title: Signal transduction in CHO cells stably transfected with domain-selective forms of murine ACE.
abstract: 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.
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.|Charité, Universitätsmedizin Berlin, D-13353 Berlin, Germany.
authors.forename: Xiaoou
authors.initials: X
authors.lastname: Sun
authors.affiliation: Max-Delbrück Center for Molecular Medicine, D-13125 Berlin, Germany.
authors.forename: Brit
authors.initials: B
authors.lastname: Rentzsch
authors.affiliation: Max-Delbrück Center for Molecular Medicine, D-13125 Berlin, Germany.
authors.forename: Maolian
authors.initials: M
authors.lastname: Gong
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.
authors.forename: Jenny
authors.initials: J
authors.lastname: Eichhorst
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.|Charité, Universitätsmedizin Berlin, D-13353 Berlin, Germany.
authors.forename: Kristin
authors.initials: K
authors.lastname: Pankow
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.
authors.forename: Gisela
authors.initials: G
authors.lastname: Papsdorf
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.
authors.forename: Björn
authors.initials: B
authors.lastname: Maul
authors.affiliation: Max-Delbrück Center for Molecular Medicine, D-13125 Berlin, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Bader
authors.affiliation: Leibniz-Institut für Molekulare Pharmakologie, D-13125 Berlin, Germany.
authors.forename: Wolf-Eberhard
authors.initials: WE
authors.lastname: Siems
mesh_terms: 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
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D048031:JNK Mitogen-Activated Protein Kinases; D007703:Peptidyl-Dipeptidase A