@article{HeindorffBlenauWalzetal.2012,
  author    = {Heindorff, Kristoffer and Blenau, Wolfgang and Walz, Bernd and Baumann, Otto},
  title     = {Characterization of a Ca2+/calmodulin-dependent AC1 adenylyl cyclase in a non-neuronal tissue, the blowfly salivary gland},
  series = {Cell calcium},
  volume    = {52},
  journal   = {Cell calcium},
  number    = {2},
  publisher = {Churchill Livingstone},
  address   = {Edinburgh},
  issn      = {0143-4160},
  doi       = {10.1016/j.ceca.2012.04.016},
  pages     = {103 -- 112},
  year      = {2012},
  abstract  = {Crosstalk between intracellular signalling pathways is a functionally important and widespread phenomenon in cell physiology across phyla. In the salivary gland of the blowfly, serotonin induces fluid secretion via parallel activation of both the InsP(3)/Ca2+ and the cAMP/PKA signalling pathways, which interact on multiple levels. We have determined the molecular identity of a link between both pathways that mediates a Ca2+-dependent rise of intracellular cAMP. Whereas hydrolysis of cAMP via phosphodiesterases is largely independent of Ca2+, cAMP synthesis by adenylyl cyclases (AC) is potentiated in a Ca2+/calmodulin (Ca2+/CaM)-dependent manner. The existence of a Ca2+/CaM-dependent AC is supported by physiological data and a molecular approach. We have cloned Cv rutabaga cDNA, encoding the first blowfly AC, and confirmed its expression in the salivary gland via reverse transcription followed by polymerase chain reaction. The putative gene product of Cv rutabaga is a Ca2+/CaM-dependent type I AC and shows highest homology to Rutabaga from Drosophila. Thus, a Ca2+/CaM-dependent AC serves as a link between the InsP(3)/Ca2+ and the cAMP/PKA signalling pathways in the salivary gland of the blowfly and might be important for the amplification and optimization of the secretory response.},
  language  = {en}
}
@article{ScheweBlenauWalz2012,
  author    = {Schewe, Bettina and Blenau, Wolfgang and Walz, Bernd},
  title     = {Intracellular pH regulation in unstimulated Calliphora salivary glands is Na+ dependent and requires V-ATPase activity},
  series = {The journal of experimental biology},
  volume    = {215},
  journal   = {The journal of experimental biology},
  number    = {8},
  publisher = {Company of Biologists Limited},
  address   = {Cambridge},
  issn      = {0022-0949},
  doi       = {10.1242/jeb.063172},
  pages     = {1337 -- 1345},
  year      = {2012},
  abstract  = {Salivary gland cells of the blowfly Calliphora vicina have a vacuolar-type H+-ATPase (V-ATPase) that lies in their apical membrane and energizes the secretion of a KCl-rich primary saliva upon stimulation with serotonin (5-hydroxytryptamine). Whether and to what extent V-ATPase contributes to intracellular pH (pH(i)) regulation in unstimulated gland cells is unknown. We used the fluorescent dye BCECF to study intracellular pH(i) regulation microfluorometrically and show that: (1) under resting conditions, the application of Na+-free physiological saline induces an intracellular alkalinization attributable to the inhibition of the activity of a Na+-dependent glutamate transporter; (2) the maintenance of resting pHi is Na+, Cl-, concanamycin A and DIDS sensitive; (3) recovery from an intracellular acid load is Na+ sensitive and requires V-ATPase activity; (4) the Na+/H+ antiporter is not involved in pHi recovery after a NH4Cl prepulse; and (5) at least one Na+-dependent transporter and the V-ATPase maintain recovery from an intracellular acid load. Thus, under resting conditions, the V-ATPase and at least one Na+-dependent transporter maintain normal pH(i) values of pH.7.5. We have also detected the presence of a Na+-dependent glutamate transporter, which seems to act as an acid loader. Despite this not being a common pH(i)-regulating transporter, its activity affects steady-state pH(i) in C. vicina salivary gland cells.},
  language  = {en}
}
@article{RoeserJordanBalfanzetal.2012,
  author    = {R{\"o}ser, Claudia and Jordan, Nadine and Balfanz, Sabine and Baumann, Arnd and Walz, Bernd and Baumann, Otto and Blenau, Wolfgang},
  title     = {Molecular and pharmacological characterization of serotonin 5-HT2 alpha and 5-HT7 receptors in the salivary glands of the blowfly calliphora vicina},
  series = {PLoS one},
  volume    = {7},
  journal   = {PLoS one},
  number    = {11},
  publisher = {PLoS},
  address   = {San Fransisco},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0049459},
  pages     = {13},
  year      = {2012},
  abstract  = {Secretion in blowfly (Calliphora vicina) salivary glands is stimulated by the biogenic amine serotonin (5-hydroxytryptamine, 5-HT), which activates both inositol 1,4,5-trisphosphate (InsP(3))/Ca2+ and cyclic adenosine 3',5'-monophosphate (cAMP) signalling pathways in the secretory cells. In order to characterize the signal-inducing 5-HT receptors, we cloned two cDNAs (Cv5-ht2 alpha, Cv5-ht7) that share high similarity with mammalian 5-HT2 and 5-HT7 receptor genes, respectively. RT-PCR demonstrated that both receptors are expressed in the salivary glands and brain. Stimulation of Cv5-ht2 alpha-transfected mammalian cells with 5-HT elevates cytosolic [Ca2+] in a dose-dependent manner (EC50 = 24 nM). In Cv5-ht7-transfected cells, 5-HT produces a dose-dependent increase in [cAMP](i) (EC50 = 4 nM). We studied the pharmacological profile for both receptors. Substances that appear to act as specific ligands of either Cv5-HT2 alpha or Cv5-HT7 in the heterologous expression system were also tested in intact blowfly salivary gland preparations. We observed that 5-methoxytryptamine (100 nM) activates only the Cv(5)-HT2 alpha receptor, 5-carboxamidotryptamine (300 nM) activates only the Cv5-HT7 receptor, and clozapine (1 mu M) antagonizes the effects of 5-HT via Cv5-HT7 in blowfly salivary glands, providing means for the selective activation of each of the two 5-HT receptor subtypes. This study represents the first comprehensive molecular and pharmacological characterization of two 5-HT receptors in the blowfly and permits the analysis of the physiological role of these receptors, even when co-expressed in cells, and of the modes of interaction between the Ca2+- and cAMP-signalling cascades. Citation: Roser C, Jordan N, Balfanz S, Baumann A, Walz B, et al. (2012) Molecular and Pharmacological Characterization of Serotonin 5-HT2a and 5-HT7 Receptors in the Salivary Glands of the Blowfly Calliphora vicina.},
  language  = {en}
}
@misc{GraefSecklerHagemannetal.2012,
  author    = {Gr{\"a}f, Ralph and Seckler, Robert and Hagemann, Alfred and D'Aprile, Iwan-Michelangelo and Schulte, Christoph and Zimmermann, Matthias and Blom, Hans and Horn-Conrad, Antje and Kampe, Heike and J{\"a}ger, Sophie and Haase, Jana and Eckardt, Barbara and Priebs-Tr{\"o}ger, Astrid and Walz, Bernd},
  title     = {Portal Wissen = Raum},
  number    = {01/2012},
  organization    = {Universit{\"a}t Potsdam, Referat f{\"u}r Presse- und {\"O}ffentlichkeitsarbeit},
  issn      = {2194-4237},
  doi       = {10.25932/publishup-44078},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-440785},
  pages     = {98},
  year      = {2012},
  abstract  = {Mit „Portal Wissen" laden wir Sie ein, die Forschung an der Universit{\"a}t Potsdam zu entdecken und in ihrer Vielfalt kennenzulernen. In der ersten Ausgabe dreht sich alles um „R{\"a}ume". R{\"a}ume, in denen geforscht wird, solche, die es zu erforschen gilt, andere, die durch Wissenschaft zug{\"a}nglich oder erschlossen werden, aber auch R{\"a}ume, die Wissenschaft braucht, um sich entfalten zu k{\"o}nnen. Forschung vermisst R{\"a}ume: „Wissenschaft wird von Menschen gemacht", schrieb der Physiker Werner Heisenberg. Umgekehrt l{\"a}sst sich sagen: Wissenschaft macht Menschen, widmet sich ihnen, beeinflusst sie. Dieser Beziehung ist „Portal Wissen" nachgegangen. Wir haben Wissenschaftler getroffen, sie gefragt, wie aus ihren Fragen Projekte entstehen, haben sie auf dem oft verschlungenen Weg zum Ziel begleitet. Ein besonderes Augenmerk dieses Heftes gilt den „Kulturellen Begegnungsr{\"a}umen", denen ein eigener Profilbereich der Forschung an der Universit{\"a}t Potsdam gewidmet ist. Forschung hat R{\"a}ume: Labore, Bibliotheken, Gew{\"a}chsh{\"a}user oder Archive - hier ist Wissenschaft zu Liebe Leserinnen und Leser, Hause. All diese Orte sind so einzigartig wie die Wissenschaftler, die in ihnen arbeiten, oder die Untersuchungen, die hier stattfinden. Erst die Vision davon, wie ein Problem zu l{\"o}sen ist, macht aus einfachen Zimmern „Laborr{\"a}ume". Wir haben ihre T{\"u}ren ge{\"o}ffnet, um zu zeigen, was - und wer - sich dahinter befindet. Forschung er{\"o}ffnet R{\"a}ume: Wenn Wissenschaft erfolgreich ist, bewegt sie uns, bringt uns voran. Auf dem Weg einer wissenschaftlichen Erkenntnis aus dem Labor in den Alltag stehen mitunter H{\"u}rden, die meist nicht auf den ersten Blick zu erkennen sind. Auf jeden Fall aber ist ihre Anwendung erster Ausgangspunkt von Wissenschaft, Antrieb und Motivation jedes Forschers. „Portal Wissen" zeigt, welche „Praxisr{\"a}ume" sich aus der {\"U}bersetzung von Forschungsresultaten ergeben. Dort, wo wir es unbedingt erwarten, und dort, wo vielleicht nicht. Forschung erschließt R{\"a}ume: Bei Expeditionen, Feldversuchen und Exkursionen wird nahezu jede Umgebung zum mobilen Labor. So er{\"o}ffnet Wissenschaft Zug{\"a}nge auch zu Orten, die auf vielfach andere Weise verschlossen oder unzug{\"a}nglich scheinen. Wir haben uns in Forscher- Reisetaschen gemogelt, um bei Entdeckungsreisen dabei zu sein, die weit weg - vor allem nach Afrika - f{\"u}hren. Zugleich haben wir beobachtet, wie „Entwicklungsr{\"a}ume" sich auch von Potsdam aus erschließen lassen oder zumindest ihre Vermessung in Potsdam beginnen kann. Forschung braucht R{\"a}ume: Wissenschaft hat zwei Geschlechter, endlich. Noch nie waren so viele Frauen in der Forschung t{\"a}tig wie derzeit. Ein Grund zum Ausruhen ist dies gleichwohl nicht. Deutschlandweit ist aktuell nur jede f{\"u}nfte Professur von einer Frau besetzt. „Portal Wissen" schaut, welche „Entwicklungsr{\"a}ume" Frauen sich in der Wissenschaft, aber auch dar{\"u}ber hinaus geschaffen haben. Und wo sie ihnen verwehrt werden. Wir w{\"u}nschen Ihnen eine anregende Lekt{\"u}re und dass auch Sie einen Raum finden, der Sie inspiriert. Prof. Dr. Robert Seckler Vizepr{\"a}sident f{\"u}r Forschung und wissenschaftlichen Nachwuchs},
  language  = {de}
}
@misc{BaumannWalz2012,
  author    = {Baumann, Otto and Walz, Bernd},
  title     = {The blowfly salivary gland - A model system for analyzing the regulation of plasma membrane V-ATPase},
  series = {Journal of insect physiology},
  volume    = {58},
  journal   = {Journal of insect physiology},
  number    = {4},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0022-1910},
  doi       = {10.1016/j.jinsphys.2011.11.015},
  pages     = {450 -- 458},
  year      = {2012},
  abstract  = {Vacuolar H+-ATPases (V-ATPases) are heteromultimeric proteins that use the energy of ATP hydrolysis for the electrogenic transport of protons across membranes. They are common to all eukaryotic cells and are located in the plasma membrane or in membranes of acid organelles. In many insect epithelia, V-ATPase molecules reside in large numbers in the apical plasma membrane and create an electrochemical proton gradient that is used for the acidification or alkalinization of the extracellular space, the secretion or reabsorption of ions and fluids, the import of nutrients, and diverse other cellular activities. Here, we summarize our results on the functions and regulation of V-ATPase in the tubular salivary gland of the blowfly Calliphora vicina. In this gland, V-ATPase activity energizes the secretion of a KCl-rich saliva in response to the neurohormone serotonin (5-HT). Because of particular morphological and physiological features, the blowfly salivary glands are a superior and exemplary system for the analysis of the intracellular signaling pathways and mechanisms that modulate V-ATPase activity and solute transport in an insect epithelium.},
  language  = {en}
}