• Journal of Microbiology and Biotechnology
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• v.25 no.3
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• pp.307-316
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• 2015

Beginning from the recognition of FtsZ as a bacterial tubulin homolog in the early 1990s, many bacterial cytoskeletal elements have been identified, including homologs to the major eukaryotic cytoskeletal elements (tubulin, actin, and intermediate filament) and the elements unique in prokaryotes (ParA/MinD family and bactofilins). The discovery and functional characterization of the bacterial cytoskeleton have revolutionized our understanding of bacterial cells, revealing their elaborate and dynamic subcellular organization. As in eukaryotic systems, the bacterial cytoskeleton participates in cell division, cell morphogenesis, DNA segregation, and other important cellular processes. However, in accordance with the vast difference between bacterial and eukaryotic cells, many bacterial cytoskeletal proteins play distinct roles from their eukaryotic counterparts; for example, control of cell wall synthesis for cell division and morphogenesis. This review is aimed at providing an overview of the bacterial cytoskeleton, and discussing the roles and assembly dynamics of bacterial cytoskeletal proteins in more detail in relation to their most widely conserved functions, DNA segregation and coordination of cell wall synthesis.

• Archives of Pharmacal Research
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• v.23 no.6
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• pp.535-547
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• 2000

Recent findings indicate that mechanical strain (deformation) exerted by the extracellular matrix modulates activation of airway smooth muscle cells. Furthermore, cytoskeletal organization in airway smooth muscle appears to be dynamic, and subject to modulation by receptor activation and mechanical strain. Mechanosensitive modulation of crossbridge activation and cytoskeletal organization may represent intracellular feedback mechanisms that limit the shortening of airway smooth muscle during bronchoconstriction. Recent findings suggest that receptor-mediated signal transduction is the primary target of mechanosensitive modulation. Mechanical strain appears to regulate the number of functional G-proteins and/or phospholipase C enzymes in the cell membrane possibly by membrane trafficking and/or protein translocation. Dense plaques, membrane structures analogous to focal adhesions, appear to be the primary target of cytoskeletal regulation. Mechanical strain and receptor-binding appear to regulate the assembly and phosphorylation of dense plaque proteins in airway smooth muscle cells. Understanding these mechanisms may reveal new pharmacological targets for control1ing airway resistance in airway diseases.

• Journal of Life Science
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• v.9 no.2
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• pp.34-39
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• 1999

The postsynaptic density (PSD) is a cytoskeletal specialization that is involved in the regulation of synaptic signal transduction. Mainly due to the hydrophobic nature of the PSD proteins, characterization of this intriguing structure at the molecular level has been very intractable until early 1990s. However, recent development in protein microchemistry and molecular cloning techniques allowed identification and characterization of the PSD proteins. As expected, cytoskeletal proteins constitute major components of the PSD. Other major PSD proteins have been identified by protein sequencing, and their genes were used to fish out associating proteins by yeast two-hybrid system expanding our knowledge on the molecular structure of the PSD significantly. In this review, I summarize proteins that are so far identified focusing on the glutamatergic synapses.

• The Korean Journal of Zoology
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• v.36 no.3
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• pp.342-346
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• 1993

The protein level of cytoskeletons in cultured myoblasts was found to gradually decrease during the course of myogenesis. This decrease, however, could be prevented by treatiag the ceils with calpeptin (benzyloxycarbonyl-Leu-nLeu-H), a cell penetrating inhibitor of calpain. In contrast, E-64, which also is a potent inhibitor of calpain but can not be transported into the cells, showed little or no effect. In addition, the treatment of calpeptin was found to stabilize a number of specific cytoskeletal proteins from degradation but without any effect on the pattern of total cells proteins. Furthermore, calpeptin, but not E-64, blocked myoblast fusion in a dose-dependent manner. These results suggest that calpain is responsible for the myogenic time-dependent loss of cytoskeletal proteins and that the degradative process is associated with myoblast fusion. These results also suggest that the differential effects of the calpain inhibitors depend on the permeabIlity of the drugs across the cell membrane.

• Parasites, Hosts and Diseases
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• v.39 no.1
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• pp.13-21
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• 2001

Pneumocystis carinii causes serious pulmonary infection in immuno-suppressed patients. This study was undertaken to observe the cytoskeletal proteins of P. carinii by immune-electron microscopy. P. carinii infection was experimentally induced by immunosuppression of Sprague-Dawley rats for seven weeks, and their lungs were used for the observations of this study. The gold particles localized actin, tropomyosin, and tubulin. The actin was irregularly scattered in the cytoplasm of the trophic forms but was much more concentrated in the inner space of the cell wall of the cystic forms called the inner electron-lucent layer No significant amount of tropomyosin was observed in either trophic forms or cystic forms. The tubulin was distributed along the peripheral cytoplasm and filopodia of both the trophic and cystic forms rather than in the inner side of the cytoplasm. Particularly, in the cystic forms, the amount of tubulin was increased and located mainly in the inner electron-lucent layer of the cell wall where the actin was concentrated as well. The results of this study showed that the cell wall of P carinii cystic forms is a structure whose inner side is rich in actin and tubulin. The location of the actin and tubulin in P. carinii suggests that the main role of these proteins is an involvement in the protection of cystic forms from the outside environment by maintaining rigidity of the cystic forms.

• Applied Microscopy
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• v.48 no.2
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• pp.33-42
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• 2018

Myosin X is one of myosin superfamily members having unique cellular functions on cytoskeletal reorganization. One of the most important cellular functions of myosin X is to facilitate the formation of membrane protrusions. Since membrane protrusions are important factors for diverse cellular motile processes including cell migration, cell invasion, path-finding of the cells, intercellular communications and so on, it has been thought that myosin X plays an important role in various processes that involve cytoskeletal reorganization including cancer progression and development of neuronal diseases. Recent studies have revealed that the unique cellular function of myosin X is closely correlated with its unique structural characteristics and motor properties. Moreover, it is found that the molecular and cellular activities of myosin X are controlled by its specific binding partner. Since recent studies have revealed the presence of various specific binding partners of myosin X, it is anticipated that the structural, biochemical and cell biological understanding of the binding partner dependent regulation of myosin X function can uncover the role of myosin X in diverse cell biological processes and diseases.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.9
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• pp.1288-1302
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• 2011

The aim of this study was to analyze the proteome expression of bovine satellite cells from longissimus dorsi (LD), deep pectoral (DP) and semitendinosus (ST) muscle depots during in vitro myogenic differentiation. Proteomic profiling by twodimensional gel electrophoresis and mass spectrometry of differentiating satellite cells revealed a total of 38 proteins that were differentially regulated among the three depots. Among differentially regulated proteins, metabolic proteins like lactate dehydrogenase (LDH), malate dehydrogenase (MDH) were found to be up regulated in ST, while alpha-enolase (NNE) in LD and DP depot satellite cells were down regulated. Also, our analysis found that there was a prominent up regulation of cytoskeletal proteins like actin, actincapping protein and transgelin along with chaperone proteins like heat shock protein beta 1 (HSPB 1) and T-complex protein 1 (TCP-1). Among other up regulated proteins, LIM domain containing protein, annexin 2 and Rho GDP-dissociation inhibitor 1 (Rho GDI) are observed, which were already proven to be involved in the myogeneis. More interestingly, satellite cells from ST depot were found to have a higher myotube formation rate than the cells from the other two depots. Taken together, our results demonstrated that, proteins involved in glucose metabolism, cytoskeletal modeling and protein folding plays a key role in the myogenic differentiation of bovine satellite cells.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.8
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• pp.1197-1204
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• 2012

The objective of this study was to investigate the effect of rapid chilling (RC) on beef quality and the degradation of cytoskeletal proteins. Twenty Chinese Yellow crossbred bulls were selected and randomly divided into two groups. RC and conventional chilling (CC) were applied to left and right sides of the carcasses respectively after slaughtering. To determine whether electrical stimulation (ES) treatment can alleviate the potential hazard of RC on meat quality, ES was applied to one group. The effects of RC and ES were determined by meat color, shear force and cytoskeletal protein degradation postmortem (PM). The results showed that RC decreased beef tenderness at 1 d and 3 d postmortem, but had no detrimental effect on meat color. Western blotting showed that RC decreased the degradation rate of desmin and troponin-T, but the effects weakened gradually as postmortem aging extended. Degradation rates of both desmin and troponin-T were accelerated by ES. The combination of RC and ES could improve beef color, accelerate degradation rate of cytoskeletal protein and improve beef tenderness.

• BMB Reports
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• v.29 no.5
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• pp.405-410
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• 1996

Previous studies have shown that transforming growth factor beta ($TGF-{\beta}$) is a potent regulator of cell growth and differentiation. To study the effects of $TGF-{\beta}$ on cell morphology and cytoskeleton reorganization, we conducted a survey using Mv1Lu mink lung epithelial cells with antibodies to cytoskeletal proteins and an extracellular matrix protein. While the untreated cells showed a cuboidal shape of typical epithelia, the Mv1Lu cells displayed a drastic shape change in the presence of $TGF-{\beta}$. This alteration was most prominent when near-confluent cells were treated with $TGF-{\beta}$. Since the morphology alteration is known to be accompanied by the reorganization of cytoskeletal proteins in other cell types, we investigated the intracellular distribution of the three major cytoskeletal structures: microfilaments, microtubules, and intermediate filaments. In the microfilament system, $TGF-{\beta}$ induced new stress fiber formation, which was caused primarily by the polymerization of cytoplasmic G-actin. However, $TGF-{\beta}$ appeared not to induce any significant changes in microtubular structures and vimentin filaments as determined by indirect fluorescence microscopy. Finally we confirmed the rapid accumulation of fibronectin by immunoblot analysis and chased the protein locations by immunofluorescence microscopy.

• Biomolecules & Therapeutics
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• v.4 no.4
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• pp.398-401
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• 1996

The glucose transporters found in the plasma membrane of all animal cells are known to have 12 putative transmembrane domains. Among 7 cytoplasmic loops, the fourth loop is the largest one. Since previous studies showed that cofilin, an actin-modulating protein, was found to interact with the largest cytoplasmic loop of (Na, K)ATPase, we tested if cofilin interacts with the largest cytoplasmic loop of Glut4. We demonstrated by the two-hybrid system that the largest cytoplasmic loop of Glut4 did not show any interaction with cofilin, suggesting that cofilin is not required for the membrane targeting process of other membrane proteins but only for a P-type ATPase.