Background
The regulation of melanogenesis has been investigated as a long-held
Conclusions
We identified a significant association between MUCL1 and threonine with melanogenesis and metastasis-related genes in melanoma cells. Our results define a novel mechanism of mucin regulation, suggesting diagnostic and preventive roles of MUCL1 in cutaneous melanoma.
Methods
The expression of mucin proteins in human skin was investigated using microarray data from the Human Protein Atlas consortium (HPA) and the Genotype-Tissue Expression consortium (GTEx) database. Mucin expression was measured at RNA and protein levels in melanoma cells. The findings were further validated and confirmed by analysis of independent experiments.
Results
We found that the several mucin proteins showed expression in human skin cells and among these, mucin-like protein 1 (MUCL1) showed the highest expression and also clear negative correlation with melanogenesis in epidermal melanocytes. We confirmed the correlations between melanogenesis and MUCL1 by revealing negative correlations in melanocytes with different melanin production, resulting from increased composition of threonine, mucin-conforming amino acid, and increased autophagy-related forkhead-box O signalling. Furthermore, threonine itself affects melanogenesis and metastatic activity in melanoma cells. Conclusions: We identified a significant association between MUCL1 and threonine with melanogenesis and metastasis-related genes in melanoma cells. Our results define a novel mechanism of mucin regulation, suggesting diagnostic and preventive roles of MUCL1 in cutaneous melanoma.