vacoular or plasma membrane protein?

[Dr Engelbert Buxbaum]

In article <mailman.476.1300830859.20886.methods from net.bio.net>, 
emad.albarouki from landw.uni-halle.de says...
> 
> Hello everybody,
> 
> I have a question concerning a plasma membrane protein, which have been
> expected using different proteomic software to be localized on the plasma
> membrane.
> 
> After tagging with gfp it looks to be localized in more than 80%  on vesicle
> structures which we assumed to be vacuoles. 
> 
> Is it possible to be a bifunctional protein such as transporter on plasma
> membrane and vacuole? or that could be an artifact of gfp fusion process?
> 
> Is there any programs or software can discriminate between both
> compartment's proteins? 

Software can make predictions, but those have to be checked by 
experiment. Homogenisation of the cells and fractionisation on a sucrose 
gradient in an ultracentrifuge would be a classical way of doing it, or 
immunofluorescence microscopy.