Concomitant and hormonally regulated expression of trp genes in bovine aortic endothelial cells.

Recent findings have suggested that the vertebrate trp family of channel proteins is the structural basis for Ca2+ influx through the capacitative calcium entry (CCE) pathway. We have discerned, in bovine aortic endothelial cells, the concomitant expression of four such vertebrate genes: trp-1 (two splice variants), trp-3, trp-4 and trp-5. Exogenous hormones rendered dynamic effects on the transcript levels of these genes. Most notably, beta-estradiol significantly down-regulated trp-4 while trans-retinoic acid dramatically up-regulated trp-5; yet these hormones rendered little change in CCE. These findings suggest that the extent of a given trp channel's participation in CCE is not reflected in alterations of its transcript level.