Cellular mechanisms regulating human melanogenesis.
The major differentiated function of melanocytes is the synthesis of melanin, a pigmented heteropolymer that is synthesized in specialized cellular organelles termed melanosomes. Mature melanosomes are transferred to neighboring keratinocytes and are arranged in a supranuclear cap, protecting the DNA against incident ultraviolet light (UV) irradiation. The synthesis and distribution of melanin in the epidermis involves several steps: transcription of melanogenic proteins, melanosome biogenesis, sorting of melanogenic proteins into the melanosomes, transport of melanosomes to the tips of melanocyte dendrites and finally transfer into keratinocytes. These events are tightly regulated by a variety of paracrine and autocrine factors in response to endogenous and exogenous stimuli, principally UV irradiation.
Park
H Y
HY
Department of Dermatology, Boston University School of Medicine, 609 Albany Street, Boston, MA 02118, USA. hypark@bu.edu
Kosmadaki
M
M
Yaar
M
M
Gilchrest
B A
BA
D004249:DNA Damage; D006801:Humans; D015603:Keratinocytes / Q000378:metabolism / Q000528:radiation effects; D008543:Melanins / Q000096:biosynthesis* / Q000737:chemistry; D008544:Melanocytes / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects; D020460:Melanosomes / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects; D008954:Models, Biological; D019899:Paracrine Communication / Q000502:physiology; D015398:Signal Transduction; D016159:Tumor Suppressor Protein p53 / Q000502:physiology; D014466:Ultraviolet Rays
D008543:Melanins; D016159:Tumor Suppressor Protein p53