Figure 1.

nSMase1 Ser-270 phosphorylation is induced by heat shock. (a) The Ser-270 phosphorylation of nSMase1 was induced in heat-shocked zebrafish cells. ZE cells were heat-shocked at 38 °C for 0, 15, 30, or 60 min and were then incubated at 25 °C for up to 2 h. The cell lysates were analyzed by western blotting with anti-phospho-Ser-270 nSMase1, anti-nSMase1, anti-phospho-MKK7, anti-phospho-JNK, anti-JNK, anti-phospho-c-jun, or anti-tubulin antibodies as indicated. Molecular weight markers are shown in kDa on the right. (b) Changes in the nSMase activity in response to heat-shock treatment in zebrafish cells. (c) Changes in ceramide generation in response to heat-shock treatment in zebrafish cells. The cells were heat-shocked at 38 °C for 1 h, and were then allowed to recover at 25 °C for the indicated times. The values represent the means of three independent experiments, and the error bars represent the S.D.s. *P<0.01 versus the control