[Histonet] expression pattern of GFP fusion protein in cells and mouse

[FU,DONGTAO]

Hi, all

  A researcher met a problem of GFP fusion protein expression and 
is searching an answer from the specialists here. The following is 
his question:

  I am working with an AAV vector which contains a transgene 
(dystrophin) which is fused to GFP. When I inject this vector in 
mice, and stain the tissues with antibodies raised against GFP and 
dystrophin, I only pick up GFP. It is blazing. I was surprised not 
to see colocalization given that this is a fusion protein. (I used 
the same immunostaining protocol that others have successfully 
used before me to pick up dystrophin). So, the next thing I did 
was infect 293 cells with the same vector. When I stained those 
cells, I picked up beautiful expression of dystrophin and GFP. 
They were perfectly colocalized, as expected. So, my question is, 
have you seen examples where certain epitopes are masked in one 
cellular environment and not in another? (maybe the reason that I 
cannot detect the dystrophin in the mouse tissues, but I can in 
293 cells).

  Does anyone know the possible answer of this phenomenon? Any 
thoughts will be greatly appreciated.

Ann