Beyond Tyrosinase: Understanding the molecular Insights and Functional Significance of TRP-1 and TRP-2 in Hyperpigmentation

Abstract

Introduction: Hyperpigmentation is a prevalent dermatological condition characterized by the overproduction and deposition of melanin in the skin. Tyrosinase-related proteins 1 (TRP-1) and 2 (TRP-2), also known as dopachrome tautomerase (DCT), are key players in the melanin synthesis pathway. In this review, we aim to explore the structure and role of TRP-1 and TRP-2 in hyperpigmentation. Understanding the involvement of these proteins will shed light on the underlying mechanisms and potential therapeutic strategies for hyperpigmentation disorders. Methods: A comprehensive literature search was conducted using databases such as PubMed, Scopus, and Web of Science. The search terms included "tyrosinase-related proteins 1," "TRP-1," "tyrosinase-related proteins 2," "TRP-2," "hyperpigmentation," and related keywords. Only English-language, full-text articles focusing on the structure and role of TRP-1 and TRP-2 in hyperpigmentation were included. Selected articles were assessed for their relevance to the topic and the quality of evidence presented. Results: The literature review revealed that TRP-1 and TRP-2 are critical components of the melanin synthesis pathway in melanocytes. TRP-1, a glycoprotein, is primarily involved in the maturation and stabilization of melanin. It plays a key role in eumelanin production and contributes to the brown-black pigmentation of the skin. On the other hand, TRP-2, a multifunctional enzyme, participates in the conversion of dopachrome to 5,6-dihydroxyindole-2-carboxylic acid (DHICA), a precursor of both eumelanin and pheomelanin. TRP-2 also exhibits antioxidant properties and is involved in melanosome transport and melanin deposition. Discussion: The structural characteristics of TRP-1 and TRP-2 enable their crucial functions in the melanin synthesis pathway and contribute to the complexity of hyperpigmentation. Dysregulation of TRP-1 and TRP-2 expression and activity has been linked to hyperpigmentation disorders, including melasma and post-inflammatory hyperpigmentation. Understanding the specific roles of TRP-1 and TRP-2 in hyperpigmentation may provide insights into potential therapeutic targets. Strategies to modulate the activity or expression levels of TRP-1 and TRP-2 could hold promise for the treatment of the mentioned disorders.