Binding and signal transduction of the cloned vascular angiotensin II (AT1a) receptor cDNA stably expressed in Chinese hamster ovary cells

ABSTRACT To investigate the nuclear signalling pathway induced by endothelin (ET) isopeptides, we have established permanent Chinese hamster ovary (CHO) cell lines, CHO-ETA/fos-lacZ and CHO-ETB/fos-lacZ, that produce both a c-fos-β-galactosidase fusion protein and either the type A or the type B human ET receptor. These cell lines permitted a colorimetric measurement of c-fos expression, which was induced by the signal transduction system with ET receptors and ET isopeptides. We found that the ET-1-dependent c-fos expression was so efficient that it could respond to low concentrations (even a physiological concentration) of ET-1. For example, CHO-ETA/fos-lacZ and CHO-ETB/fos-lacZ responded to ET concentrations of 5×10−9m and 5×10−13m respectively. Using this highly sensitive system, the H-7 sensitive protein kinase was found to be involved in signal transduction mediated by ETA, and also partly in the ETB-mediated pathway. These lines of evidence suggest that c-fos expression occurs through at least two different pathways, depending on the concentration of ET in plasma.

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Recombinant bovine neurokinin-2 receptor stably expressed in Chinese hamster ovary cells couples to multiple signal transduction pathways.

Cell Regulation ◽

10.1091/mbc.2.10.767 ◽

1991 ◽

Vol 2 (10) ◽

pp. 767-779 ◽

Cited By ~ 25

Author(s):

H R Eistetter ◽

D J Church ◽

A Mills ◽

P P Godfrey ◽

A M Capponi ◽

...

Keyword(s):

Signal Transduction ◽

Chinese Hamster Ovary ◽

Chinese Hamster Ovary Cells ◽

Chinese Hamster ◽

Secondary Response ◽

Signal Transduction Pathways ◽

Receptor Subtypes ◽

Neurokinin A ◽

Ovary Cells ◽

Multiple Signal

Neurokinins are a family of neuropeptides with widespread distribution mediating a broad spectrum of physiological actions through three distinct receptor subtypes: NK-1, NK-2, and NK-3. We investigated some of the second messenger and cellular processes under control by the recombinant bovine NK-2 receptor stably expressed in Chinese hamster ovary cells. In this system the NK-2 receptor displays its expected pharmacological characteristics, and the physiological agonist neurokinin A stimulates several cellular responses. These include 1) transient inositol 1,4,5-trisphosphate (IP3) formation and Ca2+ mobilization, 2) increased out put of arachidonic acid and prostaglandin E2 (PGE2), 3) enhanced cyclic AMP (cAMP) generation, 4) increased de novo DNA synthesis, and 5) an induction of the "immediate early" genes c-fos and c-jun. Although NK-2 receptor-mediated IP3 formation involves activation of a pertussis toxin-insensitive G-protein, increased cAMP production is largely a secondary response and can be at least partially attributed to autocrine stimulation by endogenously generated eicosanoids, particularly PGE2. This is the first demonstration that a single recombinant neurokinin receptor subtype can regulate, either directly or indirectly, multiple signal transduction pathways and suggests several potential important mediators of neurokinin actions under physiological conditions.

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