Two isoforms of prostaglandin EP3 receptor exhibiting constitutive activity and agonist-dependent activity in Rho-mediated stress fiber formation
Hasegawa, H.; Negishi, M.; Katoh, H.; Ichikawa, A.
Biochemical and Biophysical Research Communications 234(3): 631-636
1997
ISSN/ISBN: 0006-291X
PMID: 9175765
DOI: 10.1006/bbrc.1997.6655
Accession: 009684085
We have cloned two isoforms of the mouse prostaglandin E receptor EP3 subtype, EP3alpha and EP3beta, with different carboxyl-terminal tails, produced through alternative splicing. To determine the functional differences between the two isoforms, we examined the role of the isoforms in regulation of the actin cytoskeleton using Mardin-Darby canine kidney cells expressing these isoforms. The EP3alpha isoform constitutively induced stress fiber formation, independent of an agonist, while the EP3beta isoform agonist-dependently induced stress fiber formation. Pertussis toxin did not prevent stress fiber formation. This signaling pathway is mediated by Rho, because C3 transferase microinjection inhibited stress fiber formation. Therefore, the physiological significance of these isoforms of the EP3 receptor may lie in their different agonist dependency in Rho-mediated stress fiber formation via a pertussis toxin-insensitive G protein.