Signal transduction in CHO cells stably transfected with domain-selective forms of murine ACE.
Membrane-bound human angiotensin-converting enzyme (ACE) has been reported to initiate intracellular signaling after interaction with substrates or inhibitors. Somatic ACE is known to contain two distinct, extracellular catalytic centers. We analyzed the signal transduction mechanisms in cells transfected with different forms of murine ACE (mACE) and investigated whether the two domains are similarly involved in these processes. For this purpose, CHO cells were stably transfected with mACE or with its domain-selective mutants. In addition to these modified cellular models, human umbilical vein endothelial cells were used in this study. Signal transduction molecules such as JNK and c-Jun were analyzed after activation of cells with several ACE substrates and inhibitors. ACE-targeting compounds such as substrates, inhibitors, or even the ACE product angiotensin-II induce in mACE-expressing cells a signal transduction response. These processes are also evoked by partially inactivated forms of mACE and finally result in an enhanced cyclooxygenase-2 transcription. Surprisingly, the membrane-bound ACE activity is also influenced by ACE-targeted interventions. Our data suggest that the two catalytic domains of mACE do not function independently but that the signal transduction is influenced by negative cooperativity of the two catalytic domains. This study underlines that ACE indeed has receptor-like properties which occur in a species-specific manner.
Sun
Xiaoou
X
Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.|Charité, Universitätsmedizin Berlin, D-13353 Berlin, Germany.
Rentzsch
Brit
B
Max-Delbrück Center for Molecular Medicine, D-13125 Berlin, Germany.
Gong
Maolian
M
Max-Delbrück Center for Molecular Medicine, D-13125 Berlin, Germany.
Eichhorst
Jenny
J
Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.
Pankow
Kristin
K
Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.|Charité, Universitätsmedizin Berlin, D-13353 Berlin, Germany.
Papsdorf
Gisela
G
Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.
Maul
Björn
B
Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.
Bader
Michael
M
Max-Delbrück Center for Molecular Medicine, D-13125 Berlin, Germany.
Siems
Wolf-Eberhard
WE
Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.
D000494:Allosteric Regulation; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D055162:Biocatalysis; D016466:CHO Cells; D020134:Catalytic Domain / Q000235:genetics; D002478:Cells, Cultured; D006224:Cricetinae; D003412:Cricetulus; D042783:Endothelial Cells / Q000378:metabolism; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000032:analysis / Q000037:antagonists & inhibitors / Q000378:metabolism; D051379:Mice; D009154:Mutation; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D014162:Transfection
D000806:Angiotensin-Converting Enzyme Inhibitors; D048031:JNK Mitogen-Activated Protein Kinases; D007703:Peptidyl-Dipeptidase A