FIGURE 4.

Trafficking of SIG-EAP and SIG-SgII-EAP chimeras in PC12 cells. A, subcellular distribution of SIG-EAP and SIG-SgII-EAP. PC12 cells transfected with pCMV-SgII181-EAP or pCMV-SgII-EAP were processed for immunocytochemistry using an anti-human placental alkaline phosphatase polyclonal primary and Alexa Fluor 594-conjugated secondary antibodies and analyzed by deconvolution microscopy. B, chemiluminescence detection of secretagogue-evoked secretion of EAP chimeras. Cells transiently expressing SEAP, SIG-EAP, or SIG-SgII-EAP were exposed for 15 min to secretion medium alone (mock) or to 2 mm Ba²⁺. EAP secretion was calculated relative to total enzymatic activity present in the cells before stimulation. Total enzymatic activity is the sum of the amount released plus the amount remaining in the cells. Release of EAP is expressed either as % EAP activity secretion or relative to enzymatic activity release in the absence of secretagogue. Values are given as the means ± S.E. of triplicate determinations. †, p > 0.05; ^***, p < 0.0001 as compared with control (mock), ANOVA with Dunnett's post test. Scale bar, 5 μm.