Until recently, the therapeutic effects of furocoumarins and furochromones plus UV-A light were thought to be due to their ability to form photoadducts with DNA in the cell nuclei; now it appears that membrane effector systems may be involved as targets. Here we show that in HeLa cells khellin at 1 and 5 microM final concentration, in combination with UV-A light, inhibits NaF-stimulated adenylyl cyclase activity and Pertussis Toxin (PT)-catalyzed ADP-ribosylation of alpha-subunits of inhibitory guanine nucleotide regulatory proteins (Gi) and increases GTPase activity. In the same experimental conditions, 8-methoxypsoralen (8-MOP), either alone or plus UV-A, does not affect adenylyl cyclase and GTPase activities. Our results suggest that in HeLa cells, through an interaction with a receptor and the mediation of Gi proteins, the adenylyl cyclase system is a target for khellin but not for 8-MOP.

DI STEFANO, A., Trabalzini, L., R., L.G., L., P., Lusini, P., & Martelli, P. (1995). Khellin, but not 8-methoxypsoralen, inhibits adenylyl cyclase system in HeLa cells. BIOCHIMICA ET BIOPHYSICA ACTA, 1269, 162-166 [10.1016/0167-4889(95)00115-9].

Khellin, but not 8-methoxypsoralen, inhibits adenylyl cyclase system in HeLa cells.

DI STEFANO, ANNA;TRABALZINI, LORENZA;LUSINI, PAOLA;MARTELLI, PAOLA
1995

Abstract

Until recently, the therapeutic effects of furocoumarins and furochromones plus UV-A light were thought to be due to their ability to form photoadducts with DNA in the cell nuclei; now it appears that membrane effector systems may be involved as targets. Here we show that in HeLa cells khellin at 1 and 5 microM final concentration, in combination with UV-A light, inhibits NaF-stimulated adenylyl cyclase activity and Pertussis Toxin (PT)-catalyzed ADP-ribosylation of alpha-subunits of inhibitory guanine nucleotide regulatory proteins (Gi) and increases GTPase activity. In the same experimental conditions, 8-methoxypsoralen (8-MOP), either alone or plus UV-A, does not affect adenylyl cyclase and GTPase activities. Our results suggest that in HeLa cells, through an interaction with a receptor and the mediation of Gi proteins, the adenylyl cyclase system is a target for khellin but not for 8-MOP.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11365/436422