Fig 4. S100A6 is necessary for the Ca²⁺-dependent nuclear translocation of CacyBP/SIP.

(A) The mRNA levels of S100A6 were measured by qRT-PCR. Total S100A6 mRNA in cells was examined by qRT-PCR. Student’s t-test, error bars represent the mean±s.d., **P<0.01, ***P<0.001, (S100A1si-1), (S100A1si-2) and (S100A1si-3) vs. SW480. (B) The protein levels of S100A6 were measured by western blot analysis. Data are representative immunoblots of three independent assays. The intensities were compared by one-way analysis of variance and Student’s t-test, error bars represent the mean±s.d., **P<0.01. (C) S100A6 knockdown abolished the Ca²⁺-dependent nuclear translocation of CacyBP/SIP. Cells were treated with 5 μmol/L of ionomycin plus S100A6si for 30 min, followed by immunostaining using anti-CacyBP/SIP, and were imaged with confocal microscopy. SW480 cells were fixed and immunostained using CacyBP/SIP MAb (panels a, d, and g), and nuclei were labeled with DAPI (panels b, e, and h). The merged images are shown in panels c, f, and i. The scale bar represents 50 μm.