Fig. 5. Localization of syntaxin 3 in unstimulated parotid tissue. (A,C,D) Immunofluorescence of cryosections of parotid tissue have been stained with anti-syntaxin 3 (red) and either BODIPY-phallacidin to mark the actin-rich terminal web or anti-DPPIV to mark the apical plasma membrane (green). All other fluorescent images are of a single 0.1 µM layer following digital deconvolution. Closed arrowheads identify some of the syntaxin 3 foci that are concentrated beneath (on the cytoplasmic side of) the actin band or the apical plasma membrane and are found where little or no luminal space is visible. Open arrrowheads identify some of the few syntaxin 3 foci that have relocated to the luminal side of the actin band or into the DPPIV band signifying association with the apical plasma membrane. Relocated foci are generally observed where the luminal space is evident. (B) Differential interference contrast (DIC) image paired with the image in A. Bar, 10 µm.