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Slominski RM, Kim TK, Janjetovic Z, Brożyna AA, Podgorska E, Dixon KM, Mason RS, Tuckey RC, Sharma R, Crossman DK, Elmets C, Raman C, Jetten AM, Indra AK, Slominski AT. Malignant Melanoma: An Overview, New Perspectives, and Vitamin D Signaling. Cancers (Basel) 2024; 16:2262. [PMID: 38927967 PMCID: PMC11201527 DOI: 10.3390/cancers16122262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2024] [Revised: 06/09/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024] Open
Abstract
Melanoma, originating through malignant transformation of melanin-producing melanocytes, is a formidable malignancy, characterized by local invasiveness, recurrence, early metastasis, resistance to therapy, and a high mortality rate. This review discusses etiologic and risk factors for melanoma, diagnostic and prognostic tools, including recent advances in molecular biology, omics, and bioinformatics, and provides an overview of its therapy. Since the incidence of melanoma is rising and mortality remains unacceptably high, we discuss its inherent properties, including melanogenesis, that make this disease resilient to treatment and propose to use AI to solve the above complex and multidimensional problems. We provide an overview on vitamin D and its anticancerogenic properties, and report recent advances in this field that can provide solutions for the prevention and/or therapy of melanoma. Experimental papers and clinicopathological studies on the role of vitamin D status and signaling pathways initiated by its active metabolites in melanoma prognosis and therapy are reviewed. We conclude that vitamin D signaling, defined by specific nuclear receptors and selective activation by specific vitamin D hydroxyderivatives, can provide a benefit for new or existing therapeutic approaches. We propose to target vitamin D signaling with the use of computational biology and AI tools to provide a solution to the melanoma problem.
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Affiliation(s)
- Radomir M. Slominski
- Department of Rheumatology and Clinical Immunology, Department of Medicine, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Tae-Kang Kim
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.-K.K.); (Z.J.); (E.P.); (C.E.); (C.R.)
| | - Zorica Janjetovic
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.-K.K.); (Z.J.); (E.P.); (C.E.); (C.R.)
| | - Anna A. Brożyna
- Department of Human Biology, Institute of Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, 87-100 Torun, Poland;
| | - Ewa Podgorska
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.-K.K.); (Z.J.); (E.P.); (C.E.); (C.R.)
| | - Katie M. Dixon
- School of Medical Sciences, The University of Sydney, Sydney, NSW 2050, Australia; (K.M.D.); (R.S.M.)
| | - Rebecca S. Mason
- School of Medical Sciences, The University of Sydney, Sydney, NSW 2050, Australia; (K.M.D.); (R.S.M.)
| | - Robert C. Tuckey
- School of Molecular Sciences, University of Western Australia, Perth, WA 6009, Australia;
| | - Rahul Sharma
- Department of Biomedical Informatics and Data Science, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - David K. Crossman
- Department of Genetics and Bioinformatics, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Craig Elmets
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.-K.K.); (Z.J.); (E.P.); (C.E.); (C.R.)
| | - Chander Raman
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.-K.K.); (Z.J.); (E.P.); (C.E.); (C.R.)
| | - Anton M. Jetten
- Cell Biology Section, NIEHS—National Institutes of Health, Research Triangle Park, NC 27709, USA;
| | - Arup K. Indra
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR 97331, USA
- Department of Dermatology, Oregon Health & Science University, Portland, OR 97239, USA
- Knight Cancer Institute, Oregon Health & Science University, Portland, OR 97239, USA
| | - Andrzej T. Slominski
- Department of Dermatology, School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA; (T.-K.K.); (Z.J.); (E.P.); (C.E.); (C.R.)
- Comprehensive Cancer Center, University of Alabama at Birmingham, Birmingham, AL 35294, USA
- Pathology and Laboratory Medicine Service, Veteran Administration Medical Center, Birmingham, AL 35233, USA
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2
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Mueller A, Lam I, Kishor K, Lee RK, Bhattacharya S. Secondary glaucoma: Toward interventions based on molecular underpinnings. WIREs Mech Dis 2024; 16:e1628. [PMID: 37669762 DOI: 10.1002/wsbm.1628] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 09/07/2023]
Abstract
Glaucoma is a heterogeneous group of progressive diseases that leads to irreversible blindness. Secondary glaucoma refers to glaucoma caused by a known underlying condition. Pseudoexfoliation and pigment dispersion syndromes are common causes of secondary glaucoma. Their respective deposits may obstruct the trabecular meshwork, leading to aqueous humor outflow resistance, ocular hypertension, and optic neuropathy. There are no disease-specific interventions available for either. Pseudoexfoliation syndrome is characterized by fibrillar deposits (pseudoexfoliative material) on anterior segment structures. Over a decade of multiomics analyses taken together with the current knowledge on pseudoexfoliative glaucoma warrant a re-think of mechanistic possibilities. We propose that the presence of nucleation centers (e.g., vitamin D binding protein), crosslinking enzymes (e.g., transglutaminase 2), aberrant extracellular matrix, flawed endocytosis, and abnormal aqueous-blood barrier contribute to the formation of proteolytically resistant pseudoexfoliative material. Pigment dispersion syndrome is characterized by abnormal iridolenticular contact that disrupts iris pigment epithelium and liberates melanin granules. Iris melanogenesis is aberrant in this condition. Cytotoxic melanogenesis intermediates leak out of melanosomes and cause iris melanocyte and pigment epithelium cell death. Targeting melanogenesis can likely decrease the risk of pigmentary glaucoma. Skin and melanoma research provides insights into potential therapeutics. We propose that specific prostanoid agonists and fenofibrates may reduce melanogenesis by inhibiting cholesterol internalization and de novo synthesis. Additionally, melatonin is a potent melanogenesis suppressor, antioxidant, and hypotensive agent, rendering it a valuable agent for pigmentary glaucoma. In pseudoexfoliative glaucoma, where environmental insults drive pseudoexfoliative material formation, melatonin's antioxidant and hypotensive properties may offer adjunct therapeutic benefits. This article is categorized under: Neurological Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Anna Mueller
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
- Herbert Wertheim College of Medicine, Florida International University, Miami, Florida, USA
| | - Isabel Lam
- Idaho College of Osteopathic Medicine, Meridian, Idaho, USA
| | - Krishna Kishor
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
- Miami Integrative Metabolomics Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Richard K Lee
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
- Miami Integrative Metabolomics Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Sanjoy Bhattacharya
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
- Miami Integrative Metabolomics Research Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, USA
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3
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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: 3] [Impact Index Per Article: 3.0] [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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4
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Zhang S, De Leon Rodriguez LM, Li FF, Huang R, Leung IKH, Harris PWR, Brimble MA. A novel tyrosine hyperoxidation enables selective peptide cleavage. Chem Sci 2022; 13:2753-2763. [PMID: 35356671 PMCID: PMC8890263 DOI: 10.1039/d1sc06216f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 02/10/2022] [Indexed: 11/21/2022] Open
Abstract
A novel tyrosine hyperoxidation enabling selective peptide cleavage is reported. The scission of the N-terminal amide bond of tyrosine was achieved with Dess–Martin periodinane under mild conditions, generating a C-terminal peptide fragment bearing the unprecedented hyperoxidized tyrosine motif, 4,5,6,7-tetraoxo-1H-indole-2-carboxamide, along with an intact N-terminal peptide fragment. This reaction proceeds with high site-selectivity for tyrosine and exhibits broad substrate scope for various peptides, including those containing post-translational modifications. More importantly, this oxidative cleavage was successfully applied to enable sequencing of three naturally occurring cyclic peptides, including one depsipeptide and one lipopeptide. The linearized peptides generated from the cleavage reaction significantly simplify cyclic peptide sequencing by MS/MS, thus providing a robust tool to facilitate rapid sequence determination of diverse cyclic peptides containing tyrosine. Furthermore, the highly electrophilic nature of the hyperoxidized tyrosine unit disclosed in this work renders it an important electrophilic target for the selective bioconjugation or synthetic manipulation of peptides containing this unit. A Tyr-selective peptide cleavage was reported using Dess–Martin periodinane. The cleavage generates an unprecedented hyperoxidized tyrosine motif in the C-terminal fragment and showed excellent site-specificity and broad scope for various peptides.![]()
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Affiliation(s)
- Shengping Zhang
- School of Chemical Sciences, The University of Auckland 23 Symonds St Auckland 1010 New Zealand .,School of Biological Sciences, The University of Auckland 3A Symonds St Auckland 1010 New Zealand
| | | | - Freda F Li
- School of Chemical Sciences, The University of Auckland 23 Symonds St Auckland 1010 New Zealand
| | - Renjie Huang
- School of Chemical Sciences, The University of Auckland 23 Symonds St Auckland 1010 New Zealand
| | - Ivanhoe K H Leung
- School of Chemical Sciences, The University of Auckland 23 Symonds St Auckland 1010 New Zealand .,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland 1142 New Zealand
| | - Paul W R Harris
- School of Chemical Sciences, The University of Auckland 23 Symonds St Auckland 1010 New Zealand .,School of Biological Sciences, The University of Auckland 3A Symonds St Auckland 1010 New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland 1142 New Zealand
| | - Margaret A Brimble
- School of Chemical Sciences, The University of Auckland 23 Symonds St Auckland 1010 New Zealand .,School of Biological Sciences, The University of Auckland 3A Symonds St Auckland 1010 New Zealand.,Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland 1142 New Zealand
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5
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Hassan MN, Nabi F, Khan AN, Hussain M, Siddiqui WA, Uversky VN, Khan RH. The amyloid state of proteins: A boon or bane? Int J Biol Macromol 2022; 200:593-617. [PMID: 35074333 DOI: 10.1016/j.ijbiomac.2022.01.115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 11/05/2022]
Abstract
Proteins and their aggregation is significant field of research due to their association with various conformational maladies including well-known neurodegenerative diseases like Alzheimer's (AD), Parkinson's (PD), and Huntington's (HD) diseases. Amyloids despite being given negative role for decades are also believed to play a functional role in bacteria to humans. In this review, we discuss both facets of amyloid. We have shed light on AD, which is one of the most common age-related neurodegenerative disease caused by accumulation of Aβ fibrils as extracellular senile plagues. We also discuss PD caused by the aggregation and deposition of α-synuclein in form of Lewy bodies and neurites. Other amyloid-associated diseases such as HD and amyotrophic lateral sclerosis (ALS) are also discussed. We have also reviewed functional amyloids that have various biological roles in both prokaryotes and eukaryotes that includes formation of biofilm and cell attachment in bacteria to hormone storage in humans, We discuss in detail the role of Curli fibrils' in biofilm formation, chaplins in cell attachment to peptide hormones, and Pre-Melansomal Protein (PMEL) roles. The disease-related and functional amyloids are compared with regard to their structural integrity, variation in regulation, and speed of forming aggregates and elucidate how amyloids have turned from foe to friend.
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Affiliation(s)
- Md Nadir Hassan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Faisal Nabi
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Asra Nasir Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Murtaza Hussain
- Department of Biochemistry, Aligarh Muslim University, Aligarh 202002, India
| | - Waseem A Siddiqui
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Vladimir N Uversky
- Protein Research Group, Institute for Biological Instrumentation of the Russian Academy of Sciences, 10 Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy 11 of Sciences", Pushchino, Moscow Region 142290, Russia; Department of Molecular Medicine, USF Health Byrd Alzheimer's Research Institute, Morsani College 13 of Medicine, University of South Florida, Tampa, FL 33612, United States
| | - Rizwan Hasan Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India.
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6
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Slominski RM, Sarna T, Płonka PM, Raman C, Brożyna AA, Slominski AT. Melanoma, Melanin, and Melanogenesis: The Yin and Yang Relationship. Front Oncol 2022; 12:842496. [PMID: 35359389 PMCID: PMC8963986 DOI: 10.3389/fonc.2022.842496] [Citation(s) in RCA: 112] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 01/24/2022] [Indexed: 12/22/2022] Open
Abstract
Melanin pigment plays a critical role in the protection against the harmful effects of ultraviolet radiation and other environmental stressors. It is produced by the enzymatic transformation of L-tyrosine to dopaquinone and subsequent chemical and biochemical reactions resulting in the formation of various 5,6-dihydroxyindole-2-carboxylic acid (DHICA) and 5,6-dihydroxyindole (DHI) oligomers-main constituents of eumelanin, and benzothiazine and benzothiazole units of pheomelanin. The biosynthesis of melanin is regulated by sun exposure and by many hormonal factors at the tissue, cellular, and subcellular levels. While the presence of melanin protects against the development of skin cancers including cutaneous melanoma, its presence may be necessary for the malignant transformation of melanocytes. This shows a complex role of melanogenesis in melanoma development defined by chemical properties of melanin and the nature of generating pathways such as eu- and pheomelanogenesis. While eumelanin is believed to provide radioprotection and photoprotection by acting as an efficient antioxidant and sunscreen, pheomelanin, being less photostable, can generate mutagenic environment after exposure to the short-wavelength UVR. Melanogenesis by itself and its highly reactive intermediates show cytotoxic, genotoxic, and mutagenic activities, and it can stimulate glycolysis and hypoxia-inducible factor 1-alpha (HIF-1α) activation, which, combined with their immunosuppressive effects, can lead to melanoma progression and resistance to immunotherapy. On the other hand, melanogenesis-related proteins can be a target for immunotherapy. Interestingly, clinicopathological analyses on advanced melanomas have shown a negative correlation between tumor pigmentation and diseases outcome as defined by overall survival and disease-free time. This indicates a "Yin and Yang" role for melanin and active melanogenesis in melanoma development, progression, and therapy. Furthermore, based on the clinical, experimental data and diverse effects of melanogenesis, we propose that inhibition of melanogenesis in advanced melanotic melanoma represents a realistic adjuvant strategy to enhance immuno-, radio-, and chemotherapy.
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Affiliation(s)
- Radomir M Slominski
- Graduate Biomedical Sciences Program, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Tadeusz Sarna
- Department of Biophysics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Przemysław M Płonka
- Department of Biophysics and Cancer Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Chander Raman
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Anna A Brożyna
- Department of Human Biology, Institute of Biology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Toruń, Poland
| | - Andrzej T Slominski
- Department of Dermatology, University of Alabama at Birmingham, Birmingham, AL, United States.,Pathology Laboratory Service, Veteran Administration Medical Center at Birmingham, Birmingham, AL, United States
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7
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Bian C, Li R, Wen Z, Ge W, Shi Q. Phylogenetic Analysis of Core Melanin Synthesis Genes Provides Novel Insights Into the Molecular Basis of Albinism in Fish. Front Genet 2021; 12:707228. [PMID: 34422008 PMCID: PMC8371935 DOI: 10.3389/fgene.2021.707228] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Accepted: 07/12/2021] [Indexed: 11/16/2022] Open
Abstract
Melanin is the most prevalent pigment in animals. Its synthesis involves a series of functional genes. Particularly, teleosts have more copies of these genes related to the melanin synthesis than tetrapods. Despite the increasing number of available vertebrate genomes, a few systematically genomic studies were reported to identify and compare these core genes for the melanin synthesis. Here, we performed a comparative genomic analysis on several core genes, including tyrosinase genes (tyr, tyrp1, and tyrp2), premelanosome protein (pmel), microphthalmia-associated transcription factor (mitf), and solute carrier family 24 member 5 (slc24a5), based on 90 representative vertebrate genomes. Gene number and mutation identification suggest that loss-of-function mutations in these core genes may interact to generate an albinism phenotype. We found nonsense mutations in tyrp1a and pmelb of an albino golden-line barbel fish, in pmelb of an albino deep-sea snailfish (Pseudoliparis swirei), in slc24a5 of cave-restricted Mexican tetra (Astyanax mexicanus, cavefish population), and in mitf of a transparent icefish (Protosalanx hyalocranius). Convergent evolution may explain this phenomenon since nonsense mutations in these core genes for melanin synthesis have been identified across diverse albino fishes. These newly identified nonsense mutations and gene loss will provide molecular guidance for ornamental fish breeding, further enhancing our in-depth understanding of human skin coloration.
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Affiliation(s)
- Chao Bian
- Faculty of Health Sciences, Centre of Reproduction, Development and Aging, University of Macau, Taipa, China.,Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, Beijing Genomics Institute, BGI Academy of Marine Sciences, BGI Marine, Shenzhen, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Ruihan Li
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, Beijing Genomics Institute, BGI Academy of Marine Sciences, BGI Marine, Shenzhen, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Zhengyong Wen
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, Beijing Genomics Institute, BGI Academy of Marine Sciences, BGI Marine, Shenzhen, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
| | - Wei Ge
- Faculty of Health Sciences, Centre of Reproduction, Development and Aging, University of Macau, Taipa, China
| | - Qiong Shi
- Shenzhen Key Lab of Marine Genomics, Guangdong Provincial Key Lab of Molecular Breeding in Marine Economic Animals, Beijing Genomics Institute, BGI Academy of Marine Sciences, BGI Marine, Shenzhen, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, China
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8
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Identification of critical amino acid residues in the regulatory N-terminal domain of PMEL. Sci Rep 2021; 11:7730. [PMID: 33833328 PMCID: PMC8032716 DOI: 10.1038/s41598-021-87259-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 03/26/2021] [Indexed: 01/22/2023] Open
Abstract
The pigment cell-specific protein PMEL forms a functional amyloid matrix in melanosomes onto which the pigment melanin is deposited. The amyloid core consists of a short proteolytic fragment, which we have termed the core-amyloid fragment (CAF) and perhaps additional parts of the protein, such as the PKD domain. A highly O-glycosylated repeat (RPT) domain also derived from PMEL proteolysis associates with the amyloid and is necessary to establish the sheet-like morphology of the assemblies. Excluded from the aggregate is the regulatory N-terminus, which nevertheless must be linked in cis to the CAF in order to drive amyloid formation. The domain is then likely cleaved away immediately before, during, or immediately after the incorporation of a new CAF subunit into the nascent amyloid. We had previously identified a 21 amino acid long region, which mediates the regulatory activity of the N-terminus towards the CAF. However, many mutations in the respective segment caused misfolding and/or blocked PMEL export from the endoplasmic reticulum, leaving their phenotype hard to interpret. Here, we employ a saturating mutagenesis approach targeting the motif at single amino acid resolution. Our results confirm the critical nature of the PMEL N-terminal region and identify several residues essential for PMEL amyloidogenesis.
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9
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The Anti-Melanogenesis Effect of 3,4-Dihydroxybenzalacetone through Downregulation of Melanosome Maturation and Transportation in B16F10 and Human Epidermal Melanocytes. Int J Mol Sci 2021; 22:ijms22062823. [PMID: 33802228 PMCID: PMC7999661 DOI: 10.3390/ijms22062823] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 02/27/2021] [Accepted: 03/05/2021] [Indexed: 12/11/2022] Open
Abstract
The biosynthesis pathway of melanin is a series of oxidative reactions that are catalyzed by melanin-related proteins, including tyrosinase (TYR), tyrosinase-related protein-1 (TRP-1), and tyrosinase-related protein-2 (TRP-2). Reagents or materials with antioxidative or free radical-scavenging activities may be candidates for anti-melanogenesis. 3,4-Dihydroxybenzalacetone (DBL) is a polyphenol isolated from fungi, such as Phellinus obliguus (Persoon) Pilat and P. linteus. In this study, we investigated the effects and mechanisms of DBL on antioxidation and melanogenesis in murine melanoma cells (B16F10) and human epidermal melanocytes (HEMs). The results indicated that DBL scavenged 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydroxyl radicals, and exhibited potent reducing power, indicating that it displays strong antioxidative activity. DBL also inhibited the expression of TYR, TRP-1, TRP-2, and microphthalmia-related transcription factor (MITF) in both the cells. In addition, DBL inhibited hyperpigmentation in B16F10 and HEMs by regulating the cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA), v-akt murine thymoma viral oncogene homolog (AKT)/glycogen synthase kinase 3 beta (GSK3β), and mitogen-activated protein kinase kinase (MEK)/extracellular regulated protein kinase (ERK) signaling pathways. DBL not only shortened dendritic melanocytes but also inhibited premelanosome protein 17 (PMEL17) expression, slowing down the maturation of melanosome transportation. These results indicated that DBL promotes anti-melanogenesis by inhibiting the transportation of melanosomes. Therefore, DBL is a potent antioxidant and depigmenting agent that may be used in whitening cosmetics.
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Nijhawan S, Bhargava P, Singdia H, Garg R, Chepa N, Mathur D. The amyloid–melanin connection: a cross sectional study on primary cutaneous Macular Amyloidosis. PIGMENT INTERNATIONAL 2021. [DOI: 10.4103/pigmentinternational.pigmentinternational_36_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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11
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Rahmani Eliato T, Smith JT, Tian Z, Kim ES, Hwang W, Andam CP, Kim YJ. Melanin pigments extracted from horsehair as antibacterial agents. J Mater Chem B 2020; 9:1536-1545. [PMID: 33320923 DOI: 10.1039/d0tb02475a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Here we present the important findings related to biologically derived pigments for potential use as antibacterial agents. Melanin biopigments extracted from Equus ferus hair exhibit a homogeneous elliptical microstructure with highly ordered semicrystalline features. Spectroscopic analysis indicates that melanin contains a high degree of redox active catechol groups, which can produce reactive oxygen species. The antibacterial activity of melanins was tested by incubating Escherichia coli and Staphylococcus aureus with melanins. The results showed 100% bacterial growth inhibition within 4 h. This finding suggests that melanin pigments may serve as naturally occurring antibacterial agents with unique redox chemistry and reactive oxygen species generation capability.
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Affiliation(s)
| | - Joshua T Smith
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA
| | - Zhen Tian
- Department of Chemical Engineering, University of New Hampshire, Durham, NH 03824, USA.
| | - Eun-Sik Kim
- Department of Environmental System Engineering, Chonnam National University, Yeosu, 59626, Republic of Korea
| | - Wonseok Hwang
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20740, USA
| | - Cheryl P Andam
- Department of Molecular, Cellular and Biomedical Sciences, University of New Hampshire, Durham, NH 03824, USA and Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Young Jo Kim
- Department of Chemical Engineering, University of New Hampshire, Durham, NH 03824, USA.
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Reiner G, Weber T, Nietfeld F, Fischer D, Wurmser C, Fries R, Willems H. A genome-wide scan study identifies a single nucleotide substitution in MC1R gene associated with white coat colour in fallow deer (Dama dama). BMC Genet 2020; 21:126. [PMID: 33213385 PMCID: PMC7678172 DOI: 10.1186/s12863-020-00950-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 11/10/2020] [Indexed: 11/10/2022] Open
Abstract
Background The coat colour of fallow deer is highly variable and even white animals can regularly be observed in game farming and in the wild. Affected animals do not show complete albinism but rather some residual pigmentation resembling a very pale beige dilution of coat colour. The eyes and claws of the animals are pigmented. To facilitate the conservation and management of such animals, it would be helpful to know the responsible gene and causative variant. We collected 102 samples from 22 white animals and from 80 animals with wildtype coat colour. The samples came from 12 different wild flocks or game conservations located in different regions of Germany, at the border to Luxembourg and in Poland. The genomes of one white hind and her brown calf were sequenced. Results Based on a list of colour genes of the International Federation of Pigment Cell Societies (http://www.ifpcs.org/albinism/), a variant in the MC1R gene (NM_174108.2:c.143 T > C) resulting in an amino acid exchange from leucine to proline at position 48 of the MC1R receptor protein (NP_776533.1:p.L48P) was identified as a likely cause of coat colour dilution. A gene test revealed that all animals of the white phenotype were of genotype CC whereas all pigmented animals were of genotype TT or TC. The study showed that 14% of the pigmented (brown or dark pigmented) animals carried the white allele. Conclusions A genome-wide scan study led to a molecular test to determine the coat colour of fallow deer. Identification of the MC1R gene provides a deeper insight into the mechanism of dilution. The gene marker is now available for the conservation of white fallow deer in wild and farmed animals. Supplementary Information The online version contains supplementary material available at 10.1186/s12863-020-00950-3.
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Affiliation(s)
- Gerald Reiner
- Department for Veterinary Clinical Science, Justus-Liebig-University, Frankfurter Strasse 112, D-35392, Giessen, Germany. .,Arbeitskreis Wildbiologie e.V., Justus-Liebig-University, Giessen, Germany.
| | - Tim Weber
- Department for Veterinary Clinical Science, Justus-Liebig-University, Frankfurter Strasse 112, D-35392, Giessen, Germany
| | - Florian Nietfeld
- Department for Veterinary Clinical Science, Justus-Liebig-University, Frankfurter Strasse 112, D-35392, Giessen, Germany
| | - Dominik Fischer
- Arbeitskreis Wildbiologie e.V., Justus-Liebig-University, Giessen, Germany
| | - Christine Wurmser
- Department of Animal Breeding, Technical University of Munich, Liesel-Beckmann-Strasse 1, D-85354, Freising-Weihenstephan, Germany
| | - Ruedi Fries
- Department of Animal Breeding, Technical University of Munich, Liesel-Beckmann-Strasse 1, D-85354, Freising-Weihenstephan, Germany
| | - Hermann Willems
- Department for Veterinary Clinical Science, Justus-Liebig-University, Frankfurter Strasse 112, D-35392, Giessen, Germany
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13
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Liang Y, Gerwin J, Meyer A, Kratochwil CF. Developmental and Cellular Basis of Vertical Bar Color Patterns in the East African Cichlid Fish Haplochromis latifasciatus. Front Cell Dev Biol 2020; 8:62. [PMID: 32117987 PMCID: PMC7026194 DOI: 10.3389/fcell.2020.00062] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2019] [Accepted: 01/22/2020] [Indexed: 12/13/2022] Open
Abstract
The East African adaptive radiations of cichlid fishes are renowned for their diversity in coloration. Yet, the developmental basis of pigment pattern formation remains largely unknown. One of the most common melanic patterns in cichlid fishes are vertical bar patterns. Here we describe the ontogeny of this conspicuous pattern in the Lake Kyoga species Haplochromis latifasciatus. Beginning with the larval stages we tracked the formation of this stereotypic color pattern and discovered that its macroscopic appearance is largely explained by an increase in melanophore density and accumulation of melanin during the first 3 weeks post-fertilization. The embryonal analysis is complemented with cytological quantifications of pigment cells in adult scales and the dermis beneath the scales. In adults, melanic bars are characterized by a two to threefold higher density of melanophores than in the intervening yellow interbars. We found no strong support for differences in other pigment cell types such as xanthophores. Quantitative PCRs for twelve known pigmentation genes showed that expression of melanin synthesis genes tyr and tyrp1a is increased five to sixfold in melanic bars, while xanthophore and iridophore marker genes are not differentially expressed. In summary, we provide novel insights on how vertical bars, one of the most widespread vertebrate color patterns, are formed through dynamic control of melanophore density, melanin synthesis and melanosome dispersal.
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Affiliation(s)
- Yipeng Liang
- Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Jan Gerwin
- Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Axel Meyer
- Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Claudius F Kratochwil
- Zoology and Evolutionary Biology, Department of Biology, University of Konstanz, Konstanz, Germany
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14
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A genome-wide scan study identifies a single nucleotide substitution in the tyrosinase gene associated with white coat colour in a red deer (Cervus elaphus) population. BMC Genet 2020; 21:14. [PMID: 32041521 PMCID: PMC7011275 DOI: 10.1186/s12863-020-0814-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 01/20/2020] [Indexed: 12/19/2022] Open
Abstract
Background Red deer with very pale coat colour are observed sporadically. In the red deer (Cervus elaphus) population of Reinhardswald in Germany, about 5% of animals have a white coat colour that is not associated with albinism. In order to facilitate the conservation of the animals, it should be determined whether and to what extent brown animals carry the white gene. For this purpose, samples of one white hind and her brown calf were available for whole genome sequencing to identify the single nucleotide polymorphism(s) responsible for the white phenotype. Subsequently, samples from 194 brown and 11 white animals were genotyped. Results Based on a list of colour genes of the International Federation of Pigment Cell Societies, a non-synonymous mutation with exchange of a glycine residue at position 291 of the tyrosinase protein by arginine was identified as the cause of dilution of the coat colour. A gene test led to exactly matching genotypes in all examined animals. The study showed that 14% of the brown animals carry the white gene. This provides a simple and reliable way of conservation for the white animals. However, results could not be transferred to another, unrelated red deer population with white animals. Although no brown animals with a white tyrosinase genotype were detected, the cause for the white colouring in this population was different. Conclusions A gene test for the conservation of white red deer is available for the population of the Reinhardswald. While mutations in the tyrosinase are commonly associated with oculocutaneous albinism type 1, the amino acid exchange at position 291 was found to be associated with coat colour dilution in Cervus elaphus.
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15
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Avni A, Swasthi HM, Majumdar A, Mukhopadhyay S. Intrinsically disordered proteins in the formation of functional amyloids from bacteria to humans. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2019; 166:109-143. [PMID: 31521230 DOI: 10.1016/bs.pmbts.2019.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Amyloids are nanoscopic ordered self-assemblies of misfolded proteins that are formed via aggregation of partially unfolded or intrinsically disordered proteins (IDPs) and are commonly linked to devastating human diseases. An enlarging body of recent research has demonstrated that certain amyloids can be beneficial and participate in a wide range of physiological functions from bacteria to humans. These amyloids are termed as functional amyloids. Like disease-associated amyloids, a vast majority of functional amyloids are derived from a range of IDPs or hybrid proteins containing ordered domains and intrinsically disordered regions (IDRs). In this chapter, we describe an account of recent studies on the aggregation behavior of IDPs resulting in the formation of functional amyloids in a diverse range of organisms from bacteria to human. We also discuss the strategies that are used by these organisms to regulate the spatiotemporal amyloid assembly in their physiological functions.
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Affiliation(s)
- Anamika Avni
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, and Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India
| | - Hema M Swasthi
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, and Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India
| | - Anupa Majumdar
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, and Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India
| | - Samrat Mukhopadhyay
- Centre for Protein Science, Design and Engineering, Department of Biological Sciences, and Department of Chemical Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Punjab, India.
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16
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Lahola-Chomiak AA, Footz T, Nguyen-Phuoc K, Neil GJ, Fan B, Allen KF, Greenfield DS, Parrish RK, Linkroum K, Pasquale LR, Leonhardt RM, Ritch R, Javadiyan S, Craig JE, Allison WT, Lehmann OJ, Walter MA, Wiggs JL. Non-Synonymous variants in premelanosome protein (PMEL) cause ocular pigment dispersion and pigmentary glaucoma. Hum Mol Genet 2019; 28:1298-1311. [PMID: 30561643 DOI: 10.1093/hmg/ddy429] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 12/04/2018] [Accepted: 12/12/2018] [Indexed: 01/25/2023] Open
Abstract
Pigmentary glaucoma (PG) is a common glaucoma subtype that results from release of pigment from the iris, called pigment dispersion syndrome (PDS), and its deposition throughout the anterior chamber of the eye. Although PG has a substantial heritable component, no causative genes have yet been identified. We used whole exome sequencing of two independent pedigrees to identify two premelanosome protein (PMEL) variants associated with heritable PDS/PG. PMEL encodes a key component of the melanosome, the organelle essential for melanin synthesis, storage and transport. Targeted screening of PMEL in three independent cohorts (n = 394) identified seven additional PDS/PG-associated non-synonymous variants. Five of the nine variants exhibited defective processing of the PMEL protein. In addition, analysis of PDS/PG-associated PMEL variants expressed in HeLa cells revealed structural changes to pseudomelanosomes indicating altered amyloid fibril formation in five of the nine variants. Introduction of 11-base pair deletions to the homologous pmela in zebrafish by the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 method caused profound pigmentation defects and enlarged anterior segments in the eye, further supporting PMEL's role in ocular pigmentation and function. Taken together, these data support a model in which missense PMEL variants represent dominant negative mutations that impair the ability of PMEL to form functional amyloid fibrils. While PMEL mutations have previously been shown to cause pigmentation and ocular defects in animals, this research is the first report of mutations in PMEL causing human disease.
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Affiliation(s)
| | - Tim Footz
- Department of Medical Genetics, University of Alberta, Edmonton AB, Canada
| | - Kim Nguyen-Phuoc
- Department of Medical Genetics, University of Alberta, Edmonton AB, Canada
| | - Gavin J Neil
- Department of Biological Sciences, University of Alberta, Edmonton AB, Canada
| | - Baojian Fan
- Ocular Genomics Institute and Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Keri F Allen
- Ocular Genomics Institute and Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - David S Greenfield
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Palm Beach Gardens, FL, USA
| | - Richard K Parrish
- Anne Bates Leach Eye Hospital, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Kevin Linkroum
- Ocular Genomics Institute and Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Louis R Pasquale
- Ocular Genomics Institute and Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Ralf M Leonhardt
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | - Robert Ritch
- Einhorn Clinical Research Center, New York Eye and Ear Infirmary of Mount Sinai, New York, NY, USA
| | - Shari Javadiyan
- Department of Ophthalmology, Flinders Medical Centre, Adelaide, South Australia, Australia
| | - Jamie E Craig
- Department of Ophthalmology, Flinders Medical Centre, Adelaide, South Australia, Australia
| | - W T Allison
- Department of Medical Genetics, University of Alberta, Edmonton AB, Canada.,Department of Biological Sciences, University of Alberta, Edmonton AB, Canada
| | - Ordan J Lehmann
- Department of Medical Genetics, University of Alberta, Edmonton AB, Canada.,Department of Ophthalmology, University of Alberta, Edmonton AB, Canada
| | - Michael A Walter
- Department of Medical Genetics, University of Alberta, Edmonton AB, Canada
| | - Janey L Wiggs
- Ocular Genomics Institute and Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
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17
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Mondal S, Thampi A, Puranik M. Kinetics of Melanin Polymerization during Enzymatic and Nonenzymatic Oxidation. J Phys Chem B 2018; 122:2047-2063. [PMID: 29364665 DOI: 10.1021/acs.jpcb.7b07941] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Melanin is an abundant biopigment in the animal kingdom, but its structure remains poorly understood. This is a substantial impediment to understanding the mechanistic origin of its observed functions. Proposed models of melanin structure include aggregates of both linear and macrocyclic units and noncovalently held monomers. Both models are broadly in agreement with current experimental data. To constrain the structural and kinetic models of melanin, experimental data of high resolution with chemical specificity accompanied by atomistic modeling are required. We have addressed this by obtaining electronic absorption, infrared, and ultraviolet resonance Raman (RR) spectra of melanin at several wavelengths of excitation that are sensitive to small changes in structure. From these experiments, we observed kinetics of the formation of different species en route to melanin polymerization. Exclusive chemical signatures of monomer 3,4-dihydroxyphenylalanine (dopa), intermediate dopachrome (DC), and early-time polymer are established through their vibrational bands at 1292, 1670, and 1616 cm-1 respectively. Direct evidence of reduced heterogeneity of melanin oligomers in tyrosinase-induced formation is provided from experimental measurements of vibrational bandwidths. Models made with density functional theory show that the linear homopolymeric structures of 5,6-dihydroxyindole can account for experimentally observed wavenumbers and broad bandwidth in Raman spectra of dopa-melanin. We capture resonance Raman (RR) signature of DC, the intermediate stabilized by the enzyme tyrosinase, for the first time in an enzyme-assisted melanization reaction using 488 nm excitation wavelength and propose that this wavelength can be used to probe reaction intermediates of melanin formation in solution.
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Affiliation(s)
- Sayan Mondal
- Indian Institute of Science Education and Research , Pune 411008, India
| | - Arya Thampi
- Indian Institute of Science Education and Research , Pune 411008, India
| | - Mrinalini Puranik
- Indian Institute of Science Education and Research , Pune 411008, India
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18
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Park EH, Bae WY, Kim JY, Kim KT, Paik HD. Antimelanogenic effects of Inula britannica flower petal extract fermented by Lactobacillus plantarum KCCM 11613P *. J Zhejiang Univ Sci B 2017; 18:816-824. [PMCID: PMC5611553 DOI: 10.1631/jzus.b1600234] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2016] [Accepted: 10/23/2016] [Indexed: 07/30/2023]
Abstract
The inhibitory effects of Lactobacillus plantarum-fermented and non-fermented Inula britannica extracts on the tyrosinase activity were comparatively investigated to examine whether and how they improve the whitening activity, and the contents of total flavonoids and polyphenolics as bioactive compounds were determined. The skin whitening activity using in vitro or ex vivo tyrosinase and L-3,4-dihydroxyphenylalanine (L-DOPA) staining was examined. The total flavonoid content (TFC) was increased by 13.4% after 72 h-fermentation. The viabilities of the B16F10 cells treated with the fermented and non-fermented control extracts were 100.26% and 92.15% at 500 µg/ml, respectively. In addition, the inhibition of tyrosinase activity was increased by the fermented samples from 29.33% to 41.74% following fermentation for up to 72 h. The tyrosinase activity of the untreated control group was increased to 145.69% in B16F10 cells. The results showed that I. britannica fermented by L. plantarum dose-dependently inhibited tyrosinase activity, which was stimulated by α-melanocyte stimulating hormone. These results suggest that lactic fermented I. britannica extracts can be used as effective skin-whitening materials.
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Affiliation(s)
- Eun-hye Park
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Korea
| | - Won-young Bae
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Korea
| | - Jae-yeon Kim
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Korea
| | - Kee-tae Kim
- Bio/Molecular Informatics Center, Konkuk University, Seoul 05029, Korea
| | - Hyun-dong Paik
- Department of Food Science and Biotechnology of Animal Resources, Konkuk University, Seoul 05029, Korea
- Bio/Molecular Informatics Center, Konkuk University, Seoul 05029, Korea
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19
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Bissig C, Rochin L, van Niel G. PMEL Amyloid Fibril Formation: The Bright Steps of Pigmentation. Int J Mol Sci 2016; 17:ijms17091438. [PMID: 27589732 PMCID: PMC5037717 DOI: 10.3390/ijms17091438] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 08/12/2016] [Accepted: 08/22/2016] [Indexed: 02/06/2023] Open
Abstract
In pigment cells, melanin synthesis takes place in specialized organelles, called melanosomes. The biogenesis and maturation of melanosomes is initiated by an unpigmented step that takes place prior to the initiation of melanin synthesis and leads to the formation of luminal fibrils deriving from the pigment cell-specific pre-melanosomal protein (PMEL). In the lumen of melanosomes, PMEL fibrils optimize sequestration and condensation of the pigment melanin. Interestingly, PMEL fibrils have been described to adopt a typical amyloid-like structure. In contrast to pathological amyloids often associated with neurodegenerative diseases, PMEL fibrils represent an emergent category of physiological amyloids due to their beneficial cellular functions. The formation of PMEL fibrils within melanosomes is tightly regulated by diverse mechanisms, such as PMEL traffic, cleavage and sorting. These mechanisms revealed increasing analogies between the formation of physiological PMEL fibrils and pathological amyloid fibrils. In this review we summarize the known mechanisms of PMEL fibrillation and discuss how the recent understanding of physiological PMEL amyloid formation may help to shed light on processes involved in pathological amyloid formation.
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Affiliation(s)
- Christin Bissig
- Institut Curie, Paris Sciences et Lettres Research University, UMR144, Centre de Recherche, 26 rue d'ULM, Paris F-75231, France.
- Centre National de la Recherche Scientifique, UMR144, Paris F-75248, France.
| | - Leila Rochin
- Department of Cellular and Molecular Physiology, Institute of Translational Medicine, University of Liverpool, Liverpool L69 3BX, UK.
| | - Guillaume van Niel
- Institut Curie, Paris Sciences et Lettres Research University, UMR144, Centre de Recherche, 26 rue d'ULM, Paris F-75231, France.
- Centre National de la Recherche Scientifique, UMR144, Paris F-75248, France.
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20
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Pharmacological BACE1 and BACE2 inhibition induces hair depigmentation by inhibiting PMEL17 processing in mice. Sci Rep 2016; 6:21917. [PMID: 26912421 PMCID: PMC4766495 DOI: 10.1038/srep21917] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 02/02/2016] [Indexed: 02/04/2023] Open
Abstract
Melanocytes of the hair follicle produce melanin and are essential in determining the differences in hair color. Pigment cell-specific MELanocyte Protein (PMEL17) plays a crucial role in melanogenesis. One of the critical steps is the amyloid-like functional oligomerization of PMEL17. Beta Site APP Cleaving Enzyme-2 (BACE2) and γ-secretase have been shown to be key players in generating the proteolytic fragments of PMEL17. The β-secretase (BACE1) is responsible for the generation of amyloid-β (Aβ) fragments in the brain and is therefore proposed as a therapeutic target for Alzheimer's disease (AD). Currently BACE1 inhibitors, most of which lack selectivity over BACE2, have demonstrated efficacious reduction of amyloid-β peptides in animals and the CSF of humans. BACE2 knock-out mice have a deficiency in PMEL17 proteolytic processing leading to impaired melanin storage and hair depigmentation. Here, we confirm BACE2-mediated inhibition of PMEL17 proteolytic processing in vitro in mouse and human melanocytes. Furthermore, we show that wildtype as well as bace2(+/-) and bace2(-/-) mice treated with a potent dual BACE1/BACE2 inhibitor NB-360 display dose-dependent appearance of irreversibly depigmented hair. Retinal pigmented epithelium showed no morphological changes. Our data demonstrates that BACE2 as well as additional BACE1 inhibition affects melanosome maturation and induces hair depigmentation in mice.
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21
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Ho T, Watt B, Spruce LA, Seeholzer SH, Marks MS. The Kringle-like Domain Facilitates Post-endoplasmic Reticulum Changes to Premelanosome Protein (PMEL) Oligomerization and Disulfide Bond Configuration and Promotes Amyloid Formation. J Biol Chem 2015; 291:3595-612. [PMID: 26694611 DOI: 10.1074/jbc.m115.692442] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Indexed: 11/06/2022] Open
Abstract
The formation of functional amyloid must be carefully regulated to prevent the accumulation of potentially toxic products. Premelanosome protein (PMEL) forms non-toxic functional amyloid fibrils that assemble into sheets upon which melanins ultimately are deposited within the melanosomes of pigment cells. PMEL is synthesized in the endoplasmic reticulum but forms amyloid only within post-Golgi melanosome precursors; thus, PMEL must traverse the secretory pathway in a non-amyloid form. Here, we identified two pre-amyloid PMEL intermediates that likely regulate the timing of fibril formation. Analyses by non-reducing SDS-PAGE, size exclusion chromatography, and sedimentation velocity revealed two native high Mr disulfide-bonded species that contain Golgi-modified forms of PMEL. These species correspond to disulfide bond-containing dimeric and monomeric PMEL isoforms that contain no other proteins as judged by two-dimensional PAGE of metabolically labeled/immunoprecipitated PMEL and by mass spectrometry of affinity-purified complexes. Metabolic pulse-chase analyses, small molecule inhibitor treatments, and evaluation of site-directed mutants suggest that the PMEL dimer forms around the time of endoplasmic reticulum exit and is resolved by disulfide bond rearrangement into a monomeric form within the late Golgi or a post-Golgi compartment. Mutagenesis of individual cysteine residues within the non-amyloid cysteine-rich Kringle-like domain stabilizes the disulfide-bonded dimer and impairs fibril formation as determined by electron microscopy. Our data show that the Kringle-like domain facilitates the resolution of disulfide-bonded PMEL dimers and promotes PMEL functional amyloid formation, thereby suggesting that PMEL dimers must be resolved to monomers to generate functional amyloid fibrils.
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Affiliation(s)
- Tina Ho
- From the Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 and the Cell and Molecular Biology Graduate Group, the Department of Pathology and Laboratory Medicine, and
| | - Brenda Watt
- From the Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 and the Cell and Molecular Biology Graduate Group, the Department of Pathology and Laboratory Medicine, and
| | - Lynn A Spruce
- From the Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 and
| | - Steven H Seeholzer
- From the Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 and
| | - Michael S Marks
- From the Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104 and the Cell and Molecular Biology Graduate Group, the Department of Pathology and Laboratory Medicine, and the Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104
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22
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Klosterman L, Riley JK, Bettinger CJ. Control of heterogeneous nucleation and growth kinetics of dopamine-melanin by altering substrate chemistry. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3451-3458. [PMID: 25741573 DOI: 10.1021/acs.langmuir.5b00105] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Dopamine-melanin (DM or "polydopamine") can be deposited on virtually any substrate from solution through autoxidation of dopamine. The versatility of this process has allowed surface-mediated assembly of DM for a wide variety of functional coatings. Here we report the impact of well-defined surface chemistries on the nucleation and growth of such films. DM was deposited on silicon dioxide (SiO2) and SiO2 substrates modified with self-assembled monolayers (SAMs) bearing octadecyl (C18), phenethyl, and aminopropyl functional groups. Atomic force microscopy revealed three-dimensional islands whose areal density and surface coverage are lowest on bare SiO2 substrates and highest on the neutral aromatic and aliphatic substrates. Increasing the pH of the solution from 8.2 to 10 dissociates catechol moieties in DM and inhibits adsorption on negatively charged SiO2 substrates. The growth rate of DM films on SAM-modified SiO2 is maximized at pH 9.5 and almost completely abolished at pH 10 because of increased DM solubility. The initial rates of DM adsorption were measured using quartz crystal microbalance with dissipation measurements. The initial adsorption rate is proportional to the nucleation density, which increases as the hydrophobicity of the substrate increases. Taken together, these data provide insight into the rates of heterogeneous nucleation and growth of DM on substrates with well-defined chemistries.
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Affiliation(s)
- Luke Klosterman
- †Department of Materials Science and Engineering, ‡Department of Chemical Engineering, and §Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - John K Riley
- †Department of Materials Science and Engineering, ‡Department of Chemical Engineering, and §Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Christopher John Bettinger
- †Department of Materials Science and Engineering, ‡Department of Chemical Engineering, and §Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
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23
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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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Comparative transcriptome analysis reveals the genetic basis of skin color variation in common carp. PLoS One 2014; 9:e108200. [PMID: 25255374 PMCID: PMC4177847 DOI: 10.1371/journal.pone.0108200] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2014] [Accepted: 08/18/2014] [Indexed: 01/03/2023] Open
Abstract
Background The common carp is an important aquaculture species that is widely distributed across the world. During the long history of carp domestication, numerous carp strains with diverse skin colors have been established. Skin color is used as a visual criterion to determine the market value of carp. However, the genetic basis of common carp skin color has not been extensively studied. Methodology/Principal Findings In this study, we performed Illumina sequencing on two common carp strains: the reddish Xingguo red carp and the brownish-black Yellow River carp. A total of 435,348,868 reads were generated, resulting in 198,781 assembled contigs that were used as reference sequences. Comparisons of skin transcriptome files revealed 2,012 unigenes with significantly different expression in the two common carp strains, including 874 genes that were up-regulated in Xingguo red carp and 1,138 genes that were up-regulated in Yellow River carp. The expression patterns of 20 randomly selected differentially expressed genes were validated using quantitative RT-PCR. Gene pathway analysis of the differentially expressed genes indicated that melanin biosynthesis, along with the Wnt and MAPK signaling pathways, is highly likely to affect the skin pigmentation process. Several key genes involved in the skin pigmentation process, including TYRP1, SILV, ASIP and xCT, showed significant differences in their expression patterns between the two strains. Conclusions In this study, we conducted a comparative transcriptome analysis of Xingguo red carp and Yellow River carp skins, and we detected key genes involved in the common carp skin pigmentation process. We propose that common carp skin pigmentation depends upon at least three pathways. Understanding fish skin color genetics will facilitate future molecular selection of the fish skin colors with high market values.
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Zbytek B, Peacock DL, Seagroves TN, Slominski A. Putative role of HIF transcriptional activity in melanocytes and melanoma biology. DERMATO-ENDOCRINOLOGY 2014; 5:239-51. [PMID: 24194964 PMCID: PMC3772912 DOI: 10.4161/derm.22678] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Revised: 10/23/2012] [Accepted: 10/26/2012] [Indexed: 12/30/2022]
Abstract
Hypoxia-inducible factor-1α (HIF-1α) is a highly oxygen sensitive bHLH protein that is part of the heterodimeric HIF-1 transcription factor. Under hypoxic stress, HIF-1 activity is induced to control expression of multiple downstream target genes, including vascular endothelial growth factor (VEGF). The normal epidermis exists in a constant mild hypoxic microenvironment and constitutively expresses HIF-1α and HIF-2α. Expression of HIF-1α and/or HIF-2α has been suggested to correlate with the increased malignant potential of melanocytes, therefore, failures of melanoma therapies may be partially linked to high HIF activity. Notably, melanomas that have the V600E BRAF mutation exhibit increased HIF-1α expression. We have utilized a bioinformatics approach to identify putative hypoxia response elements (HREs) in a set of genes known to participate in the process of melanogenesis (includingTRPM1, SLC45A2, HRAS, C-KIT, PMEL and CRH). While some of the mechanistic links between these genes and the HIF pathway have been previously explored, others await further investigation. Although agents targeting HIF activity have been proposed as novel treatment modalities for melanoma, there are currently no clinical trials in progress to test their efficacy in melanoma.
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Affiliation(s)
- Blazej Zbytek
- Department of Pathology and Laboratory Medicine; Center for Adult Cancer Research; University of Tennessee Health Science Center; Memphis, TN USA
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Expression of skin color genes in lymphocytes of Karan Fries cattle and seasonal relationship with tyrosinase and cortisol. Trop Anim Health Prod 2014; 46:1155-60. [PMID: 24891258 DOI: 10.1007/s11250-014-0620-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2014] [Indexed: 12/21/2022]
Abstract
To evaluate difference in the expression of skin color genes (melanocortin 1 receptor (MC1R) and premelanosome (PMEL)) in lymphocytes during winter and summer season and their correlation with tyrosinase enzyme and cortisol, ten Karan-Fries heifers were selected from National Dairy Research Institute (NDRI) cattle farm. Blood samples were collected from the animals during winter (THI = 60) and summer (THI = 83) season at weekly intervals. Relative MC1R and PMEL messenger RNA (mRNA) expression of Karan Fries cattle was found to be significantly (P < 0.01) higher during winter than summer. Similarly, tyrosinase activity during winter was found to be significantly (P < 0.01) higher than summer season. However, plasma cortisol level was significantly (P < 0.01) higher during summer than winter. Thus, expression of the skin color genes showed positive correlation with tyrosinase enzyme, but negative correlation with cortisol level. Expression of MC1R and PMEL in lymphocytes and tyrosinase activity of Karan Fries cattle was highly reduced during summer. The present study showed that the ability of Karan Fries cattle to protect themselves from the harmful radiation of sunlight by melanization decreased with increased heat stress on them.
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Andersson LS, Wilbe M, Viluma A, Cothran G, Ekesten B, Ewart S, Lindgren G. Equine multiple congenital ocular anomalies and silver coat colour result from the pleiotropic effects of mutant PMEL. PLoS One 2013; 8:e75639. [PMID: 24086599 PMCID: PMC3781063 DOI: 10.1371/journal.pone.0075639] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Accepted: 08/18/2013] [Indexed: 11/19/2022] Open
Abstract
Equine Multiple Congenital Ocular Anomalies (MCOA) syndrome is a heritable eye disorder mainly affecting silver colored horses. Clinically, the disease manifests in two distinct classes depending on the horse genotype. Horses homozygous for the mutant allele present with a wide range of ocular defects, such as iris stromal hypoplasia, abnormal pectinate ligaments, megaloglobus, iridociliary cysts and cataracts. The phenotype of heterozygous horses is less severe and predominantly includes iridociliary cysts, which occasionally extend into the temporal retina. In order to determine the genetic cause of MCOA syndrome we sequenced the entire previously characterized 208 kilobase region on chromosome 6 in ten individuals; five MCOA affected horses from three different breeds, one horse with the intermediate Cyst phenotype and four unaffected controls from two different breeds. This was performed using Illumina TruSeq technology with paired-end reads. Through the systematic exclusion of all polymorphisms barring two SNPs in PMEL, a missense mutation previously reported to be associated with the silver coat colour and a non-conserved intronic SNP, we establish that this gene is responsible for MCOA syndrome. Our finding, together with recent advances that show aberrant protein function due to the coding mutation, suggests that the missense mutation is causative and has pleiotrophic effect, causing both the horse silver coat color and MCOA syndrome.
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Affiliation(s)
- Lisa S. Andersson
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Maria Wilbe
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Agnese Viluma
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Gus Cothran
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, United States of America
| | - Björn Ekesten
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Susan Ewart
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
| | - Gabriella Lindgren
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
- * E-mail:
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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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Wu CY, Pang JHS, Huang ST. Inhibition of Melanogenesis in Murine B16/F10 Melanoma Cells byLigusticum sinensis Oliv. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2012; 34:523-33. [PMID: 16710901 DOI: 10.1142/s0192415x06004053] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ligusticum sinensis Oliv. (LSO) is an herbal drug commonly used as a topical treatment of epidermal hyperdepigmentation in Chinese medicine. However, the mechanism underlying the depigmentation by LSO is still unclear. The purpose of this study was to investigate the effects of LSO on the process of melanogenesis and its possible underlying mechanism. Suppressed DOPA oxidase activity of mushroom tyrosinase was first noted when incubated with aqueous extracts of LSO, demonstrating the direct inhibitory effect of LSO on mushroom tyrosinase. Further experiments were carried out in murine B16/F10 melanoma cells and the effects of LSO extract on melanin formation, tyrosinase activity and tyrosinase gene expression were tested. Under conditions without affecting the viability of murine B16/F10 melanoma cells, LSO extract significantly reduced the cellular melanin content in a dose-dependent manner. The DOPA oxidase activity of tyrosinase in B16/F10 cells was dose-dependently inhibited by LSO treatment, possibly mediated by the suppressed tyrosinase mRNA expression in LSO-treated B16/F10 cells. In conclusion, the inhibitory effect of LSO on melanogenesis is likely associated with decreased DOPA oxidase activity of tyrosinase that is most likely the result of the down-regulation of tyrosinase mRNA expression.
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Affiliation(s)
- Ching-Yuan Wu
- Department of Chinese Medicine, Chang Gung Memorial Hospital, Kaohsiung, Taiwan, R.O.C
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Watt B, Tenza D, Lemmon MA, Kerje S, Raposo G, Andersson L, Marks MS. Mutations in or near the transmembrane domain alter PMEL amyloid formation from functional to pathogenic. PLoS Genet 2011; 7:e1002286. [PMID: 21949659 PMCID: PMC3174235 DOI: 10.1371/journal.pgen.1002286] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2011] [Accepted: 07/28/2011] [Indexed: 11/18/2022] Open
Abstract
PMEL is a pigment cell-specific protein that forms physiological amyloid fibrils upon which melanins ultimately deposit in the lumen of the pigment organelle, the melanosome. Whereas hypomorphic PMEL mutations in several species result in a mild pigment dilution that is inherited in a recessive manner, PMEL alleles found in the Dominant white (DW) chicken and Silver horse (HoSi)--which bear mutations that alter the PMEL transmembrane domain (TMD) and that are thus outside the amyloid core--are associated with a striking loss of pigmentation that is inherited in a dominant fashion. Here we show that the DW and HoSi mutations alter PMEL TMD oligomerization and/or association with membranes, with consequent formation of aberrantly packed fibrils. The aberrant fibrils are associated with a loss of pigmentation in cultured melanocytes, suggesting that they inhibit melanin production and/or melanosome integrity. A secondary mutation in the Smoky chicken, which reverts the dominant DW phenotype, prevents the accumulation of PMEL in fibrillogenic compartments and thus averts DW-associated pigment loss; a secondary mutation found in the Dun chicken likely dampens a HoSi-like dominant mutation in a similar manner. We propose that the DW and HoSi mutations alter the normally benign amyloid to a pathogenic form that antagonizes melanosome function, and that the secondary mutations found in the Smoky and Dun chickens revert or dampen pathogenicity by functioning as null alleles, thus preventing the formation of aberrant fibrils. We speculate that PMEL mutations can model the conversion between physiological and pathological amyloid.
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Affiliation(s)
- Brenda Watt
- Department of Pathology and Laboratory Medicine and Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Cell and Molecular Biology Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Danièle Tenza
- Institut Curie, Centre de Recherche, Paris, France
- CNRS, UMR-144, Paris, France
| | - Mark A. Lemmon
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Susanne Kerje
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
| | - Graça Raposo
- Institut Curie, Centre de Recherche, Paris, France
- CNRS, UMR-144, Paris, France
| | - Leif Andersson
- Science for Life Laboratory, Department of Medical Biochemistry and Microbiology, Uppsala University, Uppsala, Sweden
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Michael S. Marks
- Department of Pathology and Laboratory Medicine and Department of Physiology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- Cell and Molecular Biology Graduate Group, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
- * E-mail:
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Inactivation of Pmel alters melanosome shape but has only a subtle effect on visible pigmentation. PLoS Genet 2011; 7:e1002285. [PMID: 21949658 PMCID: PMC3174228 DOI: 10.1371/journal.pgen.1002285] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 06/18/2011] [Indexed: 11/19/2022] Open
Abstract
PMEL is an amyloidogenic protein that appears to be exclusively expressed in pigment cells and forms intralumenal fibrils within early stage melanosomes upon which eumelanins deposit in later stages. PMEL is well conserved among vertebrates, and allelic variants in several species are associated with reduced levels of eumelanin in epidermal tissues. However, in most of these cases it is not clear whether the allelic variants reflect gain-of-function or loss-of-function, and no complete PMEL loss-of-function has been reported in a mammal. Here, we have created a mouse line in which the Pmel gene has been inactivated (Pmel−/−). These mice are fully viable, fertile, and display no obvious developmental defects. Melanosomes within Pmel−/− melanocytes are spherical in contrast to the oblong shape present in wild-type animals. This feature was documented in primary cultures of skin-derived melanocytes as well as in retinal pigment epithelium cells and in uveal melanocytes. Inactivation of Pmel has only a mild effect on the coat color phenotype in four different genetic backgrounds, with the clearest effect in mice also carrying the brown/Tyrp1 mutation. This phenotype, which is similar to that observed with the spontaneous silver mutation in mice, strongly suggests that other previously described alleles in vertebrates with more striking effects on pigmentation are dominant-negative mutations. Despite a mild effect on visible pigmentation, inactivation of Pmel led to a substantial reduction in eumelanin content in hair, which demonstrates that PMEL has a critical role for maintaining efficient epidermal pigmentation. Pigmentation has since long constituted a prime model to study how genes act and interact. The PMEL gene encodes a protein exclusively found in the melanosomes of pigment-producing cells. Mutations in PMEL underlie some spectacular color phenotypes in animals including Dominant white color in chickens, Silver in horses, and Merle in dogs, but no spontaneous mutation causing a complete inactivation of this gene has yet been found in mammals. We have now developed a PMEL knockout mouse to further study the function of this protein. We show that mice lacking PMEL have almost normal visible pigmentation. However, loss of PMEL has a dramatic effect on the morphology of the melanosomes in skin, hair, and eye, such that the normally rod-shaped melanosomes in wild-type animals are spherical in the knockout mice. The knockout animals also have a substantial reduction in the content of black pigment in hair. The study establishes that PMEL has a critical role for maintaining normal pigment production.
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Pleshkan VV, Zinovyeva MV, Sverdlov ED. Melanoma: Surface markers as the first point of targeted delivery of therapeutic genes in multilevel gene therapy. Mol Biol 2011. [DOI: 10.1134/s0026893311030149] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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Watt B, van Niel G, Fowler DM, Hurbain I, Luk KC, Stayrook SE, Lemmon MA, Raposo G, Shorter J, Kelly JW, Marks MS. N-terminal domains elicit formation of functional Pmel17 amyloid fibrils. J Biol Chem 2010; 284:35543-55. [PMID: 19840945 DOI: 10.1074/jbc.m109.047449] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pmel17 is a transmembrane protein that mediates the early steps in the formation of melanosomes, the subcellular organelles of melanocytes in which melanin pigments are synthesized and stored. In melanosome precursor organelles, proteolytic fragments of Pmel17 form insoluble, amyloid-like fibrils upon which melanins are deposited during melanosome maturation. The mechanism(s) by which Pmel17 becomes competent to form amyloid are not fully understood. To better understand how amyloid formation is regulated, we have defined the domains within Pmel17 that promote fibril formation in vitro. Using purified recombinant fragments of Pmel17, we show that two regions, an N-terminal domain of unknown structure and a downstream domain with homology to a polycystic kidney disease-1 repeat, efficiently form amyloid in vitro. Analyses of fibrils formed in melanocytes confirm that the polycystic kidney disease-1 domain forms at least part of the physiological amyloid core. Interestingly, this same domain is also required for the intracellular trafficking of Pmel17 to multivesicular compartments within which fibrils begin to form. Although a domain of imperfect repeats (RPT) is required for fibril formation in vivo and is a component of fibrils in melanosomes, RPT is not necessary for fibril formation in vitro and in isolation is unable to adopt an amyloid fold in a physiologically relevant time frame. These data define the structural core of Pmel17 amyloid, imply that the RPT domain plays a regulatory role in timing amyloid conversion, and suggest that fibril formation might be physically linked with multivesicular body sorting.
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Affiliation(s)
- Brenda Watt
- Departments of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Levin MD, Lu MM, Petrenko NB, Hawkins BJ, Gupta TH, Lang D, Buckley PT, Jochems J, Liu F, Spurney CF, Yuan LJ, Jacobson JT, Brown CB, Huang L, Beermann F, Margulies KB, Madesh M, Eberwine JH, Epstein JA, Patel VV. Melanocyte-like cells in the heart and pulmonary veins contribute to atrial arrhythmia triggers. J Clin Invest 2009; 119:3420-36. [PMID: 19855129 DOI: 10.1172/jci39109] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2009] [Accepted: 08/25/2009] [Indexed: 01/27/2023] Open
Abstract
Atrial fibrillation is the most common clinical cardiac arrhythmia. It is often initiated by ectopic beats arising from the pulmonary veins and atrium, but the source and mechanism of these beats remains unclear. The melanin synthesis enzyme dopachrome tautomerase (DCT) is involved in intracellular calcium and reactive species regulation in melanocytes. Given that dysregulation of intracellular calcium and reactive species has been described in patients with atrial fibrillation, we investigated the role of DCT in this process. Here, we characterize a unique DCT-expressing cell population within murine and human hearts that populated the pulmonary veins, atria, and atrioventricular canal. Expression profiling demonstrated that this population expressed adrenergic and muscarinic receptors and displayed transcriptional profiles distinct from dermal melanocytes. Adult mice lacking DCT displayed normal cardiac development but an increased susceptibility to atrial arrhythmias. Cultured primary cardiac melanocyte-like cells were excitable, and those lacking DCT displayed prolonged repolarization with early afterdepolarizations. Furthermore, mice with mutations in the tyrosine kinase receptor Kit lacked cardiac melanocyte-like cells and did not develop atrial arrhythmias in the absence of DCT. These data suggest that dysfunction of melanocyte-like cells in the atrium and pulmonary veins may contribute to atrial arrhythmias.
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Affiliation(s)
- Mark D Levin
- Penn Cardiovascular Institute and University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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A mutation within the transmembrane domain of melanosomal protein Silver (Pmel17) changes lumenal fragment interactions. Eur J Cell Biol 2009; 88:653-67. [PMID: 19679373 DOI: 10.1016/j.ejcb.2009.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2009] [Revised: 07/05/2009] [Accepted: 07/05/2009] [Indexed: 11/23/2022] Open
Abstract
Melanocytes synthesize and store melanin within tissue-specific organelles, the melanosomes. Melanin deposition takes place along fibrils found within these organelles and fibril formation is known to depend on trafficking of the membrane glycoprotein Silver/Pmel17. However, correctly targeted, full-length Silver/Pmel17 cannot form fibers. Proteolytic processing in endosomal compartments and the generation of a lumenal Malpha fragment that is incorporated into amyloid-like structures is also essential. Dominant White (DWhite), a mutant form of Silver/Pmel17 first described in chicken, causes disorganized fibers and severe hypopigmentation due to melanocyte death. Surprisingly, the DWhite mutation is an insertion of three amino acids into the transmembrane domain; the DWhite-Malpha fragment is unaffected. To determine the functional importance of the transmembrane domain in organized fibril assembly, we investigated membrane trafficking and multimerization of Silver/Pmel17/DWhite proteins. We demonstrate that the DWhite mutation changes lipid interactions and disulfide bond-mediated associations of lumenal domains. Thus, partitioning into membrane microdomains and effects on conformation explain how the transmembrane region may contribute to the structural integrity of Silver/Pmel17 oligomers or influence toxic, amyloidogenic properties.
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Electron tomography of early melanosomes: implications for melanogenesis and the generation of fibrillar amyloid sheets. Proc Natl Acad Sci U S A 2008; 105:19726-31. [PMID: 19033461 DOI: 10.1073/pnas.0803488105] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Melanosomes are lysosome-related organelles (LROs) in which melanins are synthesized and stored. Early stage melanosomes are characterized morphologically by intralumenal fibrils upon which melanins are deposited in later stages. The integral membrane protein Pmel17 is a component of the fibrils, can nucleate fibril formation in the absence of other pigment cell-specific proteins, and forms amyloid-like fibrils in vitro. Before fibril formation Pmel17 traffics through multivesicular endosomal compartments, but how these compartments participate in downstream events leading to fibril formation is not fully known. By using high-pressure freezing of MNT-1 melanoma cells and freeze substitution to optimize ultrastructural preservation followed by double tilt 3D electron tomography, we show that the amyloid-like fibrils begin to form in multivesicular compartments, where they radiate from the luminal side of intralumenal membrane vesicles. The fibrils in fully formed stage II premelanosomes organize into sheet-like arrays and exclude the remaining intralumenal vesicles, which are smaller and often in continuity with the limiting membrane. These observations indicate that premelanosome fibrils form in association with intralumenal endosomal membranes. We suggest that similar processes regulate amyloid formation in pathological models.
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Abstract
Amyloidogenesis is the aggregation of soluble proteins into structurally conserved fibers. Amyloid fibers are distinguished by their resistance to proteinase K, tinctorial properties and beta-sheet-rich secondary structure. Amyloid formation is a hallmark of many human diseases including Alzheimer's, Huntington's and the prion diseases. Therefore, understanding amyloidogenesis will provide insights into the development of therapeutics that target these debilitating diseases. A new class of ;functional' amyloids promises a unique glimpse at how nature has harnessed the amyloid fiber to accomplish important physiological tasks. Functional amyloids are produced by organisms spanning all aspects of cellular life. Herein we review amyloidogenesis, with special attention focused on the similarities and differences between the best characterized disease-associated amyloidogenic protein amyloid-beta and the formation of several functional amyloids. The implications of studying functional amyloidogenesis and the strategies organisms employ to limit exposure to toxic intermediates will also be discussed.
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Affiliation(s)
- Neal D Hammer
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI 48109-0620, USA
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Kokkinopoulos I, Pearson R, MacNeil A, Dhomen N, MacLaren R, Ali R, Sowden J. Isolation and characterisation of neural progenitor cells from the adult Chx10orJ/orJ central neural retina. Mol Cell Neurosci 2008; 38:359-73. [DOI: 10.1016/j.mcn.2008.03.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2007] [Revised: 03/20/2008] [Accepted: 03/25/2008] [Indexed: 12/29/2022] Open
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Kuehn C, Weikard R. Multiple splice variants within the bovine silver homologue (SILV) gene affecting coat color in cattle indicate a function additional to fibril formation in melanophores. BMC Genomics 2007; 8:335. [PMID: 17892572 PMCID: PMC2099443 DOI: 10.1186/1471-2164-8-335] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2007] [Accepted: 09/24/2007] [Indexed: 11/16/2022] Open
Abstract
Background The silver homologue(SILV) gene plays a major role in melanosome development. SILV is a target for studies concerning melanoma diagnostics and therapy in humans as well as on skin and coat color pigmentation in many species ranging from zebra fish to mammals. However, the precise functional cellular mechanisms, in which SILV is involved, are still not completely understood. While there are many studies addressing SILV function upon a eumelaneic pigment background, there is a substantial lack of information regarding the further relevance of SILV, e.g. for phaeomelanosome development. Results In contrast to previous results in other species reporting SILV expression exclusively in pigmented tissues, our experiments provide evidence that the bovine SILV gene is expressed in a variety of tissues independent of pigmentation. Our data show that the bovine SILV gene generates an unexpectedly large number of different transcripts occurring in skin as well as in non-pigmented tissues, e.g. liver or mammary gland. The alternative splice sites are generated by internal splicing and primarily remove complete exons. Alternative splicing predominantly affects the repeat domain of the protein, which has a functional key role in fibril formation during eumelanosome development. Conclusion The expression of the bovine SILV gene independent of pigmentation suggests SILV functions exceeding melanosome development in cattle. This hypothesis is further supported by transcript variants lacking functional key elements of the SILV protein relevant for eumelanosome development. Thus, the bovine SILV gene can serve as a model for the investigation of the putative additional functions of SILV. Furthermore, the splice variants of the bovine SILV gene represent a comprehensive natural model to refine the knowledge about functional domains in the SILV protein. Our study exemplifies that the extent of alternative splicing is presumably much higher than previously estimated and that alternatively spliced transcripts presumably can generate molecules of deviating function compared to their constitutive counterpart.
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Affiliation(s)
- Christa Kuehn
- Research Institute for the Biology of Farm Animals (FBN), Res. Unit Molecular Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
| | - Rosemarie Weikard
- Research Institute for the Biology of Farm Animals (FBN), Res. Unit Molecular Biology, Wilhelm-Stahl-Allee 2, D-18196 Dummerstorf, Germany
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Braasch I, Schartl M, Volff JN. Evolution of pigment synthesis pathways by gene and genome duplication in fish. BMC Evol Biol 2007. [PMID: 17498288 DOI: 10.1186/1471-2148-7-74.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Coloration and color patterning belong to the most diverse phenotypic traits in animals. Particularly, teleost fishes possess more pigment cell types than any other group of vertebrates. As the result of an ancient fish-specific genome duplication (FSGD), teleost genomes might contain more copies of genes involved in pigment cell development than tetrapods. No systematic genomic inventory allowing to test this hypothesis has been drawn up so far for pigmentation genes in fish, and almost nothing is known about the evolution of these genes in different fish lineages. RESULTS Using a comparative genomic approach including phylogenetic reconstructions and synteny analyses, we have studied two major pigment synthesis pathways in teleost fish, the melanin and the pteridine pathways, with respect to different types of gene duplication. Genes encoding three of the four enzymes involved in the synthesis of melanin from tyrosine have been retained as duplicates after the FSGD. In the pteridine pathway, two cases of duplicated genes originating from the FSGD as well as several lineage-specific gene duplications were observed. In both pathways, genes encoding the rate-limiting enzymes, tyrosinase and GTP-cyclohydrolase I (GchI), have additional paralogs in teleosts compared to tetrapods, which have been generated by different modes of duplication. We have also observed a previously unrecognized diversity of gchI genes in vertebrates. In addition, we have found evidence for divergent resolution of duplicated pigmentation genes, i.e., differential gene loss in divergent teleost lineages, particularly in the tyrosinase gene family. CONCLUSION Mainly due to the FSGD, teleost fishes apparently have a greater repertoire of pigment synthesis genes than any other vertebrate group. Our results support an important role of the FSGD and other types of duplication in the evolution of pigmentation in fish.
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Affiliation(s)
- Ingo Braasch
- University of Würzburg, Physiological Chemistry I, Biozentrum, Am Hubland, Würzburg, Germany.
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Braasch I, Schartl M, Volff JN. Evolution of pigment synthesis pathways by gene and genome duplication in fish. BMC Evol Biol 2007; 7:74. [PMID: 17498288 PMCID: PMC1890551 DOI: 10.1186/1471-2148-7-74] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Accepted: 05/11/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Coloration and color patterning belong to the most diverse phenotypic traits in animals. Particularly, teleost fishes possess more pigment cell types than any other group of vertebrates. As the result of an ancient fish-specific genome duplication (FSGD), teleost genomes might contain more copies of genes involved in pigment cell development than tetrapods. No systematic genomic inventory allowing to test this hypothesis has been drawn up so far for pigmentation genes in fish, and almost nothing is known about the evolution of these genes in different fish lineages. RESULTS Using a comparative genomic approach including phylogenetic reconstructions and synteny analyses, we have studied two major pigment synthesis pathways in teleost fish, the melanin and the pteridine pathways, with respect to different types of gene duplication. Genes encoding three of the four enzymes involved in the synthesis of melanin from tyrosine have been retained as duplicates after the FSGD. In the pteridine pathway, two cases of duplicated genes originating from the FSGD as well as several lineage-specific gene duplications were observed. In both pathways, genes encoding the rate-limiting enzymes, tyrosinase and GTP-cyclohydrolase I (GchI), have additional paralogs in teleosts compared to tetrapods, which have been generated by different modes of duplication. We have also observed a previously unrecognized diversity of gchI genes in vertebrates. In addition, we have found evidence for divergent resolution of duplicated pigmentation genes, i.e., differential gene loss in divergent teleost lineages, particularly in the tyrosinase gene family. CONCLUSION Mainly due to the FSGD, teleost fishes apparently have a greater repertoire of pigment synthesis genes than any other vertebrate group. Our results support an important role of the FSGD and other types of duplication in the evolution of pigmentation in fish.
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Affiliation(s)
- Ingo Braasch
- University of Würzburg, Physiological Chemistry I, Biozentrum, Am Hubland, 97074 Würzburg, Germany
| | - Manfred Schartl
- University of Würzburg, Physiological Chemistry I, Biozentrum, Am Hubland, 97074 Würzburg, Germany
| | - Jean-Nicolas Volff
- University of Würzburg, Physiological Chemistry I, Biozentrum, Am Hubland, 97074 Würzburg, Germany
- Institut de Génomique Fonctionnelle, Université de Lyon, F-69003, France, INRA; CNRS, Université Lyon 1, Ecole Normale Supérieure, F-69364, France
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Reissmann M, Bierwolf J, Brockmann GA. Two SNPs in the SILV gene are associated with silver coat colour in ponies. Anim Genet 2007; 38:1-6. [PMID: 17257181 DOI: 10.1111/j.1365-2052.2006.01553.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In horses, a pigment dilution acting only on black eumelanin is the so-called silver coat colour, which is characterized by a chocolate-to-reddish body with a white mane and tail. Using information from other species, we focused our study on SILV as a possible candidate gene for the equine silver phenotype. A 1559-bp genomic fragment was sequenced in 24 horses, and five SNPs were detected. Two of the five SNPs (DQ665301:g.697A>T and DQ665301:g.1457C>T) were genotyped in 112 horses representing eight colour phenotypes. Both mutations were completely associated with the silver phenotype: all eumelanin-producing horses (blacks and bays) with atypical white mane and tail were carriers of the [g.697T; g.1457T] haplotype. We identified this haplotype as well as the silver phenotype only in Shetland ponies and Icelandic horses. Horses without eumelanin (chestnuts) were carriers of the [g.697T; g.1457T] haplotype, but they showed no phenotypic effect. The white or flaxen mane often detected in chestnuts is presumably based on another SILV mutation or on polymorphisms in other genes.
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Affiliation(s)
- M Reissmann
- Breeding Biology and Molecular Genetics, Institute for Animal Sciences, Humboldt-Universität zu Berlin, D-10115 Berlin, Germany.
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Theos AC, Berson JF, Theos SC, Herman KE, Harper DC, Tenza D, Sviderskaya EV, Lamoreux ML, Bennett DC, Raposo G, Marks MS. Dual loss of ER export and endocytic signals with altered melanosome morphology in the silver mutation of Pmel17. Mol Biol Cell 2006; 17:3598-612. [PMID: 16760433 PMCID: PMC1525253 DOI: 10.1091/mbc.e06-01-0081] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Pmel17 is a pigment cell-specific integral membrane protein that participates in the formation of the intralumenal fibrils upon which melanins are deposited in melanosomes. The Pmel17 cytoplasmic domain is truncated by the mouse silver mutation, which is associated with coat hypopigmentation in certain strain backgrounds. Here, we show that the truncation interferes with at least two steps in Pmel17 intracellular transport, resulting in defects in melanosome biogenesis. Human Pmel17 engineered with the truncation found in the mouse silver mutant (hPmel17si) is inefficiently exported from the endoplasmic reticulum (ER). Localization and metabolic pulse-chase analyses with site-directed mutants and chimeric proteins show that this effect is due to the loss of a conserved C-terminal valine that serves as an ER exit signal. hPmel17si that exits the ER accumulates abnormally at the plasma membrane due to the loss of a di-leucine-based endocytic signal. The combined effects of reduced ER export and endocytosis significantly deplete Pmel17 within endocytic compartments and delay proteolytic maturation required for premelanosome-like fibrillogenesis. The ER export delay and cell surface retention are also observed for endogenous Pmel17si in melanocytes from silver mice, within which Pmel17 accumulation in premelanosomes is dramatically reduced. Mature melanosomes in these cells are larger, rounder, more highly pigmented, and less striated than in control melanocytes. These data reveal a dual sorting defect in a natural mutant of Pmel17 and support a requirement of endocytic trafficking in Pmel17 fibril formation.
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Affiliation(s)
- Alexander C. Theos
- *Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Joanne F. Berson
- *Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Sarah C. Theos
- *Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Kathryn E. Herman
- *Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Dawn C. Harper
- *Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Danièle Tenza
- Institut Curie, UMR-144, Centre National de la Recherche Scientifique, Paris, France 75005
| | - Elena V. Sviderskaya
- Division of Basic Medical Sciences, St. George’s, University of London, London SW17 0RE, United Kingdom; and
| | - M. Lynn Lamoreux
- Comparative Genetics Program, Texas A&M University, College Station, TX 77843
| | - Dorothy C. Bennett
- Division of Basic Medical Sciences, St. George’s, University of London, London SW17 0RE, United Kingdom; and
| | - Graça Raposo
- Institut Curie, UMR-144, Centre National de la Recherche Scientifique, Paris, France 75005
| | - Michael S. Marks
- *Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104
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Fowler DM, Koulov AV, Alory-Jost C, Marks MS, Balch WE, Kelly JW. Functional amyloid formation within mammalian tissue. PLoS Biol 2006; 4:e6. [PMID: 16300414 PMCID: PMC1288039 DOI: 10.1371/journal.pbio.0040006] [Citation(s) in RCA: 587] [Impact Index Per Article: 32.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2005] [Accepted: 10/31/2005] [Indexed: 11/19/2022] Open
Abstract
Amyloid is a generally insoluble, fibrous cross-β sheet protein aggregate. The process of amyloidogenesis is associated with a variety of neurodegenerative diseases including Alzheimer, Parkinson, and Huntington disease. We report the discovery of an unprecedented functional mammalian amyloid structure generated by the protein Pmel17. This discovery demonstrates that amyloid is a fundamental nonpathological protein fold utilized by organisms from bacteria to humans. We have found that Pmel17 amyloid templates and accelerates the covalent polymerization of reactive small molecules into melanin—a critically important biopolymer that protects against a broad range of cytotoxic insults including UV and oxidative damage. Pmel17 amyloid also appears to play a role in mitigating the toxicity associated with melanin formation by sequestering and minimizing diffusion of highly reactive, toxic melanin precursors out of the melanosome. Intracellular Pmel17 amyloidogenesis is carefully orchestrated by the secretory pathway, utilizing membrane sequestration and proteolytic steps to protect the cell from amyloid and amyloidogenic intermediates that can be toxic. While functional and pathological amyloid share similar structural features, critical differences in packaging and kinetics of assembly enable the usage of Pmel17 amyloid for normal function. The discovery of native Pmel17 amyloid in mammals provides key insight into the molecular basis of both melanin formation and amyloid pathology, and demonstrates that native amyloid (amyloidin) may be an ancient, evolutionarily conserved protein quaternary structure underpinning diverse pathways contributing to normal cell and tissue physiology. The authors show that native Pmel17 amyloid found in mammalian melanosomes accelerates melanin synthesis.
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Affiliation(s)
- Douglas M Fowler
- 1 Department of Chemistry and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Atanas V Koulov
- 2 Department of Cell Biology and the Institute for Childhood and Neglected Diseases, The Scripps Research Institute, La Jolla, California, United States of America
| | - Christelle Alory-Jost
- 2 Department of Cell Biology and the Institute for Childhood and Neglected Diseases, The Scripps Research Institute, La Jolla, California, United States of America
| | - Michael S Marks
- 3 Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - William E Balch
- 2 Department of Cell Biology and the Institute for Childhood and Neglected Diseases, The Scripps Research Institute, La Jolla, California, United States of America
| | - Jeffery W Kelly
- 1 Department of Chemistry and The Skaggs Institute of Chemical Biology, The Scripps Research Institute, La Jolla, California, United States of America
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Sarangarajan R, Apte SP. The polymerization of melanin: a poorly understood phenomenon with egregious biological implications. Melanoma Res 2006; 16:3-10. [PMID: 16432450 DOI: 10.1097/01.cmr.0000195699.35143.df] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Several hypotheses have explicitly implicated the role of an altered redox status of melanin in the aetiology of melanoma and macular degeneration. The balance between the intrinsic anti-oxidant and pro-oxidant properties of melanin is lost, resulting in an altered redox phenotype. We propose that such an alteration of the redox status of melanin may arise, in part, due to suboptimal conditions for the effective polymerization of melanin precursors. We suggest that a decrease in the degree of polymerization or molecular weight of the melanin polymer may cause an alteration of the redox status of the polymer towards a more pro-oxidant state. A higher propensity of smaller oligomers to complex metals, coupled with an upregulation of metallothionein expression, results in increased production of free radicals including the superoxide anion. This, in association with an increase in the rate of tyrosinase degradation, a decrease in the rate of tyrosinase activation, alterations to template protein structure or alterations in the kinetics of the oxidation of tyrosine via the Raper-Mason pathway, may result in an overcoming of the cellular anti-oxidant pool, an increased susceptibility to oxidative stress and alterations to the reaction kinetics of melanogenesis, thus setting up a cycle of increasing oxidative stress and proliferation leading to the leakage of melanin monomers outside the organelle, thereby causing cytotoxicity and necrosis.
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Affiliation(s)
- Rangaprasad Sarangarajan
- Department of Pharmaceutical Sciences, Massachusetts College of Pharmacy and Health Sciences, Worcester, Massachusetts, USA
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Clark LA, Wahl JM, Rees CA, Murphy KE. Retrotransposon insertion in SILV is responsible for merle patterning of the domestic dog. Proc Natl Acad Sci U S A 2006; 103:1376-81. [PMID: 16407134 PMCID: PMC1360527 DOI: 10.1073/pnas.0506940103] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2005] [Accepted: 11/26/2005] [Indexed: 11/18/2022] Open
Abstract
Merle is a pattern of coloring observed in the coat of the domestic dog and is characterized by patches of diluted pigment. This trait is inherited in an autosomal, incompletely dominant fashion. Dogs heterozygous or homozygous for the merle locus exhibit a wide range of auditory and ophthalmologic abnormalities, which are similar to those observed for the human auditory-pigmentation disorder Waardenburg syndrome. Mutations in at least five genes have been identified as causative for Waardenburg syndrome; however, the genetic bases for all cases have not been determined. Linkage disequilibrium was identified for a microsatellite marker with the merle phenotype in the Shetland Sheepdog. The marker is located in a region of CFA10 that exhibits conservation of synteny with HSA12q13. This region of the human genome contains SILV, a gene important in mammalian pigmentation. Therefore, this gene was evaluated as a candidate for merle patterning. A short interspersed element insertion at the boundary of intron 10/exon 11 was found, and this insertion segregates with the merle phenotype in multiple breeds. Another finding was deletions within the oligo(dA)-rich tail of the short interspersed element. Such deletions permit normal pigmentation. These data show that SILV is responsible for merle patterning and is associated with impaired function of the auditory and ophthalmologic systems. Although the mutant phenotype of SILV in the human is unknown, these results make it an intriguing candidate gene for human auditory-pigmentation disorders.
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Affiliation(s)
- Leigh Anne Clark
- Departments of Pathobiology and Small Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843, USA
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Theos AC, Truschel ST, Raposo G, Marks MS. The Silver locus product Pmel17/gp100/Silv/ME20: controversial in name and in function. ACTA ACUST UNITED AC 2005; 18:322-36. [PMID: 16162173 PMCID: PMC2788625 DOI: 10.1111/j.1600-0749.2005.00269.x] [Citation(s) in RCA: 172] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mouse coat color mutants have led to the identification of more than 120 genes that encode proteins involved in all aspects of pigmentation, from the regulation of melanocyte development and differentiation to the transcriptional activation of pigment genes, from the enzymatic formation of pigment to the control of melanosome biogenesis and movement [Bennett and Lamoreux (2003) Pigment Cell Res. 16, 333]. One of the more perplexing of the identified mouse pigment genes is encoded at the Silver locus, first identified by Dunn and Thigpen [(1930) J. Heredity 21, 495] as responsible for a recessive coat color dilution that worsened with age on black backgrounds. The product of the Silver gene has since been discovered numerous times in different contexts, including the initial search for the tyrosinase gene, the characterization of major melanosome constituents in various species, and the identification of tumor-associated antigens from melanoma patients. Each discoverer provided a distinct name: Pmel17, gp100, gp95, gp85, ME20, RPE1, SILV and MMP115 among others. Although all its functions are unlikely to have yet been fully described, the protein clearly plays a central role in the biogenesis of the early stages of the pigment organelle, the melanosome, in birds, and mammals. As such, we will refer to the protein in this review simply as pre-melanosomal protein (Pmel). This review will summarize the structural and functional aspects of Pmel and its role in melanosome biogenesis.
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Affiliation(s)
- Alexander C. Theos
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Steven T. Truschel
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Graça Raposo
- Institut Curie, Centre National de la Recherche Scientifique, UMR-144, Paris Cedex, France
| | - Michael S. Marks
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Address correspondence to Michael S. Marks,
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Stennett LS, Riker AI, Kroll TM, ChaMberlin J, Miki T, Nickoloff BJ, Le Poole IC. Expression of gp100 and CDK2 in melanoma cells is not co-regulated by a shared promoter region. ACTA ACUST UNITED AC 2005; 17:525-32. [PMID: 15357840 DOI: 10.1111/j.1600-0749.2004.00180.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Expression of the pigmentation-associated gene PMel17 is regulated by a 1 kB promoter region shared between the PMel17 and CDK2 genes. The encoded melanosomal glycoprotein gp100 and the cell cycle regulatory protein CDK2 are transcribed in opposite directions. Luciferase reporter constructs were generated for subregions of the promoter containing 0, 1, 2 or 3 putative binding sites for transcription factors with basic helix-loop-helix (bHLH) motifs. The potential contribution of bHLH transcription factor microphthalmia transcription factor (MITF) to promoter activity was investigated by re-introducing microphthalmia into melanoma cells lacking expression. A bi-directional reporter construct was generated to investigate potential co-regulation of gp100 and CDK2 transcription. Promoter activity was assessed in presence and absence of phorbol ester tetradecanoyl phorbol 13-acetate (TPA). FACS analysis and immunohistology served to evaluate co-regulation of gp100 and CDK2 expression at the protein level. The full-length promoter, including a consensus binding site for MITF was found to contain sequences that suppressed gp100 expression. Introduction of MITF into non-expressing 1123 melanoma cells did not restore gp100 expression levels. A lack of coregulation for gp100 and CDK2 as suggested by immunostaining was supported by findings of dissimilar expression regulation by TPA for either gene. The current study provides insight into transcriptional regulation of the PMel17 and CDK2 genes, important to identify strategies for modulating expression of gp100 and CDK2 proteins by melanoma cells.
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Affiliation(s)
- Lawrence S Stennett
- Cardinal Bernardin Cancer Center, Loyola University Chicago, Maywood, IL, USA
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Tolleson WH. Human melanocyte biology, toxicology, and pathology. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2005; 23:105-61. [PMID: 16291526 DOI: 10.1080/10590500500234970] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The human melanocytes of the skin, hair, eyes, inner ears, and covering of the brain provide physiologic functions important in organ development and maintenance. Melanocytes develop from embryonic neural crest progenitors and share certain traits with other neural crest derivatives found in the adrenal medulla and peripheral nervous system. The distinctive metabolic feature of melanocytes is the synthesis of melanin pigments from tyrosine and cysteine precursors involving over 100 gene products. These complex biochemical mechanisms create inherent liabilities for melanocytic cells if intracellular systems necessary for compartmentalization, detoxification, or repair are compromised. Melanocyte disorders may involve pigmentation, sensory functions, autoimmunity, or malignancy. Environmental factors such as ultraviolet radiation and chemical exposures, combined with heritable traits, represent the principal hazards associated with melanocyte disorders.
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Affiliation(s)
- William H Tolleson
- National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA.
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50
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Slominski A, Tobin DJ, Shibahara S, Wortsman J. Melanin pigmentation in mammalian skin and its hormonal regulation. Physiol Rev 2004; 84:1155-228. [PMID: 15383650 DOI: 10.1152/physrev.00044.2003] [Citation(s) in RCA: 1350] [Impact Index Per Article: 67.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cutaneous melanin pigment plays a critical role in camouflage, mimicry, social communication, and protection against harmful effects of solar radiation. Melanogenesis is under complex regulatory control by multiple agents interacting via pathways activated by receptor-dependent and -independent mechanisms, in hormonal, auto-, para-, or intracrine fashion. Because of the multidirectional nature and heterogeneous character of the melanogenesis modifying agents, its controlling factors are not organized into simple linear sequences, but they interphase instead in a multidimensional network, with extensive functional overlapping with connections arranged both in series and in parallel. The most important positive regulator of melanogenesis is the MC1 receptor with its ligands melanocortins and ACTH, whereas among the negative regulators agouti protein stands out, determining intensity of melanogenesis and also the type of melanin synthesized. Within the context of the skin as a stress organ, melanogenic activity serves as a unique molecular sensor and transducer of noxious signals and as regulator of local homeostasis. In keeping with these multiple roles, melanogenesis is controlled by a highly structured system, active since early embryogenesis and capable of superselective functional regulation that may reach down to the cellular level represented by single melanocytes. Indeed, the significance of melanogenesis extends beyond the mere assignment of a color trait.
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Affiliation(s)
- Andrzej Slominski
- Dept. of Pathology, Suite 599, University of Tennessee Health Science Center, 930 Madison Avenue, Memphis, TN 38163, USA.
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