Tethered ligand-derived peptides of proteinase-activated receptor 3 (PAR3) activate PAR1 and PAR2 in Jurkat T cells - PubMed (original) (raw)

Desensitization of the TFRGAP-NH2 (TFR-NH2)-, SFNGGP-NH2 (SFN-NH2)-, and thrombin-mediated calcium signal by desensitization of proteinase-activated receptor 1 (PAR1), proteinase-activated receptor 2 (PAR2), or both. Jurkat cell suspensions were first exposed to receptor-desensitizing concentrations of either the PAR1-activating peptide (PAR1-AP), TFLLR-NH2 (TFL-NH2) (•, 100 µ

m

, tracings a and d), the PAR2-AP, SLIGRL-NH2 (SL-NH2) (▪, 200 µ

m

, tracings b and e), or the PAR1-2-AP, SFLLR-NH2 (SFL-NH2) (Δ, 200 µ

m

, tracings c and f). After 5 min, a test concentration of TFR-NH2 (▴, 500 µ

m

), SFN-NH2 (•, 500 or 1000 µ

m

), or thrombin (Thr) (○, 5 U/ml), was added to the cell suspensions, with a continuous recording of calcium-mediated fluorescence (E530, scale for time and fluorescence shown between tracings d and e). The calcium signal caused by TFR-NH2 (▴, 500 µ

m

), SFN-NH2 (•, 500 or 1000 µ

m

), or Thr (○, 5 U/ml), in a cell suspension that had not been previously exposed to TFL-NH2 (tracings a and d), SL-NH2 (tracings b and e), or SFL-NH2 (tracings c and f), is shown to the right of each tracing. The data are representative of experiments carried out with three separately grown suspensions of Jurkat cells.