Dissertations / Theses on the topic 'Tyrosin'
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Eickhoff, Jan. "Untersuchungen zur Funktion der Protein-Tyrosin-Phosphatase PTPRR." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=968671373.
Müller, Jonathan Wolf. "Zelluläre und biophysikalische Studien an DYRK 3 der N-Terminus als Schlüssel zum Verständnis dieser Protein-Kinase /." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973405007.
Weiss, Andreas. "Charakterisierung der Rolle und Funktion der Protein-Tyrosin-Phosphatase Meg2." Diss., lmu, 2003. http://nbn-resolving.de/urn:nbn:de:bvb:19-10714.
Schnell, Christoph. "Lochbrennspektroskopie von Proteinen im UV Tyrosin als native optische Sonde /." [S.l.] : [s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=978991885.
Blankenfeldt, Wulf. "Röntgenstrukturanalyse der Tyrosin-Aminotransferase aus Trypanosoma cruzi bei 2.5 Å Auflösung." [S.l.] : [s.n.], 1999. http://deposit.ddb.de/cgi-bin/dokserv?idn=954338820.
Hein, Wolfgang. "Flüssigchromatographische Bestimmung von ortho-Tyrosin Nachweis der [gamma]-Bestrahlung proteinreicher Lebensmittel /." [S.l. : s.n.], 2000. http://www.sub.uni-hamburg.de/disse/298/Disse.pdf.
Moosmann, Bernd. "Strukturelle antioxidative Funktionen von Tyrosin und Tryptophan in Membranproteinen und Peptidhormonen." [S.l.] : [s.n.], 2003. http://www.diss.fu-berlin.de/2003/172/index.html.
Hackbusch, Daniel [Verfasser]. "Protein-Tyrosin-Phosphatasen (PTPs) als interventionelle Zielstrukturen der Arteriogenese / Daniel Hackbusch." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2015. http://d-nb.info/1071088882/34.
Wenta, Nikola [Verfasser]. "Einfluss der Tyrosin-Phosphorylierung auf die Selbstassoziation des Transkriptionsfaktors STAT1 / Nikola Wenta." Berlin : Freie Universität Berlin, 2009. http://d-nb.info/1023580020/34.
Tussetschläger, Stefan. "Untersuchungen zur Totalsynthese von Quinocarcin Darstellung 1,3,8-trifunktionalisierter Tetrahydrosochinoline aus m-Tyrosin." Berlin mbv, 2007. http://d-nb.info/98871583X/04.
Schmachtenberg, Anna-Juliane. "Differentielle Expression des Tyrosin-Kinoms bei akuter lymphatischer Leukämie des erwachsenen Alters." Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/19369.
Tyrosine kinases (TK) are key regulators of cellular signal transduction and affect cell cycle, cell survival, apoptosis, proliferation and differentiation. Dysregulation of TK activity contributes to the development of leukemia and other malignancies. So are 25 % of adult acute lymphoblastic leukemias (ALL) driven by the BCR-ABL1 translocation. Despite intensive therapy, the 5-year overall survival of adult patients with ALL is about 50 %. In contrast to conventional chemotherapeutic agents, the use of specific-acting TK-inhibitors offers an individualized therapeutic approach with less side-effects and a better outcome. To identify possible new therapeutic targets, a systematic survey of expression changes of the entire tyrosine kinome was carried out. A variety of different tyrosine kinases showed great changes in the expression profile of ALL-cells. Part of these expression changes can be attributed to a changed methylation profile in adult ALL. EPHA7 and PTK2 are potential markers for B-line ALL and the NTRK3, ERBB4 and ZAP70 for T-lines ALL. The interindividual varying expression of the tyrosine kinases EPHA3, EPHB3, KIT, ZAP70 and PDGFRB presumably allows a more precise risk classification. In particular, the tyrosine kinases ABL1, DDR1, EPHA7, FGFR1, ERBB4, FLT1, FLT3, FLT4, LCK, LTK, PTK2, PTK2B, PTK7, SRC, TEC and TYK2 are promising therapeutic targets, which promotes proliferation and/or inhibits apoptosis in the hematopoietic system. A proliferation promoting effect of overexpressed FLT4 could be shown for the first time. The variety of changes in the tyrosine kinase expression seems to play an important role in the development of ALL and TK could be promising new therapeutic targets.
Franck, Dominic. "Radiofluorinated cyclobutyl group for increased metabolic stability using tyrosine derivatives as model system." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2012. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-99003.
Anders, Lars. "Proteolytic processing of the receptor-like protein tyrosine phosphatase k [kappa] and deregulation in human cancer." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973410302.
Duraphe, Prashant S. [Verfasser], and Antje [Akademischer Betreuer] Gohla. "Identifizierung und Charakterisierung von AUM, einer neuen humanen Tyrosin-Phosphatase = Identification and characterization of AUM, a novel human tyrosine phosphatase / Prashant Duraphe. Betreuer: Antje Gohla." Würzburg : Universitätsbibliothek der Universität Würzburg, 2012. http://d-nb.info/101861284X/34.
Brichta, Corinna Melanie [Verfasser], and Karl Otfried [Akademischer Betreuer] Schwab. "Untersuchung von Phenylalanin und Tyrosin im Mikrodialysat von Patienten mit Phenylketonurie und Hyperphenylalaninämie." Freiburg : Universität, 2013. http://d-nb.info/1123478279/34.
Schäfer, Ellen. "Bedeutung der Protein-Tyrosin-Kinase pp60Src für die Genese der akuten myeloischen Leukämie /." Hamburg, 2007. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000252854.
Eulenburg, Volker. "Funktionelle Charakterisierung der Interaktion der Protein-Tyrosin-Phosphatase PTP-BL mit Ephrin Bs." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=964429713.
Michevec, Jennifer [Verfasser], and Peter [Akademischer Betreuer] Bayer. "Biophysikalische und funktionelle Charakterisierung humaner Tyrosin-sulfatierter Peptide / Jennifer Michevec. Betreuer: Peter Bayer." Duisburg, 2016. http://d-nb.info/110537341X/34.
Ravegnini, Gloria <1984>. "Mechanisms Contributing to Tyrosin Kinase Inhibitor Resistance in GISTs: Toward a Personalized Therapy." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amsdottorato.unibo.it/6331/.
Spankowsky, Sonja [Verfasser]. "Untersuchungen zum Effekt der Aminosäure L-Tyrosin auf die Fruchtbarkeit der Hündin / Sonja Spankowsky." Berlin : Freie Universität Berlin, 2014. http://d-nb.info/1049687728/34.
Geiseler, Anke. "Tyrosin-Kinase-abhängige Migration von B- und T-Lymphozyten durch VIP (vasoaktive Intestinal-Peptide) /." Marburg : Görich und Weiershäuser, 2004. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=012937916&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Reinheimer, Sandra. "Prognostischer Wert der 18Fluor- Ethyl-Tyrosin-Positronenemissionstomographie im Rahmen des Therapiemonitorings bei Glioblastoma multiforme." Diss., Ludwig-Maximilians-Universität München, 2014. http://nbn-resolving.de/urn:nbn:de:bvb:19-165687.
Velmeden, David [Verfasser]. "Bedeutung der Protein Tyrosin Phosphatase 1B in glatten Gefäßmuskelzellen für die Neointimabildung / David Velmeden." Mainz : Universitätsbibliothek der Johannes Gutenberg-Universität Mainz, 2021. http://d-nb.info/1238223605/34.
Gerling, Norbert. "Neuroprotektion und Aktivierung von Neurotrophin-Signaltransduktionswegen durch Hemmung von Protein-Tyrosin-Phosphatasen und durch NO-Donatoren." [S.l.] : [s.n.], 2004. http://archiv.ub.uni-marburg.de/diss/z2004/0032/.
Molavi, Tabrizi Katrin [Verfasser], Roland [Gutachter] Reinehr, and Olga [Gutachter] Sergeeva. "CD95 Ligand-induzierte CD95-Tyrosin-Nitrierung in Astrozyten / Katrin Molavi Tabrizi ; Gutachter: Roland Reinehr, Olga Sergeeva." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2017. http://d-nb.info/1128290758/34.
Ritter, Holger. "Kristallstruktur einer Phenylalanin-Ammoniak-Lyase und Kristallisation einer Tyrosin-Aminomutase sowie Komplexstrukturen der Ecto-ADP-Ribosyltransferase ART2.2." [S.l. : s.n.], 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=975656244.
Fechtner, Kerstin. "Pulmonale Genexpression im Neurotrophin-Signaltransduktionspfad TrkB-Expression am Modell der akuten und chronischen normobaren Hypoxie." Giessen VVB Laufersweiler, 2009. http://d-nb.info/996005595/04.
Feustel, Dania Anuschka. "Untersuchungen zur Expression und Regulation der CML-spezifischen Hybridkinase p210bcr/abl als Target einer potentiellen tumorspezifischen Therapie." Giessen VVB Laufersweiler, 2008. http://d-nb.info/992934605/04.
Haase, Robert [Verfasser], and Rainer [Akademischer Betreuer] Schobert. "Totalsynthese natürlicher, hochfunktionalisierter, Tyrosin-abgeleiteter 3-Acyl-Tetramsäuren - Macrocidin A und F-14329 / Robert Haase ; Betreuer: Rainer Schobert." Bayreuth : Universität Bayreuth, 2017. http://d-nb.info/1137944439/34.
Majkut, Paul Philipp [Verfasser]. "Entwicklung von Werkzeugen zur Optimierung der Funktionsanalyse Tyrosin-phosphorylierter Proteine auf Basis der zellfreien Proteinsynthese / Paul Philipp Majkut." Berlin : Freie Universität Berlin, 2013. http://d-nb.info/1044891971/34.
Wanner, Gabriele. "Untersuchungen zum molekularen Wirkmechanismus des Radioprotektors O-Phospho L-Tyrosin Wechselwirkungen von Phosphotyrosin mit Aktivierungsprozessen des epidermalen Wachstumsfaktorrezeptors /." [S.l. : s.n.], 2008. http://nbn-resolving.de/urn:nbn:de:bsz:100-opus-3081.
Knebel, Axel [Verfasser]. "Hemmung von Protein-Tyrosin-Phosphatasen als Mechanismus der Wachstumsfaktor-Rezeptor- Aktivierung durch UV, oxidativen Stress und Organometalle / Axel Knebel." Karlsruhe : KIT-Bibliothek, 1997. http://d-nb.info/1103572121/34.
Huňková, Jana. "Bestimmung der Aminosäure-Radiolyseprodukte ortho-Tyrosin und 3-(4-Hydroxyphenyl)-propionsäure als Nachweis der [gamma]-Bestrahlung [Gamma-Bestrahlung] proteinreicher Lebensmittel." [S.l. : s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=967490456.
Holzgreve, Adrien [Verfasser], and Peter [Akademischer Betreuer] Bartenstein. "Molekulare Bildgebung mittels O-(2-18F-Fluoroethyl)-L-Tyrosin Positronen-Emissions-Tomographie im Glioblastom-Mausmodell / Adrien Holzgreve ; Betreuer: Peter Bartenstein." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2018. http://d-nb.info/1176409816/34.
Reinheimer, Sandra [Verfasser], and Fougère Christian [Akademischer Betreuer] la. "Prognostischer Wert der 18Fluor- Ethyl-Tyrosin-Positronenemissionstomographie im Rahmen des Therapiemonitorings bei Glioblastoma multiforme / Sandra Reinheimer. Betreuer: Christian la Fougère." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/1048361330/34.
Hausherr, Elena [Verfasser], and Olaf [Akademischer Betreuer] Rieß. "Prävention genotoxischer und karzinogener Effekte kosmischer Strahlung durch den Radioprotektor Ortho-Phospho-L-Tyrosin / Elena Elisabeth Hausherr ; Betreuer: Olaf Rieß." Tübingen : Universitätsbibliothek Tübingen, 2015. http://d-nb.info/1197134883/34.
Unterrainer, Marcus [Verfasser]. "Die molekulare Bildgebung primärer und sekundärer Hirntumoren mittels dynamischer O-(2-18F-Fluorethyl)-L-Tyrosin Positronenemissionstomographie (18F-FET PET) / Marcus Unterrainer." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2020. http://d-nb.info/121365890X/34.
Minner, Sarah Jane Pauline. "Analyse der genomischen Loci von im Hodgkin Lymphom aberrant ausgeprägten Rezeptor-Tyrosin-Kinasen und eines Liganden mittels der Fluoreszenz-in-situ-Hybridisierung /." Frankfurt a.M, 2007. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000254016.
Schmachtenberg, Anna-Juliane [Verfasser], Kai [Gutachter] Matuschewski, Thomas [Gutachter] Burmeister, and Michael [Gutachter] Hummel. "Differentielle Expression des Tyrosin-Kinoms bei akuter lymphatischer Leukämie des erwachsenen Alters / Anna-Juliane Schmachtenberg ; Gutachter: Kai Matuschewski, Thomas Burmeister, Michael Hummel." Berlin : Humboldt-Universität zu Berlin, 2018. http://d-nb.info/1185578285/34.
Ehinger, Stefanie. "Untersuchungen zur Struktur und Funktion der Plasminogen-bindenden [alpha]-Enolase [Alpha-Enolase] aus Streptococcus pneumoniae und der Tubulin-Tyrosin-Ligase aus Sus scrofa." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972091254.
Grosskopf, Stefanie [Verfasser]. "Entwicklung und Synthese von Protein-Tyrosin-Phosphatase-Inhibitoren sowie Synthese und Validierung von SHP-2-Inhibitoren in vitro und in vivo / Stefanie Grosskopf." Berlin : Freie Universität Berlin, 2012. http://d-nb.info/1027150403/34.
Paasch, Angela [Verfasser], and H. Peter [Akademischer Betreuer] Rodemann. "Untersuchungen zur Wirkungsweise des Radioprotektors O-Phospho-L-Tyrosin auf die Zellreparatur und den Metabolismus der Zelle / Angela Paasch ; Betreuer: H. Peter Rodemann." Tübingen : Universitätsbibliothek Tübingen, 2015. http://d-nb.info/1163461857/34.
Borrelli, Cristiana. "Imprinted polymers targeting phosphorylated peptides and engineering functionalised membranes for selective recognition of riboflavin /." München : Verl. Dr. Hut, 2008. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=017126487&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Kunze, Kurt, Hendrik Niemann, Susanne Ueberlein, Renate Schulze, Hermann Ehrlich, Eike Brunner, Peter Proksch, and Karl-Heinz van Pée. "Brominated Skeletal Components of the Marine Demosponges, Aplysina cavernicola and Ianthella basta: Analytical and Biochemical Investigations." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-127045.
Stöber, Barbara. "Charakterisierung des Transportes der Aminosäuren L-[Methyl-3H]-Methionin (Met) und O-(2-[18F]fluorethyl)-L-Tyrosin (FET) in humane Lymphozyten, Makrophagen und Kolonkarzinomzellen." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=973390352.
Schulze, Wiebke [Verfasser], Niklas [Akademischer Betreuer] Engels, Jürgen [Gutachter] Wienands, and Tomas [Gutachter] Pieler. "Konstitutive Protein-Protein-Interaktionen regulieren die Aktivität der Bruton-Tyrosin-Kinase in B-Zellen / Wiebke Schulze ; Gutachter: Jürgen Wienands, Tomas Pieler ; Betreuer: Niklas Engels." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2017. http://d-nb.info/1133361579/34.
Katsakas, Dimitrios [Verfasser]. "Diagnostische Aussagekraft der intratumoralen Kinetik von O-(2-18F-Fluorethyl)-L-Tyrosin zur Beurteilung des Malignitätsgrades von zerebralen Gliomen mit der PET / Dimitrios Katsakas." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2018. http://d-nb.info/1166950506/34.
Rothe, Tino. "Anwendung mathematischer Modelle zur Vorhersage des Therapieverlaufs von CML-Patienten." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2018. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-231508.
Background Chronic myeloic leukaemia (CML) is a myeloproliferative disease, which is well suited for modelling approaches. It is characterized by the oncogenic BCR-ABL1 fusion gene originating from an inverse translocation of the chromosomes 9 and 22 leading to the Philadelphia chromosome. The result is a constitutively activated tyrosine-kinase. This is followed by an extensive proliferation of leukaemic stem cells leading to a displacement of normal haematopoesis. The molecular specificity of CML forms the basis of a highly efficient, targeted therapy by tyrosine kinase inhibitors (TKIs). TKIs can decrease the tumour burden and slow down or eventually stop progressing of the disease. Currently, in clinical applications drugs are administered for the remaining life span. Interestingly, in recent treatment cessation trials patients were stopped after two years of non-detectable tumour burden and about 50% remained without relapse. The application of computer-based modelling helps to gain access to stem cell counts being difficult to measure clinically. This forms the basis for predictions of long-term therapy outcomes. Aim of this work This work aims on identifying a suitable algorithm to efficiently identify model simulations that optimally decribe individual patient kinetics. Furthermore, the clinical usability of the new methods was investigated. Material and methods The analysed group of patients was chosen out of the German cohort of the IRIS trial to ensure comparability to former investigations. It consists of 51 individuals. The course of leukaemic burden , i. e. leukaemic vs. non-leukaemic cells on a single patient level can be described as a biphasic exponential (bi-exponential) or a piecewise linear function. As an extension to former methods described by Horn et al. (2013) all parameters are included into further method development. Additionally, an investigation was conducted whether censored data points change the functional behaviour of a bi-exponential fit based on patients’ data. According to therapy data of all patients an input parameter space for the model simulation was delimited, such that all observed patient kinetics can be mimicked by the model. This parameter space was uniformly divided into 270.400 discrete parameter combinations. The therapy simulation of each combination was conducted and described by a bi-exponential function likewise to the patients’ fit. With the help of these huge variety of in silico therapies two new methods of model parameter identification for individual patients were developed. The first one is an advanced approach based on a regression model proposed by Horn et al. (2013). The second one by comparing distances between the patients’ and the models’ bi-exponential functions (lookup table). The comparison of the distances between different therapy courses (either simulated or patients’ data) was also used to compare the quality of different methods. As an example, for one patient the stem cell kinetics from the model were analysed in more detail and checked for robustness. Such a strategy, which might build the basis for clinical applications. Results A comparison between the different bi-exponential functions with and without censored data points revealed differences especially in the area in which censoring was performed. However, for the long-term tumour burden censored data had no influence. Secondly, an investigation was performed showing the sufficiency of the pre-simulated therapy courses for the new methods, i. e. lookup-table and regression models. The lookup- table turns out to be superior to identify a therapy simulation for a unique patient, since the complexity of linear regression models lead to increased deviations between patients’ therapy courses and the simulations. Unfortunately, distinct stem cell configurations lead to similar therapy descriptions in peripheral blood, assuming the correctness of the model. As a result, the prediction of a safe treatment cessation is often widely spread. Conclusions The new developed lookup-table to identify model simulations suitable for an individual patient is highly effective and superior to other methods using regression models. The simulation of the TKI treatment using the agent-based model of Roeder und Loeffler (2002) gives easy access to therapy courses on the level of leukaemic stem cells. Unfortunately, the finding of a well fitting simulation within the peripheral blood is not enough to provide a point of safe treatment cessation, since different stem cell configurations can lead to similar therapy courses. Additionally, it is necessary to check which of the assumed therapy courses on the stem cell level is appropriate. This could be done by gathering more information from bone-marrow punctures during the course of treatment. Outlook Investigations of new data showed the important role of the immune system in CML treatment (Saussele et al. 2016; Clapp et al. 2016). This should be taken into account by improving the model of Roeder und Loeffler (2002). Additionally, data from cessation trials can be used to validate the model assumptions
Kießwetter, Birgit [Verfasser], Jörg [Akademischer Betreuer] Marienhagen, and Martin [Akademischer Betreuer] Proescholdt. "Differenzialdiagnose von niedrig- und hochmalignen Gliomen mittels O-(2-[18F]Fluorethyl-L-Tyrosin-Positronen-Emissions-Tomographie (FET-PET) / Birgit Kießwetter. Betreuer: Jörg Marienhagen ; Martin Proescholdt." Regensburg : Universitätsbibliothek Regensburg, 2012. http://d-nb.info/1025386183/34.
Duraphe, Prashant. "Identification and characterization of AUM, a novel human tyrosine phosphatase." Doctoral thesis, 2010. https://nbn-resolving.org/urn:nbn:de:bvb:20-opus-44256.
Protein phosphatases can be classified into at least three major families based on amino acid sequences at their active sites. A newly emerging phosphatase family contains the active site sequence DXDX(T/V), and belongs to the haloacid dehalogenase (HAD) superfamily of hydrolases, a ubiquitous and evolutionarily conserved enzyme family. Although the existence of 58 human HAD enzymes has been predicted by database analysis, our understanding of their biological functions remains rudimentary.By database mining amd phylogenetic analysis of human HAD phosphatases, we have found a marked increase in cell area of spreading cells, as well as accelerated cell spreading onfibronectin. Taken together, we have identified and characterized AUM as a novel member of the emerging family of aspartate-dependent protein tyrosine phosphatases. Our findings implicate AUM as an important regulator of Src-dependent cytoskeletal dynamics during cell adhesion and migration. a previously unidentified enzyme with homology to Chronophin, a cytoskeletal regulatory HAD phosphatase. We have cloned and characterized this novel enzyme and named it AUM,for actin remodeling, ubiquitously expressed, magnesium-dependent HAD phosphatase. By Northern blot, real-time PCR and Western blot analysis, we show that AUM is broadly expressed in all major human and mouse tissues with highest levels found in testis. Using immunohistochemistry, we can show that AUM is specifically expressed in maturing germ cells and that its expression peaks during spermiogenesis. To characterize the substrate preference of AUM, we have conducted an in vitro phosphatase substrate screen with 720 phosphopeptides derived from human phosphorylation sites. AUM exclusively dephosphorylates phosphotyrosine (pTyr)-containing peptides. Furthermore, only 17 pTyr peptides (~2% of all pTyr peptides investigated) acted as AUM substrates, indicating a high degree of substrate specificity. Putative AUM substrates include proteins involved in cytoskeletal dynamics and tyrosine kinase signaling.In accordance with the phosphopeptide screen, phosphatase overlay assays employing whole-cell extracts of pervanadate-treated HeLa cells show that AUM dephosphorylates only a limited number of tyrosyl-phosphorylated proteins.The role of AUM for cellular signaling was investigated in response to epidermal growth factor (EGF) stimulation in a spermatogonial cell line (GC-1 spg). The overexpression of AUM reduces, whereas the RNAi-mediated depletion of endogenous AUM increases EGF inducedtyrosine phosphorylation, including changes in the phosphorylation of the EGF receptor itself. Interestingly, in vitro kinase/phosphatase assays with purified Src and AUM indicate that AUM can activate Src, which in turn phosphorylates and inactivates AUM. Although it is at present unclear how Src and AUM regulate each other, our initial findings suggests that AUM enhances Src kinase activity independently of its phosphatase activity, whereas Src diminishes AUM phosphatase activity in a kinase dependent manner. On a cellular level, AUM-depleted cells are characterized by altered actin cytoskeletal dynamics and adhesion, as indicated by stabilized actin filaments, enlarged focal adhesions,a marked increase in cell area of spreading cells, as well as accelerated cell spreading on fibronectin. Taken together, we have identified and characterized AUM as a novel member of the emerging family of aspartate-dependent protein tyrosine phosphatases. Our findings implicate AUM as an important regulator of Src-dependent cytoskeletal dynamics during cell adhesion and migration