UVB radiation increases EGF receptor mobility and trafficking in human melanocytes
(English)Manuscript (preprint) (Other academic)
For the human skin, UVB-radiation (290-320nm) is a very potent injurious agent. UV radiation is absorbed in the epidermis and reaching the melanocytes leads to proliferation via activation of growth factor reccptors. This may play a key role in the clonal expansion of melanocytes and be a critical step in carcinogenesis. We show that UVB-irradiated human epidermal melanocytes display an increased mobility of epidermal growth factor receptors (EGF-R) in the plane of the cell membrane, and that UVB affects the intracellular EGF-R transport to the nucleus. Using fluorescence photobleaching technique we show a time and dose dependent increase in the diffusion coefficient and mobile fraction of EGF-R. EGF-Rdiffuse with a low rate within the cell membrane in control cells, and the mobility increases 4-fold after single physiologic doses of UVB. Three-dimensional confocal microscopy reveals that EGF-R display a strilting difference in receptor distribution and intracellular transport before and after UVB irradiation. The EGF-Rclearly eo-localize with clathrin-coated pits within the cells. These results indicate that already single physiologic doses of UVB affect growth factor receptor mobility in cell membranes and intracellular trafficlting. This may be an important early step in the ultraviolet radiation-induced signal transduction pathway leading to cell proliferation.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-81074OAI: oai:DiVA.org:liu-81074DiVA: diva2:550200