title: Forskolin and camptothecin induce a 30 kDa protein associated with melatonin production in Y79 human retinoblastoma cells.
abstract: The synthesis of melatonin in Xenopus retinas, chick and quail retinal cell cultures, and Y79 human retinoblastoma cells is stimulated by cAMP through a protein synthesis-dependent mechanism. In Y79 retinoblastoma cells, combined treatment with the RNA synthesis inhibitor camptothecin and agents that elevate cAMP, such as forskolin, causes a synergistic elevation of melatonin. Using two-dimensional gel analysis we have identified a 30 kDa cytosolic protein (p30) whose radiolabeling was consistently increased in parallel with increases in arylalkylamine N-acetyltransferase activity and melatonin production that were induced by forskolin and/or camptothecin. Pulse-chase experiments suggest that the elevation in radiolabeling of p30 is due to increased synthesis. Three candidate proteins found in the mammalian pineal, protein 14-3-3, malate dehydrogenase, and recoverin, do not comigrate with p30.
authors: Department of Neurobiology and Physiology, Northwestern University, Evanston, Illinois 60208-3520.
authors: J L
authors: JL
authors: Janavs
authors: J C
authors: JC
authors: Florez
authors: M E
authors: ME
authors: Pierce
authors: J S
authors: JS
authors: Takahashi
mesh_terms: D002166:Camptothecin / Q000494:pharmacology*; D005576:Colforsin / Q000494:pharmacology*; D006801:Humans; D015151:Immunoblotting; D008550:Melatonin / Q000096:biosynthesis*; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000737:chemistry / Q000378:metabolism*; D012175:Retinoblastoma / Q000378:metabolism* / Q000473:pathology; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D009363:Neoplasm Proteins; D005576:Colforsin; D008550:Melatonin; D002166:Camptothecin