- The long-term goal of this proposed research is to elucidate the molecular basis of cutaneous melanization in order to understand the pathogenesis of human diseases affecting pigmentation and to devise treatments for them. By combining techniques of cellular and molecular biology with the power of mouse genetics, the basic mechanisms by which a melanocyte creates its specialized organelle, the melanosome, will be addressed through three specific aims over the next 5 years: (1) Elucidate the biogenesis of melanosomes. The distribution of known and newly identified melanosomal proteins will be examined in relation to other subcellular proteins. The hypothesis that melanosomes are constructed via a bipartite pathway wherein smooth ER-derived premelanosomes fuse with Golgi-derived vesicles will be tested. Immunomicroscopy, subcellular fractionation, metabolic labeling, and transfection will be used to assess how individual proteins arrive at melanosomes. By combining these techniques with the treatment of melanocytes with Agouti signal protein, which shifts production from the eu- to the pheo-melanosome, insight it is hoped will be gained into the fundamental differences between these two types of melanosomes; (2) explore the relationship between melanosomes and """"""""secretory lysosomes."""""""" The melanosome is a member of the lysosomal lineage of organelles which most closely resembles the """"""""secretory lysosome."""""""" Whether melanosomes have subsumed all lysosomal function in melanocytes will be investigated. The potential association of the AP-3 adaptor complex with melanosomes will be determined, as will its interaction with the cytosolic tails of melanosomal membrane proteins; (3) role of the buff (bf) locus and 65 kDa melanosomal protein. A 65 kDa peripheral membrane protein in melanocytes and in cells containing """"""""secretory lysosomes"""""""" has been identified which localizes to the cytosolic face of melanosomes. Levels of this protein are altered by mutation at the buff (bf) and beige (bg) loci, both known to affect the secretory lysosomal pathway. The protein will be sequenced and its relationship to the bg gene product determined. The cDNA encoding the protein will be cloned and, if it is not a splice form of bg, its chromosomal location will be mapped in the mouse. If it maps to bf or to another coat color locus, mutational analysis will be used to determine if it is encoded at that locus. The protein's synthesis, distribution, and its interactions with other proteins will be studied to elucidate its function.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR041880-07
Application #
6171289
Study Section
General Medicine A Subcommittee 2 (GMA)
Program Officer
Moshell, Alan N
Project Start
1994-03-15
Project End
2003-06-30
Budget Start
2000-07-01
Budget End
2001-06-30
Support Year
7
Fiscal Year
2000
Total Cost
$247,102
Indirect Cost
Name
New York University
Department
Dermatology
Type
Schools of Medicine
DUNS #
City
New York
State
NY
Country
United States
Zip Code
10016
De Filippo, Elisabetta; Schiedel, Anke C; Manga, Prashiela (2017) Interaction between G Protein-Coupled Receptor 143 and Tyrosinase: Implications for Understanding Ocular Albinism Type 1. J Invest Dermatol 137:457-465
De Filippo, Elisabetta; Manga, Prashiela; Schiedel, Anke C (2017) Identification of Novel G Protein-Coupled Receptor 143 Ligands as Pharmacologic Tools for Investigating X-Linked Ocular Albinism. Invest Ophthalmol Vis Sci 58:3118-3126
Arowojolu, Omotayo A; Orlow, Seth J; Elbuluk, Nada et al. (2017) The nuclear factor (erythroid-derived 2)-like 2 (NRF2) antioxidant response promotes melanocyte viability and reduces toxicity of the vitiligo-inducing phenol monobenzone. Exp Dermatol 26:637-644
Manga, Prashiela; Elbuluk, Nada; Orlow, Seth J (2016) Recent advances in understanding vitiligo. F1000Res 5:
Murase, Daiki; Hachiya, Akira; Fullenkamp, Rachel et al. (2016) Variation in Hsp70-1A Expression Contributes to Skin Color Diversity. J Invest Dermatol 136:1681-1691
Doudican, Nicole A; Wen, Shih Ya; Mazumder, Amitabha et al. (2014) Identification of agents that promote endoplasmic reticulum stress using an assay that monitors luciferase secretion. J Biomol Screen 19:575-84
Cheng, Tsing; Orlow, Seth J; Manga, Prashiela (2013) Loss of Oca2 disrupts the unfolded protein response and increases resistance to endoplasmic reticulum stress in melanocytes. Pigment Cell Melanoma Res 26:826-34
Wang, Claire Q F; Akalu, Yemsratch T; Suarez-Farinas, Mayte et al. (2013) IL-17 and TNF synergistically modulate cytokine expression while suppressing melanogenesis: potential relevance to psoriasis. J Invest Dermatol 133:2741-2752
Toosi, Siavash; Orlow, Seth J; Manga, Prashiela (2012) Vitiligo-inducing phenols activate the unfolded protein response in melanocytes resulting in upregulation of IL6 and IL8. J Invest Dermatol 132:2601-9
Manga, Prashiela; Orlow, Seth J (2011) Informed reasoning: repositioning of nitisinone to treat oculocutaneous albinism. J Clin Invest 121:3828-31

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