UV-induced expression of key component of the tanning process, the POMC and MC1R genes, is dependent on the p-38-activated upstream stimulating factor-1 (USF-1)
Résumé
Protection against UV-mediated DNA damage and the onset of oncogenesis is afforded by the tanning response in which UV irradiation triggers melanocytes to increase production of melanin that is then transferred to keratinocytes. A key component of the tanning process is the UV-mediated induction of the pro-opiomelanocortin (POMC) and MC1R genes encoding the alpha-melanocyte-stimulating hormone and its receptor, respectively, which play a crucial role in pigmentation by regulating the intracellular levels of cAMP. How these genes are regulated in response to UV irradiation is not known. Here we have shown that UV-induced activation of the POMC and MC1R promoters is mediated by p38 stress-activated kinase signaling to the transcription factor, upstream stimulating factor-1 (USF-1). Importantly, melanocytes derived from USF-1 -/- mice exhibit a defective UV response and fail to activate POMC and MC1R expression in response to UV irradiation. The results define USF-1 as a critical UV-responsive activator of genes implicated in protection from solar radiation.
Mots clés
Complementary
DNA-Binding Proteins
Gene Expression Regulation
Genes
Reporter
Humans
Luciferases
Melanins
Melanocytes
Mice
Models
Biological
p38 Mitogen-Activated Protein Kinases
Pigmentation
Promoter Regions
Genetic
Pro-Opiomelanocortin
Receptors
Pituitary Hormone
RNA
Signal Transduction
Spectrophotometry
Sunlight
Time Factors
Transcription Factors
Transcription
Transfection
Transgenes
Ultraviolet Rays
Upstream Stimulatory Factors
Amino Acid Motifs
Animals
Blotting
Western
Cell Line
Tumor
Chromatin Immunoprecipitation
DNA
DNA Damage