... ABSTRACT Tropomyosins are structurally conserved α-helical coiled-coil proteins that bind along the length of filamentous actin (F-actin) in fungi and animals. Tropomyosins play essential roles in the stability of actin filaments and in regulating myosin II contractility. Despite the crucial role...

...Joyce C. M. Meiring; Nicole S. Bryce; Maria Lastra Cagigas; Aleš Benda; Renee M. Whan; Nicholas Ariotti; Robert G. Parton; Jeffrey H. Stear; Edna C. Hardeman; Peter W. Gunning ABSTRACT Co-polymers of tropomyosin and actin make up a major fraction of the actin cytoskeleton. Tropomyosin isoforms...

.... Gunning; Edna C. Hardeman ABSTRACT Many actin filaments in animal cells are co-polymers of actin and tropomyosin. In many cases, non-muscle myosin II associates with these co-polymers to establish a contractile network. However, the temporal relationship of these three proteins in the de novo assembly...

...Peter W. Gunning; Edna C. Hardeman; Pekka Lappalainen; Daniel P. Mulvihill ABSTRACT Tropomyosin (Tpm) isoforms are the master regulators of the functions of individual actin filaments in fungi and metazoans. Tpms are coiled-coil parallel dimers that form a head-to-tail polymer along the length...

... in tropomyosins has increased the compositional variety in actin filament systems. Both mechanisms dictate the subset of actin-binding proteins that interact with each filament type, leading to specialization in function. In this Hypothesis, we thus propose that different mechanisms were selected in bacteria...

... explore how research in this simple unicellular organism is providing insights into the substantial impacts these motors can have on development and viability in multicellular higher-order eukaryotes. * Author for correspondence ( [email protected] ) © 2011. 2011 Tropomyosin Fission...

...Arthur T. Coulton; Daniel A. East; Agnieszka Galinska-Rakoczy; William Lehman; Daniel P. Mulvihill Tropomyosin (Tm) is a conserved dimeric coiled-coil protein, which forms polymers that curl around actin filaments in order to regulate actomyosin function. Acetylation of the Tm N-terminal methionine...

... protein Tmod3 contributes to epithelial cell shape within confluent monolayers of polarized epithelial cells. Tmod3 localizes to lateral cell membranes in polarized epithelia of several cell types. Reduction of Tmod3 levels by shRNA leads to a loss of F-actin and tropomyosins from lateral cell membranes...

...Sawako Yamashiro; Mario Gimona; Shoichiro Ono Stabilization of actin filaments is critical for supporting actomyosin-based contractility and for maintaining stable cellular structures. Tropomyosin is a well-characterized ubiquitous actin stabilizer that inhibits ADF/cofilin-dependent actin...

...Kalomoira Skoumpla; Arthur T. Coulton; William Lehman; Michael A. Geeves; Daniel P. Mulvihill Tropomyosin is an evolutionarily conserved α-helical coiled-coil protein that promotes and maintains actin filaments. In yeast, Tropomyosin-stabilised filaments are used by molecular motors to transport...

.... Actin filaments elsewhere in the cell are long and unbranched. Results reported here show that the presence or absence of tropomyosin in these different actin-containing regions helps establish functionally distinct actin-containing compartments in the cell. Tropomyosin, an inhibitor of the Arp2/3...

...David M. Helfman; Christine Berthier; Jill Grossman; Martin Leu; Elisabeth Ehler; Evelyne Perriard; Jean-Claude Perriard ABSTRACT Vertebrate tropomyosins (TMs) are expressed from four genes, and at least 18 distinct isoforms are generated via a complex pattern of alternative RNA splicing...

...Mario Gimona; Zeev Lando; Yakov Dolginov; Joel Vandekerckhove; Ryuji Kobayashi; Apolinary Sobieszek; David M. Helfman ABSTRACT Zero-length chemical crosslinking with 1-ethyl-3-[3-(dimethyl amino)propyl]carbodiimide (EDC) indicated an association of the Ca 2+ -binding protein S100A2 with tropomyosin...

...Akiya Watakabe; Ryuji Kobayashi; David M. Helfman ABSTRACT We have identified and characterized two proteins in rat brain that bind to the neuron-specific tropomyosin isoform, TMBr3. The two proteins were identified by blot overlay assay, in which the proteins immobilized on the membrane were...

...Robert J. Pelham, Jr; Jim Jung-Ching Lin; Yuli Wang ABSTRACT Although nonmuscle tropomyosins (TM) have been implicated in various cellular functions, such as stabilization of actin filaments and possibly regulation of organelle transport, their physiological role is still poorly understood. We have...

...Mark F. Pittenger; Amy Kistler; David M. Helfman ABSTRACT The rat β-tropomyosin (TM) gene expresses two isoforms via alternative RNA splicing, namely skeletal muscle β-TM and fibroblast TM-1. The latter is also expressed in smooth muscle where it corresponds to smooth muscle β-TM. Skeletal muscle β...

...Maria S. López de Haro; Luis M. Salgado; Charles N. David; Thomas C. G. Bosch ABSTRACT A cDNA clone encoding a 253 amino acid tropomyosin was isolated from Hydra in a differential screen for headspecific genes. The Hydra tropomyosin gene, designated trop1 , is a single copy gene, lacks introns...

... to be stabilized and limited by asso- ciation with tropomyosin and the tropomyosin-binding protein, tropomodulin. Here, we use immunogold labelling followed by negative staining to specifically localize tropo- modulin, tropomyosin and actin to the sites of the central junctions in spread membrane skeletons...

... and characterize two additional components of the membrane skeleton in the rat lens: tropomyosin and the tropomyosin-binding protein tropomodulin. In the erythrocyte, tropomyosin and tropomodulin are proposed to stabilize and limit the lengths of the short actin filaments of the spectrin-actin network, thus...

... enzymes results from their differential regulation. Calcium and tropomyosin, which activate the MgATP hydrolysis and motility of vertebrate non-skeletal muscle myosin II proteins, inhibit vertebrate (brush border) myosin I. The activities and regulation of brush border myosin I provide insight...