You could try an N- or C-terminal fusion with Sterol response element binding factor 1(SREBF1/SREBP1) with the SCAP cleavage site deleted to prevent nuclear translocation. Both SREBF1 termini face the cytosol, while the central part of the protein integrates into the ER membrane.

Thanks Martin for the suggestion, I will look into that. 

Dear Satish,

Sec62 fusion to the N-terminus of GFP is also a possibility, we are using this way to direct proteins into the ER. Peter

Thanks Peter for the suggestion. Does the fusion result in GFP being on the cytoplasmic face, with the Sec62 insertion into the ER lumen? Am wondering if simply a Signal sequenc-TM domain fusion to GFP is suffice.

Thanks!

Yes, if the GFP is fused to the C-terminus of Sec62 that results a cytosolic localization for GFP, but Sec62 is an integral membrane protein (~40 kDa) not just a signal sequence. The Sec62’s TMs are located on the N-terminus I am not sure whether it works or not but you can try to truncate the C-terminus to reduce the size if it is a problem.