Regulation of melanosome movement by MAP kinase
2003 (English)In: Pigment Cell Research, ISSN 0893-5785, E-ISSN 1600-0749, Vol. 16, no 3, 215-221 p.Article in journal (Refereed) Published
Our objectives were to further characterize the signaling pathways in melatonin-induced aggregation in Xenopus melanophores, specifically to investigate a possible role of mitogen-activated protein kinase (MAPK). By Western blotting we found that melatonin activates MAPK, which precedes melanosome aggregation measured in a microplate reader. Activation of MAPK, tyrosine phosphorylation of a previously described 280-kDa protein, and melanosome aggregation are sensitive to PD98059, a selective inhibitor of MAPK kinase. The MAPK activation is also decreased by the adenylate cyclase stimulant forskolin. In summary, we found that MAPK is activated during melatonin-induced melanosome aggregation. Activation was decreased by an inhibitor of MAPK kinase, and by forskolin. In addition to inhibition of cyclic adenosine 3′,5′-monophosphate (cAMP), reduction in protein kinase A activity (PKA), and activation of protein phosphatase 2A, we suggest that melatonin receptors activate the MAPK cascade and tyrosine phosphorylation of the 280-kDa protein. Although the cAMP/PKA signaling pathway is the most prominent, our data suggest that simultaneous activation of the MAPK cascade is of importance to obtain a completely aggregated state. This new regulatory mechanism of organelle transport by the MAPK cascade might be important in other eukaryotic cells.
Place, publisher, year, edition, pages
2003. Vol. 16, no 3, 215-221 p.
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-26778DOI: 10.1034/j.1600-0749.2003.00048.xLocal ID: 11383OAI: oai:DiVA.org:liu-26778DiVA: diva2:247328