Change of Ganglioside Accessibility at the Plasma Membrane Surface of Cultured Neurons, Following Protein Kinase C Activation
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- 作者：Paola Palestini ; Marina Pitto ; Anita Ferraretto ; Guido Tettamanti ; and Massimo Masserini
- 刊名：Biochemistry
- 出版年：1998
- 出版时间：March 3, 1998
- 年：1998
- 卷：37
- 期：9
- 页码：3143 - 3148
- 全文大小：59K
- 年卷期：v.37,no.9(March 3, 1998)
- ISSN：1520-4995
文摘
While the mechanism of signal transduction across the plasmamembrane from the exo- to theendoplasmic side has been extensively investigated, the possible returnof messages back to the outerlayer is less known. We studied the effect of protein kinase Cactivation on the ganglioside accessibilityat the exoplasmic face of intact rat cerebellar granule cells inculture, using the enzyme sialidase as theprobing molecule. Under the experimental conditions (1milliunit/mL enzyme, 2 min incubation at 37
C), only GT1b and GD1a gangliosides were partially affected by theenzyme (28.6 and 25.7% hydrolysis,respectively). After cell treatment with phorbol 12-myristate13-acetate, inducing protein kinase Cactivation, GT1b and GD1a ganglioside susceptibility to sialidase wasstrongly decreased (8.6 and 15.9%hydrolysis, respectively). A reduction of ganglioside hydrolysiswas also observed when protein kinaseC activation was induced by cell treatment for 15 min with 100 
Mglutamate. On the contrary, accessibilitydid not vary when protein kinase C translocation was not effective(either in the absence of Ca2+ in themedium or using 1 M glutamate) or when the kinase activity wasinhibited by staurosporine. Thesedata suggest that following PKC activation, a key step of inboundtransmembrane signaling, cell maydispatch outbound messages to the plasma membrane outer layer, changingthe selective recognition andcrypticity of glycolipids at the cell surface, possibly through amodulation of their segregation state.
C), only GT1b and GD1a gangliosides were partially affected by theenzyme (28.6 and 25.7% hydrolysis,respectively). After cell treatment with phorbol 12-myristate13-acetate, inducing protein kinase Cactivation, GT1b and GD1a ganglioside susceptibility to sialidase wasstrongly decreased (8.6 and 15.9%hydrolysis, respectively). A reduction of ganglioside hydrolysiswas also observed when protein kinaseC activation was induced by cell treatment for 15 min with 100 Mglutamate. On the contrary, accessibilitydid not vary when protein kinase C translocation was not effective(either in the absence of Ca2+ in themedium or using 1 M glutamate) or when the kinase activity wasinhibited by staurosporine. Thesedata suggest that following PKC activation, a key step of inboundtransmembrane signaling, cell maydispatch outbound messages to the plasma membrane outer layer, changingthe selective recognition andcrypticity of glycolipids at the cell surface, possibly through amodulation of their segregation state.