Abstract
C-terminal truncation mutants were made to investigate the role of the C-terminus in coupling proteinase-activated receptor-2 (PAR-2) to various signalling pathways. Membrane expression of the delta15, delta34, delta43, and delta34-43 mutants was similar; however, expression of deltatail was lost, as was agonist-mediated internalisation of deltatail, delta43, and delta34-43. Additionally, trypsin and SLIGKV-stimulated [3H]IP accumulation was abrogated in cells transiently expressing delta43 or delta34-43 truncations, but remained unaffected in cells expressing delta34 or delta15. PAR-2 agonist-stimulated intracellular Ca(2+) mobilisation and PYK-2 activity were also abolished by deltatail, delta43, and delta34-43 mutants. However, trypsin-stimulated stress-activated protein kinases (SAPKs) or extracellular signal-regulated kinase (ERK) activities were unaffected by the delta34-43 mutation, although activity was abrogated following delta43 or deltatail truncations, suggesting that Ca(2+) mobilisation, PYK-2, or receptor internalisation are not requied for activation of SAPKs or ERK. These studies identify a novel sequence within the PAR-2 C-terminus essential for InsP(3) generation and PYK-2 activity but not mitogen-activated protein kinase (MAPK) activation.
Original language | English |
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Pages (from-to) | 21-29 |
Number of pages | 9 |
Journal | Cellular Signalling |
Volume | 16 |
Issue number | 1 |
Early online date | 16 Jul 2003 |
DOIs | |
Publication status | Published - Jan 2004 |
Keywords
- amino acid sequence
- animals
- COS cells
- calcium signaling
- cell membrane
- cercopithecus aethiops
- endocytosis
- focal adhesion kinase 2
- inositol phosphates
- MAP kinase signaling system
- mitogen-activated protein kinase 8
- mitogen-activated protein kinases
- mutation
- protein structure, tertiary
- protein-tyrosine kinases
- receptor, PAR-2