I am looking for a good GFP labeled plasma membrane marker for an
immunofluorescent colocalization study, looking at subcellular
trafficking.
I have tried the Clontech pEGFP-F, and it works, although it gives a
fairly high cytoplasmic fluorescens, in addition to the rather weak plasma
membrane staining. I find it objectionable that the protein is synthesized
along a different pathway than my glycosylated integral membrane protein.
Is it correct that integral membrane proteins sometimes, or always, are
only inefficiently sorted to the plasma membrane? I suppose that must be
the reason for that Clontech uses a farnesylated protein for a marker,
rather than an integral membrane protein?
What I really would need for a marker would be a good "prototypical"
GFP-labeled glycosylated integral membrane protein, which sorts to the
plasma membrane efficiently enough to serve as a marker.
Any suggestions?
