Vinculin Migrates to the Cell Membrane of Melanocytes After UVB Irradiation

Abstract

Melanocytes increase melanin production upon exposure to ultraviolet rays (UV) as a defense mechanism. Melanin synthesis in melanocytes is regulated by bioactive factors produced and secreted by keratinocytes. In addition, melanocytes transfer biosynthesized melanin to keratinocytes, causing skin pigmentation. During the pigmentation process, melanocytes communicate with surrounding cells. However, the molecules involved in this cell-to-cell communication, particularly in melanocytes, are poorly understood. In this study, we focused on changes in cell membrane protein expression following exposure of melanocytes to UV irradiation. After mouse melanoma B16 cells were exposed to UV irradiation, alterations in the expression of cell membrane proteins were analyzed using peptide mass fingerprinting. We identified the membrane protein vinculin from proteins with enhanced expression. Western blot results confirmed UV exposure increased vinculin in cell membranes. In contrast, there was no change in vinculin levels in whole cell extracts. Furthermore, we observed no variation in mRNA expression levels using real time PCR. Melanocytes exposed to UV enhanced vinculin migration to cell membranes without altering expression levels. We suggest vinculin involved in the cellular responses of melanocytes and keratinocytes.