Papers by Maria Rȩdowicz
Journal of Muscle Research and Cell Motility, Jun 20, 2022
A report on the first virtual European Muscle Conference.
Kosmos, Jul 10, 2018
W 2018 roku Instytut Biologii Doświadczalnej im. M. Nenckiego w Warszawie obchodzi 100. rocznicę ... more W 2018 roku Instytut Biologii Doświadczalnej im. M. Nenckiego w Warszawie obchodzi 100. rocznicę istnienia, a artykuł ten jest częścią specjalnego numeru poświęconego wiekowi badań przeprowadzonych w Instytucie w zakresie cytoszkieletu, ruchliwości komórek i skurczu mięśni. Artykuł opisuje historię badań oraz grupy zajmujące się tymi zagadnieniami przez dziesięciolecia. Ponadto, prezentuje wieloletni wkład naukowców z Instytutu Nenckiego w środowisko naukowe w Polsce i za granicą.
Neuromuscular Disorders, Oct 1, 2015
PubMed, 2009
Myosins, actin-dependent molecular motors are expressed in almost all eukaryotic cells where are ... more Myosins, actin-dependent molecular motors are expressed in almost all eukaryotic cells where are engaged in a panoply of cellular processes such as muscle contraction, cell migration and adhesion, intracellular trafficking, cytokinesis, endocytosis and secretion. In recent years a number of reports has been published revealing nuclear localization of myosins as well as actin and actin-binding proteins. Namely, nuclear form of myosin IC (NMI), myosin VI, myosin XVIB and myosin XVIIIB were found in nucleus. NMI and myosin VI seem to be involved in gene transcription and possibly intranuclear transport. In this paper, current knowledge on the role of myosin motors in nucleus has been presented.
Archives of Biochemistry and Biophysics, Feb 1, 2011
Amebin [formerly termed as ApABP-FI; Sobczak et al. (2007) Biochem. Cell Biol. 85] is encoded in ... more Amebin [formerly termed as ApABP-FI; Sobczak et al. (2007) Biochem. Cell Biol. 85] is encoded in Amoeba proteus by two transcripts, 2672-nt and 1125-nt. A product of the shorter transcript (termed as C-amebin), comprising C-terminal 375 amino-acid-residue fragment of amebin, has been expressed and purified as the recombinant GST-fusion protein. GST-C-amebin bound both to monomeric and filamentous actin. The binding was Ca(2+)-independent and promoted filament bundling, as revealed with the transmission electron microscopy. GST-C-amebin significantly decreased MgATPase activity of rabbit skeletal muscle acto-S1. Removal with endoproteinase ArgC of a positively charged C-terminal region of GST-amebin containing KLASMWEQ sequence abolished actin-binding and bundling as well as the ATPase-inhibitory effect of C-amebin, indicating that this protein region was involved in the interaction with actin. Microinjection of amoebae with antibody against C-terminus of amebin significantly affected amoebae morphology, disturbed cell polarization and transport of cytoplasmic granules as well as blocked migration. These data indicate that amebin may be one of key regulators of the actin-cytoskeleton dynamics and actin-dependent motility in A. proteus.
PubMed, 2009
Amoeba proteus and smaller by an order of magnitude (and evolutionary younger) Acanthamoeba caste... more Amoeba proteus and smaller by an order of magnitude (and evolutionary younger) Acanthamoeba castellanii have been for many years model cells for studies of amoeboidal (crawling) type of movement, characteristic also for some of metazoan cells such as fibroblasts, granulocytes and macrophages. Amoeboidal migration is indispensable of organization and dynamics of actin-based cytoskeleton. While there is a number of data on molecular mechanisms of motility of A. castellanii, there is very little known about bases of migration of A. proteus. Noteworthy, a large A. proteus (length approximately 600 microm) have been from over a century an object for studies on biology and physiology of cellular migration. This review describes the current knowledge on molecular aspects of force generation required for migration of these two amoebae and attempts to compare the functioning and regulation of actin cytoskeleton in these free-living unicellular species.
Biochemistry and Cell Biology, Dec 1, 2008
Recently, we found a 130-kDa myosin VI immunoanalog in amoeba, which bound to actin in an ATP-sen... more Recently, we found a 130-kDa myosin VI immunoanalog in amoeba, which bound to actin in an ATP-sensitive manner and in migrating amoebae colocalized to filamentous actin and dynamin II-containing vesicular structures. To further characterize this protein, we assessed its involvement in amoeba pinocytosis and phagocytosis. Confocal immunofluorescence microscopy and electron microscopy of immunogold-stained cells revealed that, in pinocytotic and phagocytotic amoebae, the myosin VI immunoanalog was visible throughout the cells, including pinocytotic channels and pinocytotic vesicles as well as phagosomes and emerging phagocytic cups. Blocking endogenous protein with anti-porcine myosin VI antibody (introduced into cells by means of microinjection) caused severe defects in pinocytosis and phagocytosis. In comparison with control cells, the treated amoebae formed ~75% less pinocytotic channels and phagocytosed ~65% less Tetrahymena cells. These data indicate that the myosin VI immunoanalog has an important role in pinocytosis and phagocytosis in Amoeba proteus (Pal.).
Acta Biochimica Polonica, Nov 19, 2006
The role of actin cytoskeleton functional state in glioma C6 cell morphology and calcium signalin... more The role of actin cytoskeleton functional state in glioma C6 cell morphology and calcium signaling was investigated through modification of myosin II activity by blocking Rho-associated kinase with the specific inhibitor Y-27632. Treatment of glioma C6 cells with ROCK inhibitor resulted in actin cytoskeleton reorganization and also in the changed shape and distribution of mitochondria. Changes in the distribution of ER, the main calcium store in glioma C6 cells, were not visible. The inhibition of myosin II activity influences the first phase of calcium signaling evoked by agonist, and both phases of thapsigargin-evoked calcium response. We suggest that the observed increase in Ca 2+ release from intracellular stores induced by IP 3 formation as well as inhibition of SERCA ATPase is at least in part related to severely affected mitochondria. Enhancement of capacitative calcium entry evoked by thapsigargin is probably associated with the reorganization of the acto-myosin II system. ATP-induced calcium response presents no changes in the second phase. We observed that ATP stimulation of Y-27632 pretreated cells leads to immediate morphological rearrangement of glioma C6 cells. It is a consequence of actin cytoskeleton reorganization: formation of stress fibers and relocation of phosphorylated myosin II to actin filaments. It seems that the agonist-evoked strong calcium signal may be sufficient for myosin II activation and the stress fiber organization. This is the first work showing the dependence between the functional state of the acto-myosin II system and calcium signaling stressing the reversible character of this relationship.
European Journal of Cell Biology, Sep 1, 2007
Myosins, actin-based molecular motors originally isolated from muscle tissues, are ubiquitously e... more Myosins, actin-based molecular motors originally isolated from muscle tissues, are ubiquitously expressed in all eukaryotic cells. They are involved in a panoply of cellular functions, including cell migration, intracellular trafficking, adhesion, and cytokinesis. Several unconventional myosins belonging to classes I, V, VI, VII, IX, and XVIII have been detected in myogenic cells and/or adult muscle where they seem to play important roles in muscle functioning and/or differentiation. For example, a point mutation within the myosin VI gene leads to a cardiac dysfunction, and myosin XVIIIB (expressed predominantly in striated muscle) may be involved in muscle gene transcription. This review summarizes data addressing the functioning of these unconventional myosins in muscle and/or myogenic cells.
Seminars in Cell & Developmental Biology, Aug 1, 2020
Myoblast fusion into myotubes is one of the crucial steps of skeletal muscle development (myogene... more Myoblast fusion into myotubes is one of the crucial steps of skeletal muscle development (myogenesis). The fusion is preceded by specification of a myogenic lineage (mesodermal progenitors) differentiating into myoblasts and is followed by myofiber-type specification and neuromuscular junction formation. Similarly to other processes of myogenesis, the fusion requires a very precise spatial and temporal regulation occuring both during embryonic development as well as regeneration and repair of the muscle. A plethora of genes and their products is involved in regulation of myoblast fusion and a precise multilevel interplay between them is crucial for myogenic cells to fuse. In this review, we describe both cellular events taking place during myoblast fusion (migration, adhesion, elongation, cell-cell recognition, alignment, and fusion of myoblast membranes enabling formation of myotubes) as well as recent findings on mechanisms regulating this process. Also, we present muscle disorders in humans that have been associated with defects in genes involved in regulation of myoblast fusion.
PubMed, 2001
Rho family GTP-binding proteins are known to control cellular processess associated with actin-ba... more Rho family GTP-binding proteins are known to control cellular processess associated with actin-based cytoskeleton such as cell migration, cytokinesis, endocytosis and exocytosis or muscle contraction [1]. While there is a number of data on the role of these proteins in higher Eukaryota, the studies on protozoans are practically limited to Dictyostelium that does not contain Rho-like and Cdc42-like proteins and Acanthamoeba which myosin I and actin have been found to be regulated by Rac1 and Cdc42 [2, 3]. By blocking of endogenous Rho family proteins of highly motile Amoeba proteus by the specific RhoA inhibitor, C3 transferase, and antibodies against human RhoA and Rac1 we tried to assess the in vivo effect of Rho-like proteins on amoeba morphology, locomotion and adhesion. Rho-and Rac-like proteins co-localize with Factin, and are rather evenly distributed through the cytoplasm with more pronounced accumulation in the uroid part and in the middle-anterior body region corresponding to the adhesion zone of migrating cells. Blocking of Rac-like protein(s) resulted in significant inhibition of cell migration. Microinjected amoebae flattened, strongly adhered to the glass surface and developed few wide pseudopods that seemed to be more dense than of control cells. Microinjecting with anti-RhoA antibodies led to cells rounding up and producing numerous small hyaline protrusions that were not able to attach to the surface and were relatively quickly retracting. Surprisingly the adhesion of the entire cell body was even stronger than of the control cells. Amoebae exhibited a kind of atypical, apparent imperceptible locomotion that was statistically inhibited by about 60% in comparison with control cells. After treatment with C3 transferase cells rapidly contracted and almost completely rounded up, became refractile with the granules centrally beat into a dense mass. Within several minutes amoebae detached from the surface and died. These results indicate that Rho family-based regulation of A. proteus actin cytoskeleton plays the crucial role in this protozoan functions such as cell migration, adhesion to the substratum and pseudopod formation.
Bioorganic Chemistry, Mar 1, 2019
The 1H-1,2,3-triazole-originated derivatives willardiine of were obtained by: (i) construction of... more The 1H-1,2,3-triazole-originated derivatives willardiine of were obtained by: (i) construction of the 1H-1,2,3-triazole ring in 1,3-dipolar cycloaddition of the uracil-derived azides and the carboxylate-bearing alkynes or α-acylphosphorus ylide, or (ii) N-alkylation of the uracil derivative with the 1H-1,2,3-triazole-4-carboxylate-derived mesylate. The latter method offered: (i) reproducible results, (ii) a significant reduction of amounts of auxiliary materials, (iii) reduction in wastes and (iv) reduction in a number of manual operations required for obtaining the reaction product. Compound 6a exhibited significant binding affinity to hHS1S2I ligand-binding domain of GluR2 receptor (EC50 = 2.90 µM) and decreased viability of human astrocytoma MOG-G-CCM cells in higher extent than known AMPA antagonist GYKI 52466.
International Journal of Molecular Sciences, Jun 10, 2021
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
International Journal of Molecular Sciences, Aug 28, 2020
Background: The combination effect of 5-fluorouracil (5-FU) with either CX-4945 or a new inhibito... more Background: The combination effect of 5-fluorouracil (5-FU) with either CX-4945 or a new inhibitor of protein kinase CK2, namely 14B (4,5,6,7-tetrabromo-1-(3-bromopropyl)-2-methyl-1Hbenzimidazole), on the viability of MCF-7 and triple-negative MDA-MB-231 breast cancer cell lines was studied. Methods: Combination index (CI) values were determined using an MTT-based assay and the Chou-Talalay model. The effect of the tested drug combinations on pro-apoptotic properties and cell cycle progression was examined using flow cytometry. The activation of FAK, p38 MAPK, and ERK1/2 kinases and the expression of selected pro-apoptotic markers in MDA-MB-231 cell line after the combined treatment were evaluated by the western blot method. Confocal microscopy was used to examine actin network in MDA-MB-231. Results: Our results showed that a synergistic effect (CI < 1) occurred in MDA-MB-231 after treatment with both combinations of 5-FU with 14B or CX-4945, whereas the combination of 5-FU and 14B evoked an antagonistic effect in MCF-7. We conclude that the synergistic interactions (CI < 1) observed for both the combinations of 5-FU and 14B or CX-4945 in MDA-MB-231 correlated with an activation of p38 MAPK, inhibition of FAK, increased expression of apoptogenic markers, prolongation of S-phase of cell cycle, and destabilization of actin network. Conclusions: The obtained results support the recent observation that CK2 inhibitors can improve 5-FU-based anticancer therapy and FAK kinase can be an attractive molecular target in breast cancer therapy.
Anatomical Record-advances in Integrative Anatomy and Evolutionary Biology, Aug 14, 2014
Myosin VI (MVI) is a unique unconventional myosin translocating, unlike other myosins, towards th... more Myosin VI (MVI) is a unique unconventional myosin translocating, unlike other myosins, towards the minus end of actin filaments. It is involved in numerous cellular processes such as endocytosis, intracellular trafficking, cell migration, and transcription. In mammalian skeletal muscles it localizes mainly to sarcoplasmic reticulum and is also present within the muscle nuclei and at the neuromuscular junction (Karolczak et al. Histochem Cell Biol 2013; 23:219-228). We have also shown that in denervated rat hindlimb muscle the MVI expression level is significantly increased and its localization is changed, indicating an important role of MVI in striated muscle pathology. Here, we addressed this problem by examining the distribution and expression levels of myosin VI in biopsies of skeletal muscles from patients with different myopathies. We found that, particularly in myopathies associated with fiber atrophy, the amount of MVI was enhanced and its localization in affected fibers was changed. Also, since a mutation within the human MVI gene was shown to be associated with cardiomyopathy, we assessed MVI localization and expression level in cardiac muscle using wild type and MLP(2/2) mice, a dilated cardiomyopathy model. No significant difference in MVI expression level was observed for both types of animals. MVI was found at intercalated discs and also at the sarcoplasmic reticulum. In the knockout mice, it was also present in ring-like structures surrounding the nuclei. The data indicate that in striated muscle MVI could be engaged in sarcoplasmic reticulum maintenance and/or functioning, vesicular transport, signal transmission and possibly in gene transcription.
Journal of Biological Chemistry, May 1, 1994
The actin-activated Mg(2+)-ATPase activity of filamentous Acanthamoeba myosin II is inactivated b... more The actin-activated Mg(2+)-ATPase activity of filamentous Acanthamoeba myosin II is inactivated by phosphorylation of a short non-helical tailpiece at the C-terminal end of each heavy chain even though the catalytic sites are in the N-terminal globular head. Consistent with this effect, phosphorylation at the tip of the tail alters the conformation of the head as shown by a shift in the principal site of cleavage by endoproteinase Arg-C (Ganguly, C., Martin, B., Bubb, M., and Korn, E. D. (1992) J. Biol. Chem. 267, 20905-20908). We now show that the sedimentation coefficient of monomeric phospho-myosin II is 1.3-4.6% lower than that of dephospho-myosin II, which suggests that phosphorylation produces a less compact conformation with a small increase in frictional coefficient. As shown by changes in papain digestion patterns, bound nucleotide also affects the conformation of the head region of monomeric phospho- and dephospho-myosin II, the conformation of the head region of filamentous phospho- and dephospho-myosin II, and the conformation of the C-terminal region of the tail of filamentous phospho-myosin II. Conformational differences between the dephospho- and phospho-forms of myosin II in the presence of nucleotide, as detected by susceptibility to proteolysis, therefore, appear to be greater in filaments than in monomers. These results provide additional evidence for communication between the N-terminal heads and C-terminal tails of Acanthamoeba myosin II.
Cytoskeleton, 2005
Amoeba proteus, the highly motile free-living unicellular organism, has been widely used as a mod... more Amoeba proteus, the highly motile free-living unicellular organism, has been widely used as a model to study cell motility. However, molecular mechanisms underlying its unique locomotion and intracellular actin-based-only trafficking remain poorly understood. A search for myosin motors responsible for vesicular transport in these giant cells resulted in detection of 130-kDa protein interacting with several polyclonal antibodies against different tail regions of human and chicken myosin VI. This protein was binding to actin in the ATP-dependent manner, and immunoprecipitated with anti-myosin VI antibodies. In order to characterize its possible functions in vivo, its cellular distribution and colocalization with actin filaments and dynamin II during migration and pinocytosis were examined. In migrating amoebae, myosin VI immunoanalog localized to vesicular structures, particularly within the perinuclear and sub-plasma membrane areas, and colocalized with dynamin II immunoanalog and actin filaments. The colocalization was even more evident in pinocytotic cells as proteins concentrated within pinocytotic pseudopodia. Moreover, dynamin II and myosin VI immunoanalogs cosedimented with actin filaments, and were found on the same isolated vesicles. Blocking endogenous myosin VI immunoanalog with anti-myosin VI antibodies inhibited the rate of pseudopodia protrusion (about 19% decrease) and uroidal retraction (about 28% decrease) but did not affect cell morphology and the manner of cell migration. Treatment with anti-human dynamin II antibodies led to changes in directionality of amebae migration and affected the rate of only uroidal translocation (about 30% inhibition). These results indicate that myosin VI immunoanalog is expressed in protist Amoeba proteus and may be involved in vesicle translocation and cell locomotion.
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Papers by Maria Rȩdowicz