Differential regulation of RhoA-mediated signaling by the TPalpha and TPbeta isoforms of the human thromboxane A2 receptor: independent modulation of TPalpha signaling by prostacyclin and nitric oxide.

ABSTRACT: In humans, thromboxane (TX) A(2) signals through the TPalpha and TPbeta isoforms of the TXA(2) receptor that exhibit common and distinct roles. For example, Gq/phospholipase (PL)Cbeta signaling by TPalpha is directly inhibited by the vasodilators prostacyclin and nitric oxide (NO) whereas that signaling by TPbeta is unaffected. Herein, we investigated whether TPalpha and/or TPbeta regulate G(12)/Rho activation and whether that signaling might be differentially regulated by prostacyclin and/or NO. Both TPalpha and TPbeta independently regulated RhoA activation and signaling in clonal cells over-expressing TPalpha or TPbeta and in primary human aortic smooth muscle cells (1 degrees AoSMCs). While RhoA-signaling by TPalpha was directly impaired by prostacyclin and NO through protein kinase (P

SUBMITTER: Wikstrom K 

PROVIDER: S-EPMC2681257 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature