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Da Graça J, Delevoye C, Morel E. Morphodynamical adaptation of the endolysosomal system to stress. FEBS J 2024. [PMID: 38706230 DOI: 10.1111/febs.17154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Revised: 03/28/2024] [Accepted: 04/25/2024] [Indexed: 05/07/2024]
Abstract
In eukaryotes, the spatiotemporal control of endolysosomal organelles is central to the maintenance of homeostasis. By providing an interface between the cytoplasm and external environment, the endolysosomal system is placed at the forefront of the response to a wide range of stresses faced by cells. Endosomes are equipped with a dedicated set of membrane-associated proteins that ensure endosomal functions as well as crosstalk with the secretory or the autophagy pathways. Morphodynamical processes operate through local spatialization of subdomains, enabling specific remodeling and membrane contact capabilities. Consequently, the plasticity of endolysosomal organelles can be considered a robust and flexible tool exploited by cells to cope with homeostatic deviations. In this review, we provide insights into how the cellular responses to various stresses (osmotic, UV, nutrient deprivation, or pathogen infections) rely on the adaptation of the endolysosomal system morphodynamics.
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Affiliation(s)
- Juliane Da Graça
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, France
| | - Cédric Delevoye
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, France
- Institut Curie, PSL Research University, CNRS, UMR144, Structure and Membrane Compartments, Paris, France
| | - Etienne Morel
- Université Paris Cité, INSERM UMR-S1151, CNRS UMR-S8253, Institut Necker Enfants Malades, France
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Castellani G, Buccarelli M, Arasi MB, Rossi S, Pisanu ME, Bellenghi M, Lintas C, Tabolacci C. BRAF Mutations in Melanoma: Biological Aspects, Therapeutic Implications, and Circulating Biomarkers. Cancers (Basel) 2023; 15:4026. [PMID: 37627054 PMCID: PMC10452867 DOI: 10.3390/cancers15164026] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/03/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Melanoma is an aggressive form of skin cancer resulting from the malignant transformation of melanocytes. Recent therapeutic approaches, including targeted therapy and immunotherapy, have improved the prognosis and outcome of melanoma patients. BRAF is one of the most frequently mutated oncogenes recognised in melanoma. The most frequent oncogenic BRAF mutations consist of a single point mutation at codon 600 (mostly V600E) that leads to constitutive activation of the BRAF/MEK/ERK (MAPK) signalling pathway. Therefore, mutated BRAF has become a useful target for molecular therapy and the use of BRAF kinase inhibitors has shown promising results. However, several resistance mechanisms invariably develop leading to therapeutic failure. The aim of this manuscript is to review the role of BRAF mutational status in the pathogenesis of melanoma and its impact on differentiation and inflammation. Moreover, this review focuses on the mechanisms responsible for resistance to targeted therapies in BRAF-mutated melanoma and provides an overview of circulating biomarkers including circulating tumour cells, circulating tumour DNA, and non-coding RNAs.
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Affiliation(s)
- Giorgia Castellani
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy; (G.C.); (M.B.); (M.B.A.); (S.R.)
| | - Mariachiara Buccarelli
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy; (G.C.); (M.B.); (M.B.A.); (S.R.)
| | - Maria Beatrice Arasi
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy; (G.C.); (M.B.); (M.B.A.); (S.R.)
| | - Stefania Rossi
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy; (G.C.); (M.B.); (M.B.A.); (S.R.)
| | - Maria Elena Pisanu
- High Resolution NMR Unit, Core Facilities, Istituto Superiore di Sanità, 00161 Rome, Italy;
| | - Maria Bellenghi
- Center for Gender-Specific Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy;
| | - Carla Lintas
- Research Unit of Medical Genetics, Department of Medicine, Università Campus Bio-Medico di Roma, 00128 Rome, Italy;
- Operative Research Unit of Medical Genetics, Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Rome, Italy
| | - Claudio Tabolacci
- Department of Oncology and Molecular Medicine, Istituto Superiore di Sanità, 00161 Rome, Italy; (G.C.); (M.B.); (M.B.A.); (S.R.)
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Kawaguchi K, Watanabe M, Furukawa S, Koga K, Kanamori H, Ikemoto MJ, Takashima S, Maeda M, Oh-Hashi K, Hirata Y, Furuta K, Takemori H. Intermittent inhibition of FYVE finger-containing phosphoinositide kinase induces melanosome degradation in B16F10 melanoma cells. Mol Biol Rep 2023:10.1007/s11033-023-08536-9. [PMID: 37248430 DOI: 10.1007/s11033-023-08536-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 05/17/2023] [Indexed: 05/31/2023]
Abstract
BACKGROUND Melanosomes are lysosome-related organelles that contain melanogenic factors and synthesize melanin as they mature. FYVE finger-containing phosphoinositide kinase (PIKfyve) regulates late endosome and lysosome morphology, vesicle trafficking, and autophagy. In melanocytes, PIKfyve inhibition has been reported to induce hypopigmentation due to impairments in the metabolism of early-stage melanosomes. METHODS AND RESULTS Here, we report a new type of melanosome metabolism: post-PIKfyve inhibition, which was found during the characterization of the endosome/lysosome fluoroprobe GIF-2250. In B16F10 mouse melanoma cells, GIF-2250 highlighted vesicles positive for lysosomal-associated membrane protein 1 (lysosome marker) and other endosome/lysosome markers (CD63 and Rab7/9). When cells were continuously treated with PIKfyve inhibitors, intracellular vacuoles formed, while GIF-2250 fluorescence signals diminished and were diffusely distributed in the vacuoles. After removal of the PIKfyve inhibitors, the GIF-2250 signal intensity was restored, and some GIF-2250-positive vesicles wrapped the melanosomes, which spun at high speed. In addition, intermittent PIKfyve inhibition caused melanin diffusion in the vacuoles and possible leakage into the cytoplasmic compartments, and melanosome degradation was detected by a transmission electron microscope. Melanosome degradation was accompanied by decreased levels of melanin synthesis enzymes and increased levels of the autophagosome maker LC3BII, which is also associated with early melanosomes. However, the protein levels of p62, which is degraded during autophagy, were increased, suggesting an impairment in autophagy flux during intermittent PIKfyve inhibition. Moreover, the autophagy inhibitor 3-methyladenine does not affect these protein levels, suggesting that the melanosome degradation by the intermittent inhibition of PIKfyve is not mediated by canonical autophagy. CONCLUSIONS In conclusion, disturbance of PIKfyve activity induces melanosome degradation in a canonical autophagy-independent manner.
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Affiliation(s)
- Kyoka Kawaguchi
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Miyu Watanabe
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Saho Furukawa
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Kenichi Koga
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Hiromitsu Kanamori
- Department of Cardiology, Gifu University Graduate School of Medicine, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Mitsushi J Ikemoto
- Health and Medical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, 305-8566, Ibaraki, Japan
- Graduate School of Science, Toho University, 2-2-1 Miyama, Funabashi, 274-8510, Chiba, Japan
- Advanced Research Initiative for Human High Performance (ARIHHP), Faculty of Health and Sports Sciences, University of Tsukuba, Tsukuba, 305-8574, Japan
| | - Shigeo Takashima
- Institute for Glycocore Research (iGCORE), Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
- The United Graduate School of Drug Discovery and Medical Information Sciences of Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Miwa Maeda
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Kentaro Oh-Hashi
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
- The United Graduate School of Drug Discovery and Medical Information Sciences of Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Yoko Hirata
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
- The United Graduate School of Drug Discovery and Medical Information Sciences of Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Kyoji Furuta
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
- The United Graduate School of Drug Discovery and Medical Information Sciences of Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan
| | - Hiroshi Takemori
- Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan.
- The United Graduate School of Drug Discovery and Medical Information Sciences of Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan.
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A Network of MicroRNAs and mRNAs Involved in Melanosome Maturation and Trafficking Defines the Lower Response of Pigmentable Melanoma Cells to Targeted Therapy. Cancers (Basel) 2023; 15:cancers15030894. [PMID: 36765859 PMCID: PMC9913661 DOI: 10.3390/cancers15030894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 01/16/2023] [Accepted: 01/23/2023] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The ability to increase their degree of pigmentation is an adaptive response that confers pigmentable melanoma cells higher resistance to BRAF inhibitors (BRAFi) compared to non-pigmentable melanoma cells. METHODS Here, we compared the miRNome and the transcriptome profile of pigmentable 501Mel and SK-Mel-5 melanoma cells vs. non-pigmentable A375 melanoma cells, following treatment with the BRAFi vemurafenib (vem). In depth bioinformatic analyses (clusterProfiler, WGCNA and SWIMmeR) allowed us to identify the miRNAs, mRNAs and biological processes (BPs) that specifically characterize the response of pigmentable melanoma cells to the drug. Such BPs were studied using appropriate assays in vitro and in vivo (xenograft in zebrafish embryos). RESULTS Upon vem treatment, miR-192-5p, miR-211-5p, miR-374a-5p, miR-486-5p, miR-582-5p, miR-1260a and miR-7977, as well as GPR143, OCA2, RAB27A, RAB32 and TYRP1 mRNAs, are differentially expressed only in pigmentable cells. These miRNAs and mRNAs belong to BPs related to pigmentation, specifically melanosome maturation and trafficking. In fact, an increase in the number of intracellular melanosomes-due to increased maturation and/or trafficking-confers resistance to vem. CONCLUSION We demonstrated that the ability of pigmentable cells to increase the number of intracellular melanosomes fully accounts for their higher resistance to vem compared to non-pigmentable cells. In addition, we identified a network of miRNAs and mRNAs that are involved in melanosome maturation and/or trafficking. Finally, we provide the rationale for testing BRAFi in combination with inhibitors of these biological processes, so that pigmentable melanoma cells can be turned into more sensitive non-pigmentable cells.
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Nrf2 Pathway and Autophagy Crosstalk: New Insights into Therapeutic Strategies for Ischemic Cerebral Vascular Diseases. Antioxidants (Basel) 2022; 11:antiox11091747. [PMID: 36139821 PMCID: PMC9495910 DOI: 10.3390/antiox11091747] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/27/2022] [Accepted: 08/30/2022] [Indexed: 11/17/2022] Open
Abstract
Cerebrovascular disease is highly prevalent and has a complex etiology and variable pathophysiological activities. It thus poses a serious threat to human life and health. Currently, pathophysiological research on cerebrovascular diseases is gradually improving, and oxidative stress and autophagy have been identified as important pathophysiological activities that are gradually attracting increasing attention. Many studies have found some effects of oxidative stress and autophagy on cerebrovascular diseases, and studies on the crosstalk between the two in cerebrovascular diseases have made modest progress. However, further, more detailed studies are needed to determine the specific mechanisms. This review discusses nuclear factor erythroid 2-related factor 2 (Nrf2) molecules, which are closely associated with oxidative stress and autophagy, and the crosstalk between them, with the aim of providing clues for studying the two important pathophysiological changes and their crosstalk in cerebrovascular diseases as well as exploring new target treatments.
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Lee KW, Kim M, Lee SH, Kim KD. The Function of Autophagy as a Regulator of Melanin Homeostasis. Cells 2022; 11:cells11132085. [PMID: 35805169 PMCID: PMC9265842 DOI: 10.3390/cells11132085] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 06/24/2022] [Accepted: 06/28/2022] [Indexed: 12/18/2022] Open
Abstract
Melanosomes are melanocyte-specific organelles that protect cells from ultraviolet (UV)-induced deoxyribonucleic acid damage through the production and accumulation of melanin and are transferred from melanocytes to keratinocytes. The relatively well-known process by which melanin is synthesized from melanocytes is known as melanogenesis. The relationship between melanogenesis and autophagy is attracting the attention of researchers because proteins associated with autophagy, such as WD repeat domain phosphoinositide-interacting protein 1, microtubule-associated protein 1 light chain 3, autophagy-related (ATG)7, ATG4, beclin-1, and UV-radiation resistance-associated gene, contribute to the melanogenesis signaling pathway. Additionally, there are reports that some compounds used as whitening cosmetics materials induce skin depigmentation through autophagy. Thus, the possibility that autophagy is involved in the removal of melanin has been suggested. To date, however, there is a lack of data on melanosome autophagy and its underlying mechanism. This review highlights the importance of autophagy in melanin homeostasis by providing an overview of melanogenesis, autophagy, the autophagy machinery involved in melanogenesis, and natural compounds that induce autophagy-mediated depigmentation.
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Affiliation(s)
- Ki Won Lee
- PMBBRC, Gyeongsang National University, Jinju 52828, Korea;
| | - Minju Kim
- Division of Applied Life Science, Gyeongsang National University, Jinju 52828, Korea; (M.K.); (S.H.L.)
| | - Si Hyeon Lee
- Division of Applied Life Science, Gyeongsang National University, Jinju 52828, Korea; (M.K.); (S.H.L.)
| | - Kwang Dong Kim
- PMBBRC, Gyeongsang National University, Jinju 52828, Korea;
- Division of Applied Life Science, Gyeongsang National University, Jinju 52828, Korea; (M.K.); (S.H.L.)
- Correspondence: ; Tel.: +82-55-772-1365; Fax: +82-55-772-1359
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Dong X, Zeng W, Zhang W, Lan Y, Wang Y, Feng J, Gu L, Lu H. Opsin 3 Regulates Melanogenesis in Human Congenital Melanocytic Nevus Cells via Functional Interaction with BRAFV600E. J Invest Dermatol 2022; 142:3020-3029.e5. [DOI: 10.1016/j.jid.2022.04.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Revised: 03/22/2022] [Accepted: 04/10/2022] [Indexed: 10/31/2022]
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Bustos SO, Leal Santos N, Chammas R, Andrade LNDS. Secretory Autophagy Forges a Therapy Resistant Microenvironment in Melanoma. Cancers (Basel) 2022; 14:234. [PMID: 35008395 PMCID: PMC8749976 DOI: 10.3390/cancers14010234] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/22/2021] [Accepted: 12/28/2021] [Indexed: 12/12/2022] Open
Abstract
Melanoma is the most aggressive skin cancer characterized by high mutational burden and large heterogeneity. Cancer cells are surrounded by a complex environment, critical to tumor establishment and progression. Thus, tumor-associated stromal components can sustain tumor demands or impair cancer cell progression. One way to manage such processes is through the regulation of autophagy, both in stromal and tumor cells. Autophagy is a catabolic mechanism that provides nutrients and energy, and it eliminates damaged organelles by degradation and recycling of cellular elements. Besides this primary function, autophagy plays multiple roles in the tumor microenvironment capable of affecting cell fate. Evidence demonstrates the existence of novel branches in the autophagy system related to cytoplasmic constituent's secretion. Hence, autophagy-dependent secretion assembles a tangled network of signaling that potentially contributes to metabolism reprogramming, immune regulation, and tumor progression. Here, we summarize the current awareness regarding secretory autophagy and the intersection with exosome biogenesis and release in melanoma and their role in tumor resistance. In addition, we present and discuss data from public databases concerning autophagy and exosome-related genes as important mediators of melanoma behavior. Finally, we will present the main challenges in the field and strategies to translate most of the pre-clinical findings to clinical practice.
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Affiliation(s)
- Silvina Odete Bustos
- Center for Translational Research in Oncology (LIM24), Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Sao Paulo 01246-000, Brazil; (N.L.S.); (R.C.)
| | | | | | - Luciana Nogueira de Sousa Andrade
- Center for Translational Research in Oncology (LIM24), Instituto do Câncer do Estado de São Paulo, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, Sao Paulo 01246-000, Brazil; (N.L.S.); (R.C.)
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Yu H, Lin X, Huang Y, Cheng H, Seifert O. The Difference in Expression of Autophagy-Related Proteins in Lesional and Perilesional Skin in Adult Patients with Active and Stable Generalized Vitiligo-A Cross-Sectional Pilot Study. Indian J Dermatol 2021; 66:331-336. [PMID: 34759388 PMCID: PMC8530050 DOI: 10.4103/ijd.ijd_774_19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background: Autophagy plays an important role in maintaining intracellular homeostasis and is essential for cell survival and cell death. Dysfunction of autophagy has been described in many autoimmune diseases but data on vitiligo are scarce. Aims: The aim of this pilot study was to investigate the expression of autophagy-related proteins in patients with vitiligo. Methods: Western blotting was used to analyze the expression of microtubule-associated protein light chain 3 (LC3II/I), autophagy-related gene 5 (Agt5), mammalian target of rapamycin (mTOR) and p62 in lesional and perilesional vitiligo skin from seven patients with active generalized vitiligo and nine patients with stable generalized vitiligo compared to control skin from six healthy subjects. Results: Our data showed increased expression of the autophagy marker LC3II/I and decreased p62 protein expression in lesional skin of active and stable vitiligo compared to control skin (P < 0.01). No significant difference in the expression of LC3II/I and p62 was found in perilesional skin of active vitiligo patients (P > 0.05) compared to control skin. Expression of LC3II/I in stable vitiligo lesional skin was higher and p62 expression was lower compared to active vitiligo lesional skin (P < 0.01). Decreased p62 expression was shown in perilesional skin of stable vitiligo patients (P < 0.05). Agt5 protein in lesional and perilesional skin of both active and stable vitiligo patients were increased (P < 0.01 and P< 0.05) compared to control skin. The expression of mTOR protein in lesional and perilesional skin of active and stable vitiligo patients was significantly lower than in control skin (P < 0.01). Conclusions: The present study indicates increased autophagy in lesional skin in vitiligo patients. Stable vitiligo lesional skin showed increased autophagy compared to active vitiligo lesional skin. Missing activation of autophagy in active vitiligo perilesional skin suggests disturbed autophagy to be associated with vitiligo.
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Affiliation(s)
- Haiyan Yu
- Department of Dermatology, Sir Run Run Shaw Hospital, Zhejiang University Medical College, 3 Qinchun Road East, Hangzhou, Zhejiang, China
| | - Xiaoxia Lin
- Department of Dermatology, Sir Run Run Shaw Hospital, Zhejiang University Medical College, 3 Qinchun Road East, Hangzhou, Zhejiang, China
| | - Yaoyao Huang
- Department of Dermatology, Sir Run Run Shaw Hospital, Zhejiang University Medical College, 3 Qinchun Road East, Hangzhou, Zhejiang, China
| | - Hao Cheng
- Department of Dermatology, Sir Run Run Shaw Hospital, Zhejiang University Medical College, 3 Qinchun Road East, Hangzhou, Zhejiang, China
| | - Oliver Seifert
- Division of Dermatology and Venereology, Ryhov Hospital, Region Jönköping County, Jönköping, Sweden.,Department of Clinical and Experimental Medicine, Faculty of Medicine and Health Sciences, Linköping University, Linköping, Sweden
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Identification of the ceRNA networks in α-MSH-induced melanogenesis of melanocytes. Aging (Albany NY) 2020; 13:2700-2726. [PMID: 33318297 PMCID: PMC7880406 DOI: 10.18632/aging.202320] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 11/03/2020] [Indexed: 12/29/2022]
Abstract
α-MSH is known for melanogenesis stimulation, and ceRNA is a new method involved in physiological regulation. However, whether ceRNA participates in α-MSH-induced melanogenesis remains unknown. We used ceRNA array to detect the expression profiles of lncRNAs, circRNAs, and mRNAs in melanocytes after α-MSH treatment. Moreover, the melanogenesis-related ceRNA regulatory networks were screened and validated. The expression profile analysis showed that 20 lncRNAs and 49 circRNAs changed five-fold after α-MSH treatment, while 933 mRNAs changed two-fold. Based on differentially expressed genes, GO and KEGG analysis were conducted and revealed that 14 genes were enriched in melanogenesis. Then, multiple lncRNA or circRNA-miRNA-mRNA ceRNA networks and lncRNA/circRNA-miRNA-mRNA quaternary ceRNA networks were identified. Thereinto, ENST00000606533, circ_0091223, and TYR expression were upregulated in α-MSH-treated melanocytes, while their complementary miR-1291 was decreased. Dual-luciferase reporter assay further verified that ENST00000606533 and circ_0091223 could bind to miR-1291. ENST00000606533 and circ_0091223 siRNAs decreased circ_0091223, ENST00000606533, and TYR expression, but increased miR-1291 expression. Conversely, miR-1291 mimics inhibited ENST00000606533, circ_0091223, and TYR expression. Moreover, miR-1291 inhibitor could reverse the inhibitory effect of the two siRNAs on TYR expression. Hence, the "ENST00000606533/circ_0091223-miR-1291-TYR" ceRNA network is involved in α-MSH-induced melanogenesis, and ceRNA networks may be potential therapeutic targets for skin pigmentation disorders.
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Tian X, Cui Z, Liu S, Zhou J, Cui R. Melanosome transport and regulation in development and disease. Pharmacol Ther 2020; 219:107707. [PMID: 33075361 DOI: 10.1016/j.pharmthera.2020.107707] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/10/2020] [Accepted: 10/13/2020] [Indexed: 02/06/2023]
Abstract
Melanosomes are specialized membrane-bound organelles that synthesize and organize melanin, ultimately providing color to the skin, hair, and eyes. Disorders in melanogenesis and melanosome transport are linked to pigmentary diseases, such as Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, and Griscelli syndrome. Clinical cases of these pigmentary diseases shed light on the molecular mechanisms that control melanosome-related pathways. However, only an improved understanding of melanogenesis and melanosome transport will further the development of diagnostic and therapeutic approaches. Herein, we review the current literature surrounding melanosomes with particular emphasis on melanosome membrane transport and cytoskeleton-mediated melanosome transport. We also provide perspectives on melanosome regulatory mechanisms which include hormonal action, inflammation, autophagy, and organelle interactions.
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Affiliation(s)
- Xiaoyu Tian
- Institute of Biomedical Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Ziyong Cui
- Harvard College, Cambridge, MA 02138, United States of America
| | - Song Liu
- Institute of Biomedical Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China
| | - Jun Zhou
- Institute of Biomedical Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan 250014, China; State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China.
| | - Rutao Cui
- Skin Disease Research Institute, The 2nd Hospital, Zhejiang University, Hangzhou 310058, China.
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Beclin 1 controls pigmentation by changing the nuclear localization of melanogenic factor MITF. Biochem Biophys Res Commun 2020; 528:719-725. [PMID: 32513537 DOI: 10.1016/j.bbrc.2020.05.118] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 05/15/2020] [Indexed: 11/21/2022]
Abstract
The primary contributor for the determination of skin color is melanin, a pigment that is produced in specialized cells called melanocytes. At cellular level, melanin synthesis occurs through several enzymes like tyrosinase (TYR) and tyrosinase related proteins and the expression of these proteins are regulated transcriptionally by microphthalmia associated transcription factor (MITF). Melanin pigmentation is a complex process finely regulated by different transcription factors, structural proteins and enzymes. In recent times, several autophagic genes have been implicated in the regulation of pigmentation. Though previous report observed a visible loss of coat-color in heterozygous Beclin 1 mice, the role of this protein in pigmentation is yet to study in details. In this present work we intend to study the role of Beclin 1, a central autophagic factor, in pigmentation. Using human melanoma cells and primary melanocytes, we showed that Beclin 1 downregulation significantly decreased the melanin content, tyrosinase activity and the expression of TYR and tyrosinase related protein 1 (TYRP1). These effects were recapitulated in a Beclin 1 knockdown in vivo model of zebrafish. Most importantly, re-expression of Beclin 1 rescued the pigmentation-associated defects both in cellular and in organismal level indicating the specificity. Surprisingly, Beclin 1 knockdown cells did not show significant changes in MITF expression but the nuclear localization of MITF was altered. Together, these data suggest that indeed Beclin 1 is associated with melanogenesis and this effect is more likely exerted through the subcellular distribution rather than the change in expression of MITF.
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Melanogenic Inhibition and Toxicity Assessment of Flavokawain A and B on B16/F10 Melanoma Cells and Zebrafish ( Danio rerio). Molecules 2020; 25:molecules25153403. [PMID: 32731323 PMCID: PMC7436045 DOI: 10.3390/molecules25153403] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 06/30/2020] [Accepted: 07/02/2020] [Indexed: 12/14/2022] Open
Abstract
Excessive production of melanin implicates hyperpigmentation disorders. Flavokawain A (FLA) and flavokawain B (FLB) have been reported with anti-melanogenic activity, but their melanogenic inhibition and toxicity effects on the vertebrate model of zebrafish are still unknown. In the present study, cytotoxic as well as melanogenic effects of FLA and FLB on cellular melanin content and tyrosinase activity were evaluated in α-MSH-induced B16/F10 cells. Master regulator of microphthalmia-associated transcription factor (Mitf) and the other downstream melanogenic-related genes were verified via quantitative real time PCR (qPCR). Toxicity assessment and melanogenesis inhibition on zebrafish model was further observed. FLA and FLB significantly reduced the specific cellular melanin content by 4.3-fold and 9.6-fold decrement, respectively in α-MSH-induced B16/F10 cells. Concomitantly, FLA significantly reduced the specific cellular tyrosinase activity by 7-fold whilst FLB by 9-fold. The decrement of melanin production and tyrosinase activity were correlated with the mRNA suppression of Mitf which in turn down-regulate Tyr, Trp-1 and Trp-2. FLA and FLB exhibited non-toxic effects on the zebrafish model at 25 and 6.25 µM, respectively. Further experiments on the zebrafish model demonstrated successful phenotype-based depigmenting activity of FLA and FLB under induced melanogenesis. To sum up, our findings provide an important first key step for both of the chalcone derivatives to be further studied and developed as potent depigmenting agents.
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14
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Rather RA, Bhagat M, Singh SK. Oncogenic BRAF, endoplasmic reticulum stress, and autophagy: Crosstalk and therapeutic targets in cutaneous melanoma. MUTATION RESEARCH. REVIEWS IN MUTATION RESEARCH 2020; 785:108321. [PMID: 32800272 DOI: 10.1016/j.mrrev.2020.108321] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 01/07/2023]
Abstract
BRAF is a member of the RAF family of serine/threonine-specific protein kinases. Oncogenic BRAF, in particular, BRAF V600E, can disturb the normal protein folding machinery in the endoplasmic reticulum (ER) leading to accumulation of unfolded/misfolded proteins in the ER lumen, a condition known as endoplasmic reticulum (ER) stress. To alleviate such conditions, ER-stressed cells have developed a highly robust and adaptable signaling network known as unfolded protein response (UPR). UPR is ordinarily a cytoprotective response and usually operates through the induction of autophagy, an intracellular lysosomal degradation pathway that directs damaged proteins, protein aggregates, and damaged organelles for bulk degradation and recycling. Both ER stress and autophagy are involved in the progression and chemoresistance of melanoma. Melanoma, which arises as a result of malignant transformation of melanocytes, exhibits exceptionally high therapeutic resistance. Many mechanisms of therapeutic resistance have been identified in individual melanoma patients and in preclinical BRAF-driven melanoma models. Recently, it has been recognized that oncogenic BRAF interacts with GRP78 and removes its inhibitory influence on the three fundamental ER stress sensors of UPR, PERK, IRE1α, and ATF6. Dissociation of GRP78 from these ER stress sensors prompts UPR that subsequently activates cytoprotective autophagy. Thus, pharmacological inhibition of BRAF-induced ER stress-mediated autophagy can potentially resensitize BRAF mutant melanoma tumors to apoptosis. However, the underlying molecular mechanism of how oncogenic BRAF elevates the basal level of ER stress-mediated autophagy in melanoma tumors is not well characterized. A better understanding of the crosstalk between oncogenic BRAF, ER stress and autophagy may provide a rationale for improving existing cancer therapies and identify novel targets for therapeutic intervention of melanoma.
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Affiliation(s)
- Rafiq A Rather
- School of Biotechnology, University of Jammu, Jammu and Kashmir, 180006, India.
| | - Madhulika Bhagat
- School of Biotechnology, University of Jammu, Jammu and Kashmir, 180006, India
| | - Shashank K Singh
- Cancer Pharmacology Division, CSIR-Indian Institute of Integrative Medicine, Canal Road, Jammu, 180001, India
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15
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Abstract
Melanin pigments are responsible for human skin and hair color, and they protect the body from harmful ultraviolet light. The black and brown melanin pigments are synthesized in specialized lysosome-related organelles called melanosomes in melanocytes. Mature melanosomes are transported within melanocytes and transferred to adjacent keratinocytes, which constitute the principal part of human skin. The melanosomes are then deposited inside the keratinocytes and darken the skin (a process called tanning). Owing to their dark color, melanosomes can be seen easily with an ordinary light microscope, and melanosome research dates back approximately 150 years; since then, biochemical studies aimed at isolating and purifying melanosomes have been conducted. Moreover, in the last two decades, hundreds of molecules involved in regulating melanosomal functions have been identified by analyses of the genes of coat-color mutant animals and patients with genetic diseases characterized by pigment abnormalities, such as hypopigmentation. In recent years, dynamic analyses by more precise microscopic observations have revealed specific functions of a variety of molecules involved in melanogenesis. This review article focuses on the latest findings with regard to the steps (or mechanisms) involved in melanosome formation and transport of mature melanosomes within epidermal melanocytes. Finally, we will touch on current topics in melanosome research, particularly on the "melanosome transfer" and "post-transfer" steps, and discuss future directions in pigment research.
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Affiliation(s)
- Norihiko Ohbayashi
- Faculty of Medicine and Graduate School of Comprehensive Human Sciences, University of Tsukuba, Tsukuba 305-8575, Japan
| | - Mitsunori Fukuda
- Laboratory of Membrane Trafficking Mechanisms, Department of Integrative Life Sciences, Graduate School of Life Sciences, Tohoku University, Miyagi 980-8578, Japan
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16
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Fernblock® Upregulates NRF2 Antioxidant Pathway and Protects Keratinocytes from PM 2.5-Induced Xenotoxic Stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:2908108. [PMID: 32377294 PMCID: PMC7181013 DOI: 10.1155/2020/2908108] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/04/2020] [Accepted: 02/07/2020] [Indexed: 12/14/2022]
Abstract
Humans in modern industrial and postindustrial societies face sustained challenges from environmental pollutants, which can trigger tissue damage from xenotoxic stress through different mechanisms. Thus, the identification and characterization of compounds capable of conferring antioxidant effects and protection against these xenotoxins are warranted. Here, we report that the natural extract of Polypodium leucotomos named Fernblock®, known to reduce aging and oxidative stress induced by solar radiations, upregulates the NRF2 transcription factor and its downstream antioxidant targets, and this correlates with its ability to reduce inflammation, melanogenesis, and general cell damage in cultured keratinocytes upon exposure to an experimental model of fine pollutant particles (PM2.5). Our results provide evidence for a specific molecular mechanism underpinning the protective activity of Fernblock® against environmental pollutants and potentially other sources of oxidative stress and damage-induced aging.
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17
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Bejaoui M, Villareal MO, Isoda H. 3,4,5-Tri- O-Caffeoylquinic Acid Promoted Hair Pigmentation Through β-Catenin and Its Target Genes. Front Cell Dev Biol 2020; 8:175. [PMID: 32269993 PMCID: PMC7109265 DOI: 10.3389/fcell.2020.00175] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 03/03/2020] [Indexed: 12/19/2022] Open
Abstract
The hair follicle undergoes a regular cycle composed of three phases: anagen, catagen, and telogen. The life of follicular melanocytes is totally linked to the hair cycle; and during anagen or the growth phase, the melanocytes are active and produce the melanin responsible of hair shaft pigmentation. Various signaling pathways regulate the hair growth cycle and, therefore, the pigmentation; we distinguish the Wnt/β-catenin signaling pathway as it plays a major role in the development, growth, and proliferation of the melanocytes and the activation of melanogenesis enzymes and the related transcription factor. In this study, 3,4,5-tri-O-caffeoylquinic acid (TCQA), a caffeoylquinic acid derivative, stimulated the pigmentation in C3H mouse hair follicle, in human melanocytes, and B16F10 melanoma cells. An enhancement in pigmentation associated genes was observed upon TCQA treatment in vivo and in vitro. Interestingly, the expression of β-catenin was remarkably upregulated in mouse treated skin and in pigment cell lines. Moreover, TCQA upregulated CTNNB1 expression after inhibition in human melanocytes. Taken together, this study suggests that TCQA triggered β-catenin activation to enhance the pigmentation during the anagen phase of the hair cycle.
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Affiliation(s)
- Meriem Bejaoui
- School of Integrative and Global Majors (SIGMA), University of Tsukuba, Tsukuba, Japan
| | - Myra O. Villareal
- School of Integrative and Global Majors (SIGMA), University of Tsukuba, Tsukuba, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
- Alliance for Research on the Mediterranean and North Africa (ARENA), University of Tsukuba, Tsukuba, Japan
| | - Hiroko Isoda
- School of Integrative and Global Majors (SIGMA), University of Tsukuba, Tsukuba, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan
- Alliance for Research on the Mediterranean and North Africa (ARENA), University of Tsukuba, Tsukuba, Japan
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18
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Autophagy-Independent Functions of the Autophagy Machinery. Cell 2020; 177:1682-1699. [PMID: 31199916 PMCID: PMC7173070 DOI: 10.1016/j.cell.2019.05.026] [Citation(s) in RCA: 571] [Impact Index Per Article: 142.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/11/2019] [Accepted: 05/13/2019] [Indexed: 02/07/2023]
Abstract
Macroautophagy (herein referred to as autophagy) is an evolutionary ancient mechanism that culminates with the lysosomal degradation of superfluous or potentially dangerous cytosolic entities. Over the past 2 decades, the molecular mechanisms underlying several variants of autophagy have been characterized in detail. Accumulating evidence suggests that most, if not all, components of the molecular machinery for autophagy also mediate autophagy-independent functions. Here, we discuss emerging data on the non-autophagic functions of autophagy-relevant proteins.
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19
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Quach C, Song Y, Guo H, Li S, Maazi H, Fung M, Sands N, O'Connell D, Restrepo-Vassalli S, Chai B, Nemecio D, Punj V, Akbari O, Idos GE, Mumenthaler SM, Wu N, Martin SE, Hagiya A, Hicks J, Cui H, Liang C. A truncating mutation in the autophagy gene UVRAG drives inflammation and tumorigenesis in mice. Nat Commun 2019; 10:5681. [PMID: 31831743 PMCID: PMC6908726 DOI: 10.1038/s41467-019-13475-w] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 11/05/2019] [Indexed: 12/19/2022] Open
Abstract
Aberrant autophagy is a major risk factor for inflammatory diseases and cancer. However, the genetic basis and underlying mechanisms are less established. UVRAG is a tumor suppressor candidate involved in autophagy, which is truncated in cancers by a frameshift (FS) mutation and expressed as a shortened UVRAGFS. To investigate the role of UVRAGFS in vivo, we generated mutant mice that inducibly express UVRAGFS (iUVRAGFS). These mice are normal in basal autophagy but deficient in starvation- and LPS-induced autophagy by disruption of the UVRAG-autophagy complex. iUVRAGFS mice display increased inflammatory response in sepsis, intestinal colitis, and colitis-associated cancer development through NLRP3-inflammasome hyperactivation. Moreover, iUVRAGFS mice show enhanced spontaneous tumorigenesis related to age-related autophagy suppression, resultant β-catenin stabilization, and centrosome amplification. Thus, UVRAG is a crucial autophagy regulator in vivo, and autophagy promotion may help prevent/treat inflammatory disease and cancer in susceptible individuals.
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Affiliation(s)
- Christine Quach
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Ying Song
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Hongrui Guo
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, 611130, China
| | - Shun Li
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
- Key Laboratory of Biorheological Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing, 400044, China
| | - Hadi Maazi
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Marshall Fung
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Nathaniel Sands
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Douglas O'Connell
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Sara Restrepo-Vassalli
- USC Michelson Center for Convergent Bioscience, Bridge Institute, University of Southern California, Los Angeles, CA, 90089, USA
| | - Billy Chai
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Dali Nemecio
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Vasu Punj
- Department of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Omid Akbari
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Gregory E Idos
- Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA, 90089, USA
| | - Shannon M Mumenthaler
- Lawrence J. Ellison Institute for Transformative Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Nancy Wu
- Norris Comprehensive Cancer Center Transgenic/Knockout Rodent Core Facility, University of Southern California, Los Angeles, CA, 90089, USA
| | - Sue Ellen Martin
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - Ashley Hagiya
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA
| | - James Hicks
- USC Michelson Center for Convergent Bioscience, Bridge Institute, University of Southern California, Los Angeles, CA, 90089, USA
| | - Hengmin Cui
- College of Veterinary Medicine, Sichuan Agriculture University, Chengdu, 611130, China
| | - Chengyu Liang
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, CA, 90033, USA.
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20
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Delevoye C, Marks MS, Raposo G. Lysosome-related organelles as functional adaptations of the endolysosomal system. Curr Opin Cell Biol 2019; 59:147-158. [PMID: 31234051 PMCID: PMC6726539 DOI: 10.1016/j.ceb.2019.05.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/10/2019] [Accepted: 05/13/2019] [Indexed: 12/19/2022]
Abstract
Unique functions of specialised cells such as those of the immune and haemostasis systems, skin, blood vessels, lung, and bone require specialised compartments, collectively referred to as lysosome-related organelles (LROs), that share features of endosomes and lysosomes. LROs harbour unique morphological features and cell type-specific contents, and most if not all undergo regulated secretion for diverse functions. Ongoing research, largely driven by analyses of inherited diseases and their model systems, is unravelling the mechanisms involved in LRO generation, maturation, transport and secretion. A molecular understanding of these features will provide targets and markers that can be exploited for diagnosis and therapy of a myriad of diseases.
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Affiliation(s)
- Cédric Delevoye
- Structure and Membrane Compartments, Institut Curie, Paris Sciences and Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France
| | - Michael S Marks
- Dept. of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA; Dept. of Pathology and Laboratory Medicine and Dept. of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Graça Raposo
- Structure and Membrane Compartments, Institut Curie, Paris Sciences and Lettres Research University, Centre National de la Recherche Scientifique, UMR144, Paris, France.
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21
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Abstract
Ultraviolet radiation (UVR)-induced skin pigmentation, afforded by the dark organelles termed melanosomes, accounts for the first-line protection against environmental UVR that increases the risk of developing skin cancers including melanoma. We have recently discovered that UVRAG, originally identified as a BECN1-binding macroautophagy/autophagy protein, appears to have a specialized function in melanosome biogenesis beyond autophagy through its interaction with the biogenesis of lysosome-related organelles complex 1 (BLOC-1). This melanogenic function of UVRAG is controlled by the melanocyte-specific transcription factor MITF as a downstream effector of the α-melanocyte-stimulating hormone (α-MSH)-cAMP signaling in the suntan response, which is compromised in BRAF mutant melanoma. Thus we propose a new mode of UVRAG activity and regulation in melanocyte biology that may affect melanoma predisposition.
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Affiliation(s)
- Shun Li
- a Department of Molecular Microbiology and Immunology , University of Southern California , Los Angeles , CA , USA
| | - Gyu-Beom Jang
- a Department of Molecular Microbiology and Immunology , University of Southern California , Los Angeles , CA , USA
| | - Christine Quach
- a Department of Molecular Microbiology and Immunology , University of Southern California , Los Angeles , CA , USA
| | - Chengyu Liang
- a Department of Molecular Microbiology and Immunology , University of Southern California , Los Angeles , CA , USA
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