Referenced in: none

Automatically associated channels: TRP , TRPA , TRPA1

Title: UV light phototransduction depolarizes human melanocytes.

Authors: Nicholas W Bellono, Elena Oancea

Journal, date & volume: Channels (Austin), 2013 Jun 13 , 7,

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/23764911

Abstract
Exposure of human skin to low doses of solar UV radiation (UVR) causes increased pigmentation, while chronic exposure is a powerful risk factor for skin cancers. The mechanisms mediating UVR detection in skin, however, remain poorly understood. Our recent studies revealed that UVR activates a retinal-dependent G protein-coupled signaling pathway in melanocytes. This phototransduction pathway leads to the activation of transient receptor potential A1 (TRPA1) ion channels, elevation of intracellular calcium (Ca( 2+)) and rapid increase in cellular melanin content. Here we report that physiological doses of solar-like UVR elicit a retinal-dependent membrane depolarization in human epidermal melanocytes. This transient depolarization correlates with delayed inactivation time of the UVR-evoked photocurrent and with sustained Ca( 2+) responses required for early melanin synthesis. Thus, the cellular depolarization induced by UVR phototransduction in melanocytes is likely to be a critical signaling mechanism necessary for the protective response represented by increased melanin content.