1986•Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)Requires access
Effects of ethanol on phosphorylation of microtubule associated proteins
Syed Ahmad, H. C. Pant
Open publisher page 0 citations
Abstract
Effects of ethanol on phosphorylation of microtubule associated protein (MAP 2) were investigated. Extract from rat brain homogenate was exposed to varying concentrations of ethanol (U-384 mM) at 37/sup 0/C for 30 minutes. Microtubules and MAPs were isolated by assembly and disassembly procedure. Proteins in these preparations were phosphorylated and phosphorylation of MAP 2 was examined by SDS-PAGE and autoradiography. Ethanol (4-24 mM) increased phosphorylation of MAP 2 as well as protein kinase activity in a dose dependent fashion. Higher concentrations of ethanol (> 24 mM) inhibited both phosphorylation of MAP 2 and protein kinase activity. In the presence of 2 ..mu..M cAMP or 24 mM ethanol, increased phosphorylation of MAP 2 was observed over control. Much higher phosphorylation of MAP 2 was observed in the presence of both cAMP (2 ..mu..M) and ethanol (24mM) than the sum of phosphorylation of MAP 2 by cAMP and ethanol separately. Kinetic studies of the influence of ethanol on MAP 2 phosphorylation reveal an increased rate of phosphorylation of MAP 2 and a decreased Km in the presence of ethanol. These studies suggest that protein kinase(s) other than cAMP dependent protein kinase are influenced by ethanol and the enzyme(s) phosphorylate at distinct sitesmore » on MAP 2.« less