience fundamental biological processes ranging from lipid metabolism to vesicular transport and cellular migration. However, in contrast to other organ systems, they are accessible and can be studied with relative ease. By visually revealing the functional consequences of single gene defects, genetic skin diseases offer a unique opportunity to study human biology. Here, I will illustrate this concept by discussing how human genetic disorders of skin pigmentation reflect the mechanisms underlying this complex and vital process.
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21
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Jung H, Chung H, Chang SE, Kang DH, Oh ES. FK506 regulates pigmentation by maturing the melanosome and facilitating their transfer to keratinocytes. Pigment Cell Melanoma Res 2016; 29:199-209. [DOI: 10.1111/pcmr.12443] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 10/22/2015] [Indexed: 11/30/2022]
Affiliation(s)
- Hyejung Jung
- Department of Life Sciences; The Research Center for Cellular Homeostasis; Ewha Womans University; Seoul Korea
| | - Heesung Chung
- Department of Life Sciences; The Research Center for Cellular Homeostasis; Ewha Womans University; Seoul Korea
| | - Sung Eun Chang
- Department of Dermatology; Asan Medical Center; University of Ulsan College of Medicine; Seoul Korea
| | - Duk-Hee Kang
- Division of Nephrology; Department of Internal Medicine; Ewha Medical Research Center; Ewha Womans University School of Medicine; Seoul Korea
| | - Eok-Soo Oh
- Department of Life Sciences; The Research Center for Cellular Homeostasis; Ewha Womans University; Seoul Korea
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22
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Yang Z, Zhong H, Chen J, Zhang X, Zhang H, Luo X, Xu S, Chen H, Lu D, Han Y, Li J, Fu L, Qi X, Peng Y, Xiang K, Lin Q, Guo Y, Li M, Cao X, Zhang Y, Liao S, Peng Y, Zhang L, Guo X, Dong S, Liang F, Wang J, Willden A, Seang Aun H, Serey B, Sovannary T, Bunnath L, Samnom H, Mardon G, Li Q, Meng A, Shi H, Su B. A Genetic Mechanism for Convergent Skin Lightening during Recent Human Evolution. Mol Biol Evol 2016; 33:1177-87. [PMID: 26744415 PMCID: PMC4839214 DOI: 10.1093/molbev/msw003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Skin lightening among Eurasians is thought to have been a convergence occurring independently in Europe and East Asia as an adaptation to high latitude environments. Among Europeans, several genes responsible for such lightening have been found, but the information available for East Asians is much more limited. Here, a genome-wide comparison between dark-skinned Africans and Austro-Asiatic speaking aborigines and light-skinned northern Han Chinese identified the pigmentation gene OCA2, showing unusually deep allelic divergence between these groups. An amino acid substitution (His615Arg) of OCA2 prevalent in most East Asian populations—but absent in Africans and Europeans—was significantly associated with skin lightening among northern Han Chinese. Further transgenic and targeted gene modification analyses of zebrafish and mouse both exhibited the phenotypic effect of the OCA2 variant manifesting decreased melanin production. These results indicate that OCA2 plays an important role in the convergent skin lightening of East Asians during recent human evolution.
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Affiliation(s)
- Zhaohui Yang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing, China Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Hua Zhong
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX
| | - Jing Chen
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Xiaoming Zhang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Hui Zhang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Xin Luo
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Shuhua Xu
- Max Planck Independent Research Group on Population Genomics, Chinese Academy of Sciences and Max Planck Society (CAS-MPG) Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Hua Chen
- Center for Computational Genomics, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
| | - Dongsheng Lu
- Max Planck Independent Research Group on Population Genomics, Chinese Academy of Sciences and Max Planck Society (CAS-MPG) Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Yinglun Han
- College of Life Science, Liaoning Normal University, Dalian, China
| | - Jinkun Li
- Department of Urology, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Lijie Fu
- Department of Urology, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Xuebin Qi
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yi Peng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Kun Xiang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Qiang Lin
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China Kunming College of Life Science, University of Chinese Academy of Sciences, Beijing, China
| | - Yan Guo
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Ming Li
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Xiangyu Cao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yanfeng Zhang
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Shiyu Liao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Yingmei Peng
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Lin Zhang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Xiaosen Guo
- BGI-Shenzhen, Shenzhen, China Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Jun Wang
- BGI-Shenzhen, Shenzhen, China Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Andrew Willden
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Hong Seang Aun
- Geography and Land Management, Royal University of Phnom Penh, Phnom Penh, Kingdom of Cambodia
| | - Bun Serey
- Geography and Land Management, Royal University of Phnom Penh, Phnom Penh, Kingdom of Cambodia
| | - Tuot Sovannary
- Geography and Land Management, Royal University of Phnom Penh, Phnom Penh, Kingdom of Cambodia
| | - Long Bunnath
- Geography and Land Management, Royal University of Phnom Penh, Phnom Penh, Kingdom of Cambodia
| | - Ham Samnom
- Capacity Development Facilitator for Handicap International Federation and Freelance Researcher, Battambang, Kingdom of Cambodia
| | - Graeme Mardon
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX
| | - Qingwei Li
- College of Life Science, Liaoning Normal University, Dalian, China
| | - Anming Meng
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Hong Shi
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China Institute of Primate Translational Medicine, Kunming University of Science and Technology, Kunming, Yunnan, China
| | - Bing Su
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
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Amelanism in the corn snake is associated with the insertion of an LTR-retrotransposon in the OCA2 gene. Sci Rep 2015; 5:17118. [PMID: 26597053 PMCID: PMC4657000 DOI: 10.1038/srep17118] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/26/2015] [Indexed: 12/21/2022] Open
Abstract
The corn snake (Pantherophis guttatus) is a new model species particularly appropriate for investigating the processes generating colours in reptiles because numerous colour and pattern mutants have been isolated in the last five decades. Using our captive-bred colony of corn snakes, transcriptomic and genomic next-generation sequencing, exome assembly, and genotyping of SNPs in multiple families, we delimit the genomic interval bearing the causal mutation of amelanism, the oldest colour variant observed in that species. Proceeding with sequencing the candidate gene OCA2 in the uncovered genomic interval, we identify that the insertion of an LTR-retrotransposon in its 11th intron results in a considerable truncation of the p protein and likely constitutes the causal mutation of amelanism in corn snakes. As amelanistic snakes exhibit white, instead of black, borders around an otherwise normal pattern of dorsal orange saddles and lateral blotches, our results indicate that melanocytes lacking melanin are able to participate to the normal patterning of other colours in the skin. In combination with research in the zebrafish, this work opens the perspective of using corn snake colour and pattern variants to investigate the generative processes of skin colour patterning shared among major vertebrate lineages.
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l-tyrosine induces melanocyte differentiation in novel pink-eyed dilution castaneus mouse mutant showing age-related pigmentation. J Dermatol Sci 2015; 80:203-11. [PMID: 26475433 DOI: 10.1016/j.jdermsci.2015.10.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Revised: 08/05/2015] [Accepted: 10/01/2015] [Indexed: 11/23/2022]
Abstract
BACKGROUND The mouse pink-eyed dilution (oculocutaneous albinism II; p/Oca2(p)) locus is known to control tyrosinase activity, melanin content, and melanosome development in melanocytes. Pink-eyed dilution castaneus (p(cas)/Oca2(p-cas)) is a novel mutant allele on mouse chromosome 7 that arose spontaneously in Indonesian wild mice, Mus musculus castaneus. Mice homozygous for Oca2(p-cas) usually exhibit pink eyes and beige-colored coat on nonagouti C57BL/6 (B6) background. Recently, a novel spontaneous mutation occurred in the progeny between this mutant and B6 mice. The eyes of this novel mutant progressively become black from pink and the coat becomes dark gray from beige with aging. OBJECTIVE The aim of this study is to clarify whatever differences exist in melanocyte proliferation and differentiation between the ordinary (pink-eyed) and novel (black-eyed) mutant using serum-free primary culture system. METHODS The characteristics of melanocyte proliferation and differentiation were investigated by serum-free primary culture system using melanocyte-proliferation medium (MDMD). RESULTS The proliferation of melanoblasts in MDMD did not differ between the two mice. However, when the epidermal cell suspensions were cultured with MDMD supplemented with l-tyrosine (Tyr), the differentiation of black-eyed melanocytes was greatly induced in a concentration-dependent manner compared with pink-eyed melanocytes. Immunocytochemistry demonstrated that the expression of tyrosinase and tyrosinase-related protein-1 (Tyrp1) was greatly induced or stimulated both in pink-eyed and black-eyed melanocytes, whereas the expression of microphthalmia-associated transcription factor (Mitf) was stimulated only in black-eyed melanocytes. CONCLUSION These results suggest that the age-related coat darkening in black-eyed mutant may be caused by the increased ability of melanocyte differentiation dependent on l-Tyr through the upregulation of tyrosinase, Tyrp1, and Mitf. This mutant mouse may be useful for animal model to clarify the mechanisms of age-related pigmentation in human skin, such as melasma and solar lentigines.
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26
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Morya VK, Dung NH, Singh BK, Lee HB, Kim EK. Homology modelling and virtual screening of P-protein in a quest for novel antimelanogenic agent and in vitro assessments. Exp Dermatol 2015; 23:838-42. [PMID: 25236473 DOI: 10.1111/exd.12549] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2014] [Indexed: 01/12/2023]
Abstract
An adequate knowledge on molecular mechanism of melanogenesis provides an opportunity to find the novel molecular targets for the discovery and development of new cosmetics. Among various genes, the OCA2 is being essential for proper melanin synthesis, and mutation or deletion of this gene leads to oculocutaneous albinism type 2. Thus, for this study, the product of this gene, that is P-protein, was targeted in quest for novel inhibitors as antimelanogenic agents. Based on pattern search of amino acid sequence and homology analysis, the protein structure was modelled. The role of this protein has been predicted as a tyrosine transporter of melanosomes. Thus, the molecular library was generated on the basis of tyrosine transporter inhibitor. Based on the dock score, 20 molecules have been considered as putative inhibitors for P-protein. Among these compounds, five molecules (compound #1, #4, #8, #13 and #17) were found to be quite effective as antimelanogenic without having any toxicity. Further investigations to establish the mechanism of action, the indirect methods such as tyrosinase assay, analysis for eumelanin and pheomelanins and investigation of mRNA levels were being carried out. The results from the studies offered a new lead in antimelanogenic therapy and may be very useful for further optimization work in developing them as novel depigmenting agents.
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Affiliation(s)
- Vivek K Morya
- Department of Biological Engineering, Inha University, Incheon, Korea
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Unrevealing the role of P-protein on melanosome biology and structure, using siRNA-mediated down regulation of OCA2. Mol Cell Biochem 2015; 403:61-71. [PMID: 25656818 DOI: 10.1007/s11010-015-2337-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 01/22/2015] [Indexed: 01/20/2023]
Abstract
The pink-eyed dilution protein (P-protein) plays a critical role in melanin synthesis in melanocytes and retinal pigment epithelium cells. Mutation in this protein may cause complete or partial albinism. Role of the P-protein ranges in melanin synthesis to maturation and trafficking of the melanosomes. The aim of the present study was to evaluate the effect of P-protein inhibition on melanosome biology by comparing the shape, size, count, and types of melanosomes in melan-a melanocytes. The cells were extensively examined by the transmission electron microscopy. The P-protein inhibition was carried by P-protein-siRNA transfection to melan-a melanocytes, B16F10 mouse melanoma, and melan-p1 cells. Measurement of melanin contents, cellular tyrosinase, and different tyrosinase related proteins were also determined to investigate the effect of P-protein siRNA transfection on melanocytes. Results suggested that the inhibition of P-protein can significantly change the melanosomal morphology, types and their respective numbers, and provided a novel strategy for the control of melanin synthesis.
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Shoji H, Kiniwa Y, Okuyama R, Yang M, Higuchi K, Mori M. A nonsense nucleotide substitution in the oculocutaneous albinism II gene underlies the original pink-eyed dilution allele (Oca2(p)) in mice. Exp Anim 2015; 64:171-9. [PMID: 25736709 PMCID: PMC4427732 DOI: 10.1538/expanim.14-0075] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The original pink-eyed dilution (p) on chromosome 7 is a very old
spontaneous mutation in mice. The oculocutaneous albinism II (Oca2) gene
has previously been identified as the p gene. Oca2
transcripts have been shown to be absent in the skin of SJL/J mice with the original
p mutant allele (Oca2p); however, the
molecular genetic lesion underlying the original Oca2p allele
has never been reported. The NCT mouse (commonly known as Nakano cataract mouse) has a
pink-eyed dilution phenotype, which prompted us to undertake a molecular genetic analysis
of the Oca2 gene of this strain. Our genetic linkage analysis suggests
that the locus for the pink-eyed dilution phenotype of NCT is tightly linked to the
Oca2 locus. PCR cloning and nucleotide sequence analysis indicates that
the NCT mouse has a nonsense nucleotide substitution at exon 7 of the
Oca2 gene. Examination of three mouse strains (NZW/NSlc, SJL/J, and
129X1/SvJJmsSlc) with the original Oca2p allele revealed the
presence of a nonsense nucleotide substitution identical to that in the NCT strain. RT-PCR
analysis revealed that the Oca2 transcripts were absent in the skin of
NCT mice, suggesting intervention of the nonsense-mediated mRNA decay pathway.
Collectively, the data in this study indicate that the nonsense nucleotide substitution in
the Oca2 gene underlies the Oca2p allele. Our
data also indicate that the NCT mouse can be used not only as a cataract model, but also
as a model for human type II oculocutaneous albinism.
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Affiliation(s)
- Haruka Shoji
- Department of Aging Biology, Institute of Pathogenesis and Disease Prevention, Shinshu University Graduate School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano 390-8621, Japan
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Kondo T, Namiki T, Coelho SG, Valencia JC, Hearing VJ. Oculocutaneous albinism: Developing novel antibodies targeting the proteins associated with OCA2 and OCA4. J Dermatol Sci 2015; 77:21-7. [DOI: 10.1016/j.jdermsci.2014.11.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2014] [Revised: 10/05/2014] [Accepted: 11/10/2014] [Indexed: 12/31/2022]
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Bellono NW, Escobar IE, Lefkovith AJ, Marks MS, Oancea E. An intracellular anion channel critical for pigmentation. eLife 2014; 3:e04543. [PMID: 25513726 PMCID: PMC4270065 DOI: 10.7554/elife.04543] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/07/2014] [Indexed: 12/28/2022] Open
Abstract
Intracellular ion channels are essential regulators of organellar and cellular function, yet the molecular identity and physiological role of many of these channels remains elusive. In particular, no ion channel has been characterized in melanosomes, organelles that produce and store the major mammalian pigment melanin. Defects in melanosome function cause albinism, characterized by vision and pigmentation deficits, impaired retinal development, and increased susceptibility to skin and eye cancers. The most common form of albinism is caused by mutations in oculocutaneous albinism II (OCA2), a melanosome-specific transmembrane protein with unknown function. Here we used direct patch-clamp of skin and eye melanosomes to identify a novel chloride-selective anion conductance mediated by OCA2 and required for melanin production. Expression of OCA2 increases organelle pH, suggesting that the chloride channel might regulate melanin synthesis by modulating melanosome pH. Thus, a melanosomal anion channel that requires OCA2 is essential for skin and eye pigmentation.
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Affiliation(s)
- Nicholas W Bellono
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, United States
| | - Iliana E Escobar
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, United States
| | - Ariel J Lefkovith
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, United States
| | - Michael S Marks
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, United States
| | - Elena Oancea
- Department of Molecular Pharmacology, Physiology and Biotechnology, Brown University, Providence, United States
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31
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Visser M, Kayser M, Grosveld F, Palstra RJ. Genetic variation in regulatory DNA elements: the case of OCA2 transcriptional regulation. Pigment Cell Melanoma Res 2014; 27:169-77. [PMID: 24387780 DOI: 10.1111/pcmr.12210] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 12/20/2013] [Indexed: 12/16/2022]
Abstract
Mutations within the OCA2 gene or the complete absence of the OCA2 protein leads to oculocutaneous albinism type 2. The OCA2 protein plays a central role in melanosome biogenesis, and it is a strong determinant of the eumelanin content in melanocytes. Transcript levels of the OCA2 gene are strongly correlated with pigmentation intensities. Recent studies demonstrated that the transcriptional level of OCA2 is to a large extent determined by the noncoding SNP rs12913832 located 21.5 kb upstream of the OCA2 gene promoter. In this review, we discuss current hypotheses and the available data on the mechanism of OCA2 transcriptional regulation and how this is influenced by genetic variation. Finally, we will explore how future epigenetic studies can be used to advance our insight into the functional biology that connects genetic variation to human pigmentation.
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Affiliation(s)
- Mijke Visser
- Department of Forensic Molecular Biology, Erasmus MC University Medical Center Rotterdam, Rotterdam, The Netherlands
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32
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Lysophospholipid-containing membranes modulate the fibril formation of the repeat domain of a human functional amyloid, pmel17. J Mol Biol 2014; 426:4074-4086. [PMID: 25451784 DOI: 10.1016/j.jmb.2014.10.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Revised: 09/23/2014] [Accepted: 10/08/2014] [Indexed: 11/23/2022]
Abstract
Pmel17 is an important protein for pigmentation in human skin and eyes. Proteolytic fragments from Pmel17 form fibrils upon which melanin is deposited in melanosomes. The repeat domain (RPT) derived from Pmel17 only forms fibrils under acidic melanosomal conditions. Here, we examined the effects of lipids on RPT aggregation to explore whether intramelanosomal vesicles can facilitate fibrillogenesis. Using transmission electron microscopy, circular dichroism, and fluorescence spectroscopy, we monitored fibril formation at the ultrastructural, secondary conformational, and local levels, respectively. Phospholipid vesicles and lysophospholipid (lysolipid) micelles were employed as membrane mimics. The surfactant-like lysolipids are particularly pertinent due to their high content in melanosomal membranes. Interestingly, RPT aggregation kinetics were influenced only by lysolipid-containing phospholipid vesicles. While both vesicles containing either anionic lysophosphatidylglycerol (LPG) or zwitterionic lysophosphatidylcholine (LPC) stimulate aggregation, LPG exerted a greater effect on reducing the apparent nucleation time. A detailed comparison showed distinct behaviors of LPG versus LPC monomers and micelles plausibly originating from their headgroup hydrogen bonding capabilities. Acceleration and retardation of aggregation were observed for LPG monomers and micelles, respectively. Because a specific interaction between LPG and RPT was identified by intrinsic W423 fluorescence and induced α-helical structure, it is inferred that binding of LPG near the C-terminal amyloid core initiates intermolecular association, whereas stabilization of α-helical conformation inhibits β-sheet formation. Contrastingly, LPC promotes RPT aggregation at both submicellar and micellar concentrations via non-specific binding with undetectable secondary structural change. Our findings suggest that protein-lysolipid interactions within melanosomes may regulate amyloid formation in vivo.
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Kraft S, Granter SR. Molecular pathology of skin neoplasms of the head and neck. Arch Pathol Lab Med 2014; 138:759-87. [PMID: 24878016 DOI: 10.5858/arpa.2013-0157-ra] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
CONTEXT Skin neoplasms include the most common malignancies affecting humans. Many show an ultraviolet (UV)-induced pathogenesis and often affect the head and neck region. OBJECTIVE To review literature on cutaneous neoplasms that show a predilection for the head and neck region and that are associated with molecular alterations. DATA SOURCES Literature review. CONCLUSIONS Common nonmelanoma skin cancers, such as basal and squamous cell carcinomas, show a UV-induced pathogenesis. Basal cell carcinomas are characterized by molecular alterations of the Hedgehog pathway, affecting patched and smoothened genes. While squamous cell carcinomas show UV-induced mutations in several genes, driver mutations are only beginning to be identified. In addition, certain adnexal neoplasms also predominantly affect the head and neck region and show interesting, recently discovered molecular abnormalities, or are associated with hereditary conditions whose molecular genetic pathogenesis is well understood. Furthermore, recent advances have led to an increased understanding of the molecular pathogenesis of melanoma. Certain melanoma subtypes, such as lentigo maligna melanoma and desmoplastic melanoma, which are more often seen on the chronically sun-damaged skin of the head and neck, show differences in their molecular signature when compared to the other more common subtypes, such as superficial spreading melanoma, which are more prone to occur at sites with acute intermittent sun damage. In summary, molecular alterations in cutaneous neoplasms of the head and neck are often related to UV exposure. Their molecular footprint often reflects the histologic tumor type, and familiarity with these changes will be increasingly necessary for diagnostic and therapeutic considerations.
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Affiliation(s)
- Stefan Kraft
- From the Department of Pathology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts (Dr Kraft); and the Department of Pathology, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts (Dr Granter)
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Bellono NW, Oancea EV. Ion transport in pigmentation. Arch Biochem Biophys 2014; 563:35-41. [PMID: 25034214 DOI: 10.1016/j.abb.2014.06.020] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/01/2014] [Accepted: 06/03/2014] [Indexed: 12/01/2022]
Abstract
Skin melanocytes and ocular pigment cells contain specialized organelles called melanosomes, which are responsible for the synthesis of melanin, the major pigment in mammals. Defects in the complex mechanisms involved in melanin synthesis and regulation result in vision and pigmentation deficits, impaired development of the visual system, and increased susceptibility to skin and eye cancers. Ion transport across cellular membranes is critical for many biological processes, including pigmentation, but the molecular mechanisms by which it regulates melanin synthesis, storage, and transfer are not understood. In this review we first discuss ion channels and transporters that function at the plasma membrane of melanocytes; in the second part we consider ion transport across the membrane of intracellular organelles, with emphasis on melanosomes. We discuss recently characterized lysosomal and endosomal ion channels and transporters associated with pigmentation phenotypes. We then review the evidence for melanosomal channels and transporters critical for pigmentation, discussing potential molecular mechanisms mediating their function. The studies investigating ion transport in pigmentation physiology open new avenues for future research and could reveal novel molecular mechanisms underlying melanogenesis.
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Affiliation(s)
- Nicholas W Bellono
- Department of Molecular Physiology, Pharmacology and Biotechnology, Brown University, Providence, RI 02912, United States
| | - Elena V Oancea
- Department of Molecular Physiology, Pharmacology and Biotechnology, Brown University, Providence, RI 02912, United States.
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35
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Shah SA, Din SU, Raheem N, Daud S, Mubeen J, Nadeem A, Tayyab M, Baloch DM, Babar ME, Ahmad J. Identification of a novel mutation (p.Ile198Thr) in gene TYR in a Pakistani family with nonsyndromic oculocutaneous albinism. Clin Exp Dermatol 2014; 39:646-8. [PMID: 24934919 DOI: 10.1111/ced.12382] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2014] [Indexed: 11/28/2022]
Abstract
The TYR gene (MIM #6069333) is located at position 11q14.3 on the human chromosome, and encodes tyrosinase, which is expressed in melanocytes and controls the biosynthesis of melanin. Most TYR mutations eliminate the activity of tyrosinase, preventing melanocytes from producing any melanin throughout life. People with this form of albinism have white hair, light-coloured eyes and very pale skin. Some mutations in TYR reduce but do not completely eliminate tyrosinase activity, and allow some melanin to be produced. We report a Pakistani family with four members affected by oculocutaneous albinism (OCA). Blood samples were collected from all affected individuals, normal siblings and their parents. Genomic DNA was extracted, and sequence analysis of all the coding exons and adjacent intronic sequences of TYR was performed, which identified a novel missense substitution (p.Ile198Thr). Sequencing of TYR in 90 unrelated healthy individuals showed no sequence variant at this location. Our study expands the mutational spectrum of OCA1.
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Affiliation(s)
- S A Shah
- Institute of Biochemistry and Biotechnology (IBBt), UVAS, Lahore, Pakistan
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36
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Beirl AJ, Linbo TH, Cobb MJ, Cooper CD. oca2regulation of chromatophore differentiation and number is cell type specific in zebrafish. Pigment Cell Melanoma Res 2014; 27:178-89. [DOI: 10.1111/pcmr.12205] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2013] [Accepted: 11/28/2013] [Indexed: 11/29/2022]
Affiliation(s)
- Alisha J. Beirl
- School of Molecular Biosciences; Washington State University Vancouver; Vancouver WA USA
| | - Tor H. Linbo
- Department of Biological Structure; University of Washington; Seattle WA USA
| | - Marea J. Cobb
- School of Molecular Biosciences; Washington State University Vancouver; Vancouver WA USA
| | - Cynthia D. Cooper
- School of Molecular Biosciences; Washington State University Vancouver; Vancouver WA USA
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37
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Dolinska MB, Kovaleva E, Backlund P, Wingfield PT, Brooks BP, Sergeev YV. Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity. PLoS One 2014; 9:e84494. [PMID: 24392141 PMCID: PMC3879332 DOI: 10.1371/journal.pone.0084494] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 11/14/2013] [Indexed: 01/09/2023] Open
Abstract
Background Tyrosinase (TYR) catalyzes the rate-limiting, first step in melanin production and its gene (TYR) is mutated in many cases of oculocutaneous albinism (OCA1), an autosomal recessive cause of childhood blindness. Patients with reduced TYR activity are classified as OCA1B; some OCA1B mutations are temperature-sensitive. Therapeutic research for OCA1 has been hampered, in part, by the absence of purified, active, recombinant wild-type and mutant human enzymes. Methodology/Principal Findings The intra-melanosomal domain of human tyrosinase (residues 19–469) and two OCA1B related temperature-sensitive mutants, R422Q and R422W were expressed in insect cells and produced in T. ni larvae. The short trans-membrane fragment was deleted to avoid potential protein insolubility, while preserving all other functional features of the enzymes. Purified tyrosinase was obtained with a yield of >1 mg per 10 g of larval biomass. The protein was a monomeric glycoenzyme with maximum enzyme activity at 37°C and neutral pH. The two purified mutants when compared to the wild-type protein were less active and temperature sensitive. These differences are associated with conformational perturbations in secondary structure. Conclusions/Significance The intramelanosomal domains of recombinant wild-type and mutant human tyrosinases are soluble monomeric glycoproteins with activities which mirror their in vivo function. This advance allows for the structure – function analyses of different mutant TYR proteins and correlation with their corresponding human phenotypes; it also provides an important tool to discover drugs that may improve tyrosinase activity and treat OCA1.
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Affiliation(s)
- Monika B. Dolinska
- National Eye Institute, NIH, Bethesda, Maryland, United States of America
| | - Elena Kovaleva
- Chesapeake PERL, Savage, Maryland, United States of America
| | - Peter Backlund
- Eunice Kennedy Shriver National Institute Child Health and Human Development, NIH, Bethesda, Maryland, United States of America
| | - Paul T. Wingfield
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, NIH, Bethesda, Maryland, United States of America
| | - Brian P. Brooks
- National Eye Institute, NIH, Bethesda, Maryland, United States of America
- * E-mail: (BPB); (YVS)
| | - Yuri V. Sergeev
- National Eye Institute, NIH, Bethesda, Maryland, United States of America
- * E-mail: (BPB); (YVS)
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d'Ischia M, Wakamatsu K, Napolitano A, Briganti S, Garcia-Borron JC, Kovacs D, Meredith P, Pezzella A, Picardo M, Sarna T, Simon JD, Ito S. Melanins and melanogenesis: methods, standards, protocols. Pigment Cell Melanoma Res 2013; 26:616-33. [PMID: 23710556 DOI: 10.1111/pcmr.12121] [Citation(s) in RCA: 281] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 05/17/2013] [Indexed: 01/03/2023]
Abstract
Despite considerable advances in the past decade, melanin research still suffers from the lack of universally accepted and shared nomenclature, methodologies, and structural models. This paper stems from the joint efforts of chemists, biochemists, physicists, biologists, and physicians with recognized and consolidated expertise in the field of melanins and melanogenesis, who critically reviewed and experimentally revisited methods, standards, and protocols to provide for the first time a consensus set of recommended procedures to be adopted and shared by researchers involved in pigment cell research. The aim of the paper was to define an unprecedented frame of reference built on cutting-edge knowledge and state-of-the-art methodology, to enable reliable comparison of results among laboratories and new progress in the field based on standardized methods and shared information.
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Affiliation(s)
- Marco d'Ischia
- Department of Chemical Sciences, University of Naples Federico II, Naples, Italy.
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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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40
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Watt B, van Niel G, Raposo G, Marks MS. PMEL: a pigment cell-specific model for functional amyloid formation. Pigment Cell Melanoma Res 2013; 26:300-15. [PMID: 23350640 DOI: 10.1111/pcmr.12067] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2012] [Accepted: 01/15/2013] [Indexed: 12/15/2022]
Abstract
PMEL is a pigment cell-specific protein responsible for the formation of fibrillar sheets within the pigment organelle, the melanosome. The fibrillar sheets serve as a template upon which melanins polymerize as they are synthesized. The PMEL fibrils are required for optimal pigment cell function, as animals that either lack PMEL expression or express mutant PMEL variants show varying degrees of hypopigmentation and pigment cell inviability. The PMEL fibrils have biophysical properties of amyloid, a protein fold that is frequently associated with neurodegenerative and other diseases. However, PMEL is one of a growing number of non-pathogenic amyloid proteins that contribute to the function of the cell and/or organism that produces them. Understanding how PMEL generates amyloid in a non-pathogenic manner might provide insights into how to avoid toxicity due to pathological amyloid formation. In this review, we summarize and reconcile data concerning the fate of PMEL from its site of synthesis in the endoplasmic reticulum to newly formed melanosomes and the role of distinct PMEL subdomains in trafficking and amyloid fibril formation. We then discuss how its progression through the secretory pathway into the endosomal system might allow for the regulated and non-toxic conversion of PMEL into an ordered amyloid polymer.
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Affiliation(s)
- Brenda Watt
- Department of Pathology and Laboratory Medicine, Department of Physiology, and Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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41
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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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42
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Tuli AM, Valenzuela RK, Kamugisha E, Brilliant MH. Albinism and disease causing pathogens in Tanzania: Are alleles that are associated with OCA2 being maintained by balancing selection? Med Hypotheses 2012; 79:875-8. [DOI: 10.1016/j.mehy.2012.09.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 08/27/2012] [Accepted: 09/20/2012] [Indexed: 10/27/2022]
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43
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Jaworek TJ, Kausar T, Bell SM, Tariq N, Maqsood MI, Sohail A, Ali M, Iqbal F, Rasool S, Riazuddin S, Shaikh RS, Ahmed ZM. Molecular genetic studies and delineation of the oculocutaneous albinism phenotype in the Pakistani population. Orphanet J Rare Dis 2012; 7:44. [PMID: 22734612 PMCID: PMC3537634 DOI: 10.1186/1750-1172-7-44] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Accepted: 04/30/2012] [Indexed: 02/01/2023] Open
Abstract
Background Oculocutaneous albinism (OCA) is caused by a group of genetically heterogeneous inherited defects that result in the loss of pigmentation in the eyes, skin and hair. Mutations in the TYR, OCA2, TYRP1 and SLC45A2 genes have been shown to cause isolated OCA. No comprehensive analysis has been conducted to study the spectrum of OCA alleles prevailing in Pakistani albino populations. Methods We enrolled 40 large Pakistani families and screened them for OCA genes and a candidate gene, SLC24A5. Protein function effects were evaluated using in silico prediction algorithms and ex vivo studies in human melanocytes. The effects of splice-site mutations were determined using an exon-trapping assay. Results Screening of the TYR gene revealed four known (p.Arg299His, p.Pro406Leu, p.Gly419Arg, p.Arg278*) and three novel mutations (p.Pro21Leu, p.Cys35Arg, p.Tyr411His) in ten families. Ex vivo studies revealed the retention of an EGFP-tagged mutant (p.Pro21Leu, p.Cys35Arg or p.Tyr411His) tyrosinase in the endoplasmic reticulum (ER) at 37°C, but a significant fraction of p.Cys35Arg and p.Tyr411His left the ER in cells grown at a permissive temperature (31°C). Three novel (p.Asp486Tyr, p.Leu527Arg, c.1045-15 T > G) and two known mutations (p.Pro743Leu, p.Ala787Thr) of OCA2 were found in fourteen families. Exon-trapping assays with a construct containing a novel c.1045-15 T > G mutation revealed an error in splicing. No mutation in TYRP1, SLC45A2, and SLC24A5 was found in the remaining 16 families. Clinical evaluation of the families segregating either TYR or OCA2 mutations showed nystagmus, photophobia, and loss of pigmentation in the skin or hair follicles. Most of the affected individuals had grayish-blue colored eyes. Conclusions Our results show that ten and fourteen families harbored mutations in the TYR and OCA2 genes, respectively. Our findings, along with the results of previous studies, indicate that the p.Cys35Arg, p.Arg278* and p.Gly419Arg alleles of TYR and the p.Asp486Tyr and c.1045-15 T > G alleles of OCA2 are the most common causes of OCA in Pakistani families. To the best of our knowledge, this study represents the first documentation of OCA2 alleles in the Pakistani population. A significant proportion of our cohort did not have mutations in known OCA genes. Overall, our study contributes to the development of genetic testing protocols and genetic counseling for OCA in Pakistani families.
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Affiliation(s)
- Thomas J Jaworek
- Division of Pediatric Ophthalmology, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA
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Pośpiech E, Draus-Barini J, Kupiec T, Wojas-Pelc A, Branicki W. Prediction of Eye Color from Genetic Data Using Bayesian Approach*. J Forensic Sci 2012; 57:880-6. [DOI: 10.1111/j.1556-4029.2012.02077.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Lee DJ, Lee J, Ha J, Park KC, Ortonne JP, Kang HY. Defective barrier function in melasma skin. J Eur Acad Dermatol Venereol 2011; 26:1533-7. [PMID: 22077137 DOI: 10.1111/j.1468-3083.2011.04337.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Melasma is characterized by increased pigmentation and photodamaged features, which include solar elastosis. Recently, we detected the downregulation of the genes most associated with lipid metabolism using microarray analysis in melasma. These findings suggested that lesional skin may have different biophysical characteristics, and, in particular, an altered skin barrier function. OBJECTIVE To determine the cutaneous biophysical characteristics of melasma. METHODS The melanin index, erythema index, stratum corneum hydration, sebum content and transepidermal water loss (TEWL) were measured for lesional and perilesional normal skin of 16 melasma patients and then compared. In addition, a skin biopsy was performed on 11 of the 16 study subjects to measure stratum corneum thickness and to study the protein expressions of PPAR-α and ALOX15B. RESULTS Melanin index, erythema index and stratum corneum hydration were significantly higher in lesional skin than in perilesional normal skin. No significant difference was found between lesional and normal skin in terms of basal TEWL level or sebum content. However, the rate of TEWL after barrier perturbation was significantly higher for lesional skin, and the barrier recovery rate was significantly delayed. Furthermore, a trend towards thinned stratum corneum was observed for lesional skin, and this was correlated with barrier recovery rate. The expressions of PPAR-α and ALOX15B were variable in the samples. CONCLUSIONS Melasma skin is characterized by impaired stratum corneum integrity and a delayed barrier recovery rate.
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Affiliation(s)
- D J Lee
- Department of Dermatology, Ajou University School of Medicine, Suwon, Korea
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McGlinchey RP, Yap TL, Lee JC. The yin and yang of amyloid: insights from α-synuclein and repeat domain of Pmel17. Phys Chem Chem Phys 2011; 13:20066-75. [PMID: 21993592 DOI: 10.1039/c1cp21376h] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Amyloid has been traditionally viewed in the context of disease. However, the emerging concept of 'functional amyloid' has taken a new direction into how we view amyloid. Recent studies have identified amyloid fibrils ranging from bacteria to humans that have a beneficial role, instead of being associated with a misfolded state that has been implicated in diseases such as Alzheimer's, Parkinson's and prion diseases. Here, we review our work on two human amyloidogenic polypeptides, one associated with Parkinson's disease, α-synuclein (α-syn), and the other important for melanin synthesis, the repeat domain (RPT) from Pmel17. Particularly, we focused our attention on spectroscopic studies of protein conformation and dynamics and their impact on α-syn amyloid formation and for RPT, we discussed the strict pH dependence of amyloid formation and its role in melanin biosynthesis.
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Affiliation(s)
- Ryan P McGlinchey
- Laboratory of Molecular Biophysics, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA
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Wilson RT, Roff AN, Dai PJ, Fortugno T, Douds J, Chen G, Grove GL, Nikiforova SO, Barnholtz-Sloan J, Frudakis T, Chinchilli VM, Hartman TJ, Demers LM, Shriver MD, Canfield VA, Cheng KC. Genetic Ancestry, Skin Reflectance and Pigmentation Genotypes in Association with Serum Vitamin D Metabolite Balance. Horm Mol Biol Clin Investig 2011; 7:279-293. [PMID: 23525585 DOI: 10.1515/hmbci.2011.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Lower serum vitamin D (25(OH)D) among individuals with African ancestry is attributed primarily to skin pigmentation. However, the influence of genetic polymorphisms controlling for skin melanin content has not been investigated. Therefore, we investigated differences in non-summer serum vitamin D metabolites according to self-reported race, genetic ancestry, skin reflectance and key pigmentation genes (SLC45A2 and SLC24A5). MATERIALS AND METHODS Healthy individuals reporting at least half African American or half European American heritage were frequency matched to one another on age (+/- 2 years) and sex. 176 autosomal ancestry informative markers were used to estimate genetic ancestry. Melanin index was measured by reflectance spectrometry. Serum vitamin D metabolites (25(OH)D3, 25(OH)D 2 and 24,25(OH)2D3) were determined by high performance liquid chromatography (HPLC) tandem mass spectrometry. Percent 24,25(OH)2D3 was calculated as a percent of the parent metabolite (25(OH)D3). Stepwise and backward selection regression models were used to identify leading covariates. RESULTS Fifty African Americans and 50 European Americans participated in the study. Compared with SLC24A5 111Thr homozygotes, individuals with the SLC24A5 111Thr/Ala and 111Ala/Ala genotypes had respectively lower levels of 25(OH)D3 (23.0 and 23.8 nmol/L lower, p-dominant=0.007), and percent 24,25(OH)2D3 (4.1 and 5.2 percent lower, p-dominant=0.003), controlling for tanning bed use, vitamin D/fish oil supplement intake, race/ethnicity, and genetic ancestry. Results were similar with melanin index adjustment, and were not confounded by glucocorticoid, oral contraceptive, or statin use. CONCLUSIONS The SLC24A5 111Ala allele was associated with lower serum vitamin 25(OH)D3 and lower percent 24,25(OH)2D3, independently from melanin index and West African genetic ancestry.
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Affiliation(s)
- Robin Taylor Wilson
- Penn State Hershey College of Medicine, and Penn State Hershey Cancer Institute, The Pennsylvania State University, Hershey, Pennsylvania, U.S.A
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Pośpiech E, Draus-Barini J, Kupiec T, Wojas-Pelc A, Branicki W. Gene-gene interactions contribute to eye colour variation in humans. J Hum Genet 2011; 56:447-55. [PMID: 21471978 DOI: 10.1038/jhg.2011.38] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Prediction of phenotypes from genetic data is considered to be the first practical application of data gained from association studies, with potential importance for medicine and the forensic sciences. Multiple genes and polymorphisms have been found to be associated with variation in human pigmentation. Their analysis enables prediction of blue and brown eye colour with a reasonably high accuracy. More accurate prediction, especially in the case of intermediate eye colours, may require better understanding of gene-gene interactions affecting this polygenic trait. Using multifactor dimensionality reduction and logistic regression methods, a study of gene-gene interactions was conducted based on variation in 11 known pigmentation genes examined in a cohort of 718 individuals of European descent. The study revealed significant interactions of a redundant character between the HERC2 and OCA2 genes affecting determination of hazel eye colour and between HERC2 and SLC24A4 affecting determination of blue eye colour. Our research indicates interactive effects of a synergistic character between HERC2 and OCA2, and also provides evidence for a novel strong synergistic interaction between HERC2 and TYRP1, both affecting determination of green eye colour.
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Affiliation(s)
- Ewelina Pośpiech
- Section of Forensic Genetics, Institute of Forensic Research, Kraków, Poland
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Abstract
Coat colors are determined by melanin (eumelanin and pheomelanin). Melanin is synthesized in melanocytes and accumulates in special organelles, melanosomes, which upon maturation are transferred to keratinocytes. Melanocytes differentiate from undifferentiated precursors, called melanoblasts, which are derived from neural crest cells. Melanoblast/melanocyte proliferation and differentiation are regulated by the tissue environment, especially by keratinocytes, which synthesize endothelins, steel factor, hepatocyte growth factor, leukemia inhibitory factor and granulocyte-macrophage colony-stimulating factor. Melanocyte differentiation is also stimulated by alpha-melanocyte stimulating hormone; in the mouse, however, this hormone is likely carried through the bloodstream and not produced locally in the skin. Melanoblast migration, proliferation and differentiation are also regulated by many coat color genes otherwise known for their ability to regulate melanosome formation and maturation, pigment type switching and melanosome distribution and transfer. Thus, melanocyte proliferation and differentiation are not only regulated by genes encoding typical growth factors and their receptors but also by genes classically known for their role in pigment formation.
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Affiliation(s)
- Tomohisa Hirobe
- Radiation Effect Mechanisms Research Group, National Institute of Radiological Sciences, Anagawa, Inage-ku, Chiba, Japan Graduate School of Science, Chiba University, Yayoi-cho, Inage-ku, Chiba, Japan.
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McGlinchey RP, Shewmaker F, Hu KN, McPhie P, Tycko R, Wickner RB. Repeat domains of melanosome matrix protein Pmel17 orthologs form amyloid fibrils at the acidic melanosomal pH. J Biol Chem 2011; 286:8385-8393. [PMID: 21148556 PMCID: PMC3048723 DOI: 10.1074/jbc.m110.197152] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2010] [Revised: 12/01/2010] [Indexed: 01/22/2023] Open
Abstract
Most amyloids are pathological, but fragments of Pmel17 form a functional amyloid in vertebrate melanosomes essential for melanin synthesis and deposition. We previously reported that only at the mildly acidic pH (4-5.5) typical of melanosomes, the repeat domain (RPT) of human Pmel17 can form amyloid in vitro. Combined with the known presence of RPT in the melanosome filaments and the requirement of this domain for filament formation, we proposed that RPT may be the core of the amyloid formed in vivo. Although most of Pmel17 is highly conserved across a broad range of vertebrates, the RPT domains vary dramatically, with no apparent homology in some cases. Here, we report that the RPT domains of mouse and zebrafish, as well as a small splice variant of human Pmel17, all form amyloid specifically at mildly acid pH (pH ∼5.0). Protease digestion, mass per unit length measurements, and solid-state NMR experiments suggest that amyloid of the mouse RPT has an in-register parallel β-sheet architecture with two RPT molecules per layer, similar to amyloid of the Aβ peptide. Although there is no sequence conservation between human and zebrafish RPT, amyloid formation at acid pH is conserved.
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Affiliation(s)
| | | | - Kan-Nian Hu
- Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-0830
| | - Peter McPhie
- From the Laboratory of Biochemistry and Genetics and
| | - Robert Tycko
- Laboratory of Chemical Physics, NIDDK, National Institutes of Health, Bethesda, Maryland 20892-0830
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