Figure 4.

hSec10-myc partially localizes at the tight junction and the levels of Sec6p and Sec8p are unchanged in hSec10 overexpressing cells. (a) Western blot by using antibody against the myc epitope tag demonstrated three hSec10 expressing clones. C, control. (b) Immunofluorescent staining by using antibody against the myc epitope tag in hSec10 overexpressing cells shows transfected hSec10p localized to the plasma membrane at the level of the tight junction (the level of the tight junction was determined by costaining with ZO-1; Lipschutz and Mostov, unpublished observations). No myc staining is evident in the control cells. (c) Western blot demonstrates equal amounts of Sec6p and Sec8p protein per microgram of total protein in Sec10 overexpressing and control cells. Ap, apical; TJ, tight junction; Bl, basolateral. Bar, 10 μm.