- 作者: Abulkhair M. Mmamoon; Rodney C. Baker; Jerry M. Farley
- 作者服務機構: Department of Pharmacology and Toxicology, University of Mississppi Medical Center, Jackson, Miss., USA
- 中文摘要: --
- 英文摘要: The muscarinic agonist, acetylcholine (ACh), stimulatesphospholipase D(PLD)activity in tracheal smooth mus-cle cells. Direct activation of protein kinase C (PKC) byphorbol-12-myristate-13-acetate (PMA) also stimulatesPLD in this tissue. Activation of ACh-induced PLD wasinhibited by the tyrosine kinase inhibitor genistein in aconcentration-dependent manner. Presently known iso-forms of PLD, PLD1 and PLD2, were identified in trachealsmooth muscle and their activation-induced phosphory-lation status studied. Both ACh and PMA increased phos-phorylation of PLD1 that was significantly blocked bygenistein or the PKC inhibitor calphostin C. PLD2 phos-phorylation was not detected in the present experiments.Western blots probed with an anti-phosphotyrosine anti-body indicate that PLD1 in this tissue is phosphorylatedon tyrosine residues after ACh or PMA stimulation. Tyro-sine phosphorylation of PLD1 was blocked by genisteinand calphostin C. No tyrosine residues were phosphory-lated on PLD2. Taken together, these results demon-strate that porcine tracheal smooth muscle celIs expressboth isoforms PLD1 and PLD2. However, on muscarinicactivation only PLD1 in this tissue is phosphorylated byPKC via a tyrosine-kinase-dependent pathway.
- 中文關鍵字: --
- 英文關鍵字: --