The effect of phorbol esters on the transport of amino acids has been evaluated in cultured human fibroblasts. The activity of the Na(+)-dependent system XAG- for anionic amino acids is selectively and markedly stimulated by phorbol esters. The effect is maximal within 15 min; it is attributable to an increase in transport maximum (Vmax) and not prevented by inhibitors of protein synthesis. The half-maximal stimulation is observed at concentrations of phorbol 12,13-dibutyrate lower than 100 nM. Prolonged incubations in the presence of 1 microM phorbol 12,13-dibutyrate lower the binding of the ligand to its receptor with a loss of the stimulatory effect on transport. The results presented indicate that the stimulation of amino acid transport through system XAG- by phorbol esters requires the activation of protein kinase C.
Phorbol esters stimulate the transport of anionic amino acids in cultured human fibroblasts / Franchi, Renata; Bussolati, Ovidio; Visigalli, Rossana; Rotoli, Bianca Maria; Rossi, Pa; Guidotti, Gg; Gazzola, Gc. - In: BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS. - ISSN 0006-291X. - 173:(1990), pp. 1304-1310.
Phorbol esters stimulate the transport of anionic amino acids in cultured human fibroblasts.
FRANCHI, Renata;BUSSOLATI, Ovidio;VISIGALLI, Rossana;ROTOLI, Bianca Maria;
1990-01-01
Abstract
The effect of phorbol esters on the transport of amino acids has been evaluated in cultured human fibroblasts. The activity of the Na(+)-dependent system XAG- for anionic amino acids is selectively and markedly stimulated by phorbol esters. The effect is maximal within 15 min; it is attributable to an increase in transport maximum (Vmax) and not prevented by inhibitors of protein synthesis. The half-maximal stimulation is observed at concentrations of phorbol 12,13-dibutyrate lower than 100 nM. Prolonged incubations in the presence of 1 microM phorbol 12,13-dibutyrate lower the binding of the ligand to its receptor with a loss of the stimulatory effect on transport. The results presented indicate that the stimulation of amino acid transport through system XAG- by phorbol esters requires the activation of protein kinase C.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.