Hormones

Key Biological Properties: Both Melanotan 1 and 2 stimulate melanin production, leading to increased skin pigmentation. They mimic the action of α-MSH, binding to melanocortin receptors .

Expression Patterns and Tissue Distribution: Melanotan peptides are administered via subcutaneous injections, leading to systemic distribution. They primarily target melanocortin receptors found in skin cells .

Primary Biological Functions: The primary function of Melanotan peptides is to stimulate melanogenesis, the production of melanin. This results in a tanned appearance without the need for UV exposure .

Role in Immune Responses and Pathogen Recognition: While the primary focus is on pigmentation, melanocortin receptors also play roles in immune responses and inflammation regulation .

Mechanisms with Other Molecules and Cells: Melanotan peptides bind to melanocortin receptors (MC1R, MC3R, MC4R) on melanocytes, triggering a cascade of biochemical reactions that increase melanin synthesis .

Binding Partners and Downstream Signaling Cascades: Upon binding to MC1R, Melanotan activates adenylate cyclase, increasing cAMP levels, which in turn activates protein kinase A (PKA). PKA then phosphorylates CREB, leading to increased transcription of melanogenic enzymes .

Regulatory Mechanisms: The expression and activity of Melanotan peptides are regulated at multiple levels, including transcriptional regulation by CREB and post-translational modifications that affect peptide stability and receptor binding .

Biomedical Research: Melanotan peptides are used in research to study skin pigmentation, UV protection, and related disorders .

Diagnostic Tools: Melanotan 1 is used in diagnostic tools for assessing skin disorders and photosensitivity conditions .

Therapeutic Strategies: Melanotan 1 is approved for treating erythropoietic protoporphyria, a condition causing extreme sensitivity to sunlight . Melanotan 2 is explored for its potential in treating sexual dysfunction and obesity .

Role Throughout the Life Cycle: Melanotan peptides can influence skin pigmentation from early development through aging. They may also play roles in protecting against UV-induced damage and skin cancers .