Ceramide-1-P induces Ca super(2) super(+) mobilization in Jurkat T-cells by elevation of Ins(1,4,5)-P sub(3) and activation of a store-operated calcium channel

Sphingolipids comprise a very important class of second messengers involved in cell growth, differentiation, and apoptosis, among other different functions. Recently, these lipids have been implicated in calcium mobilization in different cell lines, including Jurkat T-lymphocytes. However, the effect of each particular sphingolipid appears to be cell-line specific. Among them, the least studied is ceramide-1-P (Cer-1-P). Here, we show that Cer-1-P increased the intracellular Ca super(2) super(+) concentration in Jurkat T-cells. Furthermore, laser-scanning confocal microscopy indicated that Ca super(2) super(+) is released from the endoplasmic reticulum. An effect on store-operated Ca super(2) super(+) channels was evidenced by whole-cell ''patch clamp'' measurements after Cer-1-P induced Ca super(2) super(+) store depletion. The mechanism of action of Cer-1-P resembles that of the Jurkat anti-TCR antibody, but differs from that of ceramide, since Cer-1-P induced an increase in Ins(1,4,5)-P sub(3).