Action of trifluoperazine on physicochemical properties and the proton pump of rat brain synaptic vesicle membranes

1986 ◽  
Vol 102 (6) ◽  
pp. 1711-1714
Author(s):  
I. M. Antonikov ◽  
V. I. Mel'nik ◽  
R. N. Glebov
Keyword(s):  
Physicochemical Properties ◽  
Rat Brain ◽  
Synaptic Vesicle ◽  
Proton Pump ◽  
Vesicle Membranes

scholarly journals The proteins of synaptic vesicle membranes are affected during ageing of rat brain

2001 ◽  
Vol 33 (4) ◽  
pp. 220-225 ◽  
Author(s):  
Sae-Ra Lee ◽  
Ah-Ram Kim ◽  
Jun-Sub Kim ◽  
Jaebong Kim ◽  
Jae-Yong Lee ◽  
...  
Keyword(s):  
Rat Brain ◽  
Synaptic Vesicle ◽  
Vesicle Membranes

scholarly journals The AP-3 Complex Required for Endosomal Synaptic Vesicle Biogenesis is Associated with a Casein Kinase Ια-Like Isoform

2000 ◽  
Vol 11 (8) ◽  
pp. 2591-2604 ◽  
Author(s):  
Victor V. Faundez ◽  
Regis B. Kelly
Keyword(s):  
Synaptic Vesicle ◽  
Synaptic Vesicles ◽  
Enzymatic Reaction ◽  
Casein Kinase ◽  
Small Gtpase ◽  
Casein Kinase I ◽  
Vesicle Membranes ◽  
Vesicle Biogenesis ◽  
Hinge Domain

The formation of small vesicles is mediated by cytoplasmic coats the assembly of which is regulated by the activity of GTPases, kinases, and phosphatases. A heterotetrameric AP-3 adaptor complex has been implicated in the formation of synaptic vesicles from PC12 endosomes ( Faundez et al., 1998 ). When the small GTPase ARF1 is prevented from hydrolyzing GTP, we can reconstitute AP-3 recruitment to synaptic vesicle membranes in an assembly reaction that requires temperatures above 15°C and the presence of ATP suggesting that an enzymatic step is involved in the coat assembly. We have now found an enzymatic reaction, the phosphorylation of the AP-3 adaptor complex, that is linked with synaptic vesicle coating. Phosphorylation occurs in the β3 subunit of the complex by a kinase similar to casein kinase 1α. The kinase copurifies with neuronal-specific AP-3. In vitro, purified casein kinase I selectively phosphorylates the β3A and β3B subunit at its hinge domain. Inhibiting the kinase hinders the recruitment of AP-3 to synaptic vesicles. The same inhibitors that prevent coat assembly in vitro also inhibit the formation of synaptic vesicles in PC12 cells. The data suggest, therefore, that the mechanism of AP-3-mediated vesiculation from neuroendocrine endosomes requires the phosphorylation of the adaptor complex at a step during or after AP-3 recruitment to membranes.

scholarly journals Limited-turnover studies on proton translocation in reconstituted cytochrome c oxidase-containing vesicles

1979 ◽  
Vol 182 (1) ◽  
pp. 149-156 ◽  
Author(s):  
R P Casey ◽  
J B Chappell ◽  
A Azzi
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Proton Pump ◽  
Proton Translocation ◽  
Strong Support ◽  
Ferrocytochrome C ◽  
Vesicle Membranes ◽  
Careful Control ◽  
Hydrogen Carrier ◽  
Reconstituted System

We have investigated ferrocytochrome c-induced proton ejection from reconstituted cytochrome c oxidase-containing vesicles using careful control of the number of enzyme turnovers. Ferrocytochrome c caused the appearance of protons at the vesicle exterior, and this could be abolished by using a protonophore. In addition, its decay was dependent on the permeability of the vesicle membranes to protons and the number of turnovers of the oxidase. These observations indicate that the ejection of protons was the result of genuine translocation. The possibility of this translocation occurring via a Mitchellian loop as a result of the presence of a reduced hydrogen carrier contaminating the enzyme was considered and excluded. Proton-translocating activity in this reconstituted system depended critically on the ratio of enzyme to lipid used in the reconstitution process and we propose a rationale to account for this. We conclude that our data provide strong support for the proposal that cytochrome c oxidase acts as a proton pump and that approx. 0.9 H+ is excluded per ferrocytochrome c molecule oxidized.

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