Figure 2.

Subcellular localization of endogenous granuphilins. INS-1 cells were grown on glass coverslips coated with laminin and poly-l-lysine. The cells were fixed with paraformaldehyde and the coverslips incubated with a rabbit polyclonal antibody directed against the N-terminus of granuphilins and an anti-insulin antibody raised in guinea pig. The subcellular distribution of granuphilins was analyzed by confocal microscopy using an Oregon-green–labeled anti-rabbit antibody. The position of secretory granules was visualized with an anti-guinea pig antibody coupled to Cy3. (A) Anti-granuphilins; (B) anti-insulin; (C) overlay between images A and B.