Any specific reason you want to detect it with a WB? If not it may be possible to detect it with FACS for instance. Even if you need to detect it via WB, detecting it with another method could help to make sure the protein is being produced. 

Dear Hofman, 

I need to show that my compound can inhibit p47phox translocation to the membrane. Unfortunately the FACS facility is kind of restricted here, so I am depending completely on WB.  If I could manage FACS, I'll be happy to go for that. 

Regards, 

Taufiq

For pellet solubilization, after adding RIPA buffer, I suggest add equi-volume 8M urea. Urea is often used to destroy hydrogen bonds in protein. It works well with my membrane protein, which is a GPCR. Also, the RIPA buffer you used has a stronger version for membrane protein processing, with 1% Triton X-100, 1% sodium deoxycholate, 0.1% SDS. NP-40 is relatively weak.