Figure 4.

Requirement of Syt 4 for NGF enhancement of Ca²⁺-evoked release in PC12 cells. (A) PC12 cells were transfected with an expression vector encoding either Syt 4 shRNA or control shRNA. After 72 h, transfected cells were lysed and subjected to immunoblot analysis with antibodies to Syt 4, Syt 1 or GAPDH. (B) PC12 cells were transfected with expression vectors encoding hGH and either a Syt 4 siRNA or a control siRNA. After 72 h, the cells were incubated for 60 min in the presence or absence of 100 ng/ml of NGF. The culture medium was then replaced with 60 mM KCl-containing salt solution for 3 min. The resulting medium was collected for detection of secreted hGH by immunoblot analysis. Results are presented as mean±s.d. from triplicate samples. Essentially, the same results were obtained in three independent experiments.