@article{LangeHimmelAuerbachetal.2005, author = {Lange, Stephan and Himmel, Mirko and Auerbach, Daniel and Agarkova, Irina and Hayess, Katrin and F{\"u}rst, Dieter Oswald and Perriard, Jean-Claude and Ehler, Elisabeth}, title = {Dimerisation of myomesin : implications for the structure of the sarcomeric M-band}, issn = {0022-2836}, year = {2005}, abstract = {The sarcomeric M-band is thought to provide a link between the thick and the elastic, filament systems. So far, relatively little is known about its structural components and their three-dimensional organisation. Myomesin seems to be an essential component of the M-band, since it is expressed in all types of vertebrate striated muscle fibres investigated and can be found in its mature localisation pattern as soon as the first myofibrils are assembled. Previous work has shown that the N-terminal and central part of myomesin harbour binding sites for myosin, titin and muscle creatine kinase. Intrigued by the highly conserved domain layout of the C-terminal half, we screened for new interaction partners by yeast two-hybrid analysis. This revealed a strong interaction of myomesin with itself. This finding was confirmed by several biochemical assays. Our data suggest that myomesin can form antiparallel dimers via a binding site residing in its C-terminal domain 13. We suggest that, similar to alpha-actinin in the Z-disc, the myomesin dimers cross- link the contractile filaments in the M-band. The new and the already previously identified myomesin interaction sites are integrated into the first three-dimensional model of the sarcomeric M-band on a molecular basis. (C) 2004 Elsevier Ltd. All rights reserved}, language = {en} } @article{VorgerdvanderVenBruchertseiferetal.2005, author = {Vorgerd, M. and vanderVen, Peter F. M. and Bruchertseifer, V. and Lowe, T. and Kley, R. A. and Schr{\"o}der, Rolf and Lochmuller, H. and Himmel, Mirko and Koehler, K. and F{\"u}rst, Dieter Oswald and Huebner, A.}, title = {A mutation in the dimerization domain of filamin C causes a novel type of autosomal dominant myofibrillar myopathy}, issn = {0002-9297}, year = {2005}, abstract = {Myofibrillar myopathy (MFM) is a human disease that is characterized by focal myofibrillar destruction and pathological cytoplasmic protein aggregations. In an extended German pedigree with a novel form of MFM characterized by clinical features of a limb-girdle myopathy and morphological features of MFM, we identified a cosegregating, heterozygous nonsense mutation (8130G -> A; W2710X) in the filamin c gene ( FLNC) on chromosome 7q32.1. The mutation is the first found in FLNC and is localized in the dimerization domain of filamin c. Functional studies showed that, in the truncated mutant protein, this domain has a disturbed secondary structure that leads to the inability to dimerize properly. As a consequence of this malfunction, the muscle fibers of our patients display massive cytoplasmic aggregates containing filamin c and several Z-disk-associated and sarcolemmal proteins}, language = {en} } @article{PacholskyVakeelHimmeletal.2004, author = {Pacholsky, Dirk and Vakeel, Padmanabhan and Himmel, Mirko and Lowe, T. and Stradal, T. and Rottner, K. and F{\"u}rst, Dieter Oswald and vanderVen, Peter F. M.}, title = {Xin repeats define a novel actin-binding motif}, issn = {0021-9533}, year = {2004}, abstract = {Xin is a protein that is expressed during early developmental stages of cardiac and skeletal muscles. Immunolocalization studies indicated a peripheral localization in embryonic mouse heart, where Xin localizes with beta- catenin and N-cadherin. In adult tissues, Xin is found primarily in the intercalated discs of cardiomyocytes and the myotendinous junctions of skeletal muscle cells, both specialized attachment sites of the myofibrillar ends to the sarcolemma. A large part of the Xin protein consists of unique 16 amino acid repeats with unknown function. We have investigated the characteristics of the Xin repeats by transfection experiments and actin-binding assays and ascertained that, upon expression in cultured cells, these repeats bind to and stabilize the actin-based cytoskeleton. In vitro co- sedimentation assays with skeletal muscle actin indicated that they not only directly bind actin filaments, but also have the capability of arranging microfilaments into networks that sediment upon low-speed centrifugation. Very similar repeats were also found in Xin-repeat protein 2' (XIRP2), a novel protein that seems to be expressed mainly in striated muscles. Human XIRP2 contains 28 Xin repeats with properties identical to those of Xin. We conclude that the Xin repeats define a novel, repetitive actin-binding motif present in at least two different muscle proteins. These Xin- repeat proteins therefore constitute the first two members of a novel family of actin-binding proteins}, language = {en} } @article{HimmelVanderVenStoeckleinetal.2003, author = {Himmel, Mirko and VanderVen, Peter F. M. and St{\"o}cklein, Walter F. M. and F{\"u}rst, Dieter Oswald}, title = {The limits of promiscuity : isoform-specific dimerization of filamins}, year = {2003}, language = {en} } @phdthesis{Himmel2004, author = {Himmel, Mirko}, title = {Analyse von Protein-Protein-Wechselwirkungen und der in vivo Phosphorylierung des Sarkomerproteins Myomesin}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-5153}, school = {Universit{\"a}t Potsdam}, year = {2004}, abstract = {F{\"u}r ein tiefergehendes Verst{\"a}ndnis von Entwicklung und Funktion der quergestreiften Muskulatur ist eine Betrachtung der am Aufbau der Myofibrillen, den kontraktilen Organellen, beteiligten Proteine essentiell. Die vorliegende Arbeit besch{\"a}ftigt sich mit Myomesin, einem Protein der sarkomeren M-Bande. Zun{\"a}chst wurde die cDNA des humanen Myomesins vollst{\"a}ndig kloniert, sequenziert und nachfolgend die komplette Gr{\"o}ße der aminoterminalen Kopfdom{\"a}ne bestimmt. Es konnte gezeigt werden, daß Myomesin in vitro mit den Dom{\"a}nen 1 und 12 an Myosin bindet. Die muskelspezifische Isoform der Kreatinkinase bindet an die Dom{\"a}nen 7 und 8. Stimulations- und Inhibitionsexperimente belegen, daß Myomesin an Serin 618 in vivo durch die Proteinkinase A phosphoryliert wird und daß diese Phosphorylierung durch Aktivierung beta2-adrenerger Rezeptoren stimulierbar ist. In Muskelgewebeproben von Patienten, die an der Hypertrophen Kardiomyopathie, einer genetisch bedingten Herzmuskelkrankheit, erkrankt sind, konnte mit einem neu hergestellten phosphorylierungsabh{\"a}ngigen Antik{\"o}rper eine Verminderung der Menge phosphorylierten Myomesins nachgewiesen werden. M{\"o}gliche Ursachen werden diskutiert. Myomesin bildet Dimere, wie durch hefegenetische und biochemische Experimente gezeigt werden konnte. Die Dimerisierung von Myomesin k{\"o}nnte eine zentrale Rolle f{\"u}r den Einbau der Myosinfilamente in die naszierende Myofibrille haben. Anhand der gewonnenen Daten wurde ein verbessertes Modell der zentralen M-Bande erstellt.}, subject = {Proteine}, language = {de} } @article{WiesnerSalmikangasAuerbachetal.2000, author = {Wiesner, Sebastian and Salmikangas, Paula and Auerbach, Daniel and Himmel, Mirko and Kempa, Stefan and Hayes, Kathrin and Pacholsky, Dirk and Taivainen, Anu and Schr{\"o}der, Rolf and Carpen, Olli and F{\"u}rst, Dieter Oswald}, title = {Indications for a novel muscular dystrophy pathway : gamma-filamin, the muscle-specific filamin isoform, intgeracts with myotilin}, year = {2000}, language = {en} }