Articolele autorului Gertrude-Emilia Costin
Link la profilul stiintific al lui Gertrude-Emilia Costin

What is the advantage of having melanin in parts of the central nervous system (e.g. substantia nigra)?
Immortalization of mouse melanocytes carrying mutations in various pigmentation genes
Tyrosinase exacerbates dopamine and -synuclein toxicity but is not genetically associated with Parkinson’s disease

Tyrosinase is a key enzyme in the synthesis of melanin in skin and hair and has also been proposed to contribute to the formation of neuromelanin (NM). The presence of NM, which is biochemically similar to melanin in peripheral tissues, identifies groups of neurons susceptible in Parkinson's disease (PD). Whether tyrosinase is beneficial or detrimental to neurons is unclear; whilst the enzyme activity of tyrosinase generates dopamine-quinones and

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Mutations in the mouse Dct gene induce a reduction of eumelanin and an increase in the level of pheomelanin produced by melanocytes in culture

Dopachrome tautomerase (Dct) is a type I membrane protein and an important regulatory enzyme that plays a pivotal role in the biosynthesis of melanin and in the rapid metabolism of its toxic intermediates. Dct-mutant melanocytes carrying the slaty or slaty light mutations were derived from the skin of newborn congenic C57BL/6J non-agouti black mice and were used to study the effect(s) of these mutations on the intracellular trafficking of Dct and

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Modulating the intracellular composition of fatty acids affects the post-Golgi degradation of tyrosinase and elicits its retention in the endoplasmic reticulum by hyper-ubiquitination and proteasome inhibition

Proteasomes are multicatalytic proteinase complexes within cells that selectively degrade ubiquitinated proteins. We have recently demonstrated that fatty acids, major components of cell membranes, are able to regulate the proteasomal degradation of tyrosinase, a critical enzyme required for melanin biosynthesis, in contrasting manners by relative increases or decreases in the ubiquitinated tyrosinase. In the present study, we show that altering

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What is the mechanism for the pigmentation that so commonly accompanies human pregnancy?
Autoimmune diseases and vitamin D receptor Apa-I polymorphism are associated with vitiligo in a small inbred Romanian community

Vitiligo has been associated with the host's genetic profile, metabolic abnormality and immunostatus. The purpose of this study was to investigate the association of vitiligo with autoimmune diseases for 31 out of 39 subjects with vitiligo and their first-degree relatives living in a small Caucasian inbred rural community. They were compared with healthy individuals. A 2.28% prevalence of vitiligo was calculated and the presence of consanguine marriages

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Regulation of constitutive and UVR-induced skin pigmentation by melanocortin 1 receptor isoforms

Melanin synthesized by epidermal melanocytes protects the skin against UVR-induced DNA damage and skin cancer. Exposure to UVR increases the synthesis of the photoprotective eumelanin on activation of MC1R, a melanoma susceptibility gene. We studied the expression of MC1R under UVR and alpha-MSH stimulation in skin of different ethnic origins and in melanocytes of various pigmentary levels. This study identifies and characterizes a novel MC1R isoform

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. Human skin pigmentation: melanocytes modulate skin color in response to stress.

All organisms, from simple invertebrates to complex human beings, exist in different colors and patterns, which arise from the unique distribution of pigments throughout the body. Pigmentation is highly heritable, being regulated by genetic, environmental, and endocrine factors that modulate the amount, type, and distribution of melanins in the skin, hair, and eyes. In addition to its roles in camouflage, heat regulation, and cosmetic variation,

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Sialylated core 1 O-glycans influence the sorting of Pmel17/gp100 and determine its capacity to form fibrils.

Pmel17 is a melanocyte/melanoma-specific protein that is essential for the maturation of melanosomes to form mature, fibrillar, and pigmented organelles. Recently, we reported that the less glycosylated form of Pmel17 (termed iPmel17) is sorted via the plasma membrane in a manner distinct from mature Pmel17 (termed mPmel17), which is sorted directly to melanosomes. To clarify the mechanism(s) underlying the distinct processing and sorting of Pmel17,

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