The beta isoform of protein kinase C stimulates human melanogenesis by activating tyrosinase in pigment cells.

摘要: We have investigated the role of protein kinase C (PKC) in human melanogenesis. The level PKC activity paralleled total melanin content cultured newborn melanocytes. Activation by treatment with 5 x 10(-7) M phorbol dibutyrate acutely caused a doubling tyrosinase, rate-limiting enzyme melanogenesis, known to correlate directly synthesis these cells. When was depleted 5-10% initial levels, there 40-50% parallel reduction tyrosinase activity; and regeneration associated recovery activity. By Northern blot analysis, alpha beta but not gamma isoforms were detectable Western racially determined pigment melanocytes correlated PKC-beta expression. In pigmented melanoma line (P-MM4, 20-30 ng melanin/micrograms protein)and its nonpigmented subclone (NP-MM4, undetectable melanin), PKC-alpha mRNA expressed both, whereas only P-MM4 Tyrosinase comparable both cell lines. NP-MM4 lysate incubated melanocyte contain PKC-beta, per microgram combined increased, consistent activation previously inactive origin. Moreover, cells transiently transfected cDNA increased from levels. These data show that regulates melanogenesis activating tyrosinase.