| 1. |
- Bolshakova, A.V., et al.
(författare)
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The comparative analysis of subcellular fractionation methods for revealing of a-actinin 1 and a-actinin 4 in A431 cells
- 2009
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Ingår i: Tsitologiya. - St Petersburg, Russian Federation : Sankt-Peterburgskaya Izdatel'skaya Firma Nauka. - 0041-3771. ; 51:2, s. 122-129
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Tidskriftsartikel (refereegranskat)abstract
- a-Actinin 1 and a-actinin 4 belong to a family of actin-binding proteins with shared structural function and regulation of several processes in a cell. Based on previous data on different distribution of these proteins in the nucleus and cytoplasm, we have explored in detail the distribution of a-actinin 1 and a-actinin 4 in subcellular fractions in A431 cells spread on fibronectin. Several methods of subcellular fractionation were used. Complex approach allowed resuming that revealing of a-actinin isoforms in fractions depended on the composition of lysis buffer and preliminary low-temperature freezing of the cells. We have drawn a conclusion that a-actinin 4 can be found in all cytoplasmic and nuclear subfractions, while a-actinin 1 is characterized by cytoplasmic and membrane localization with specificity of its distribution tightly to the nuclear membrane.
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| 2. |
- Khotin, M.G., et al.
(författare)
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Analysis of nuclear protein complexes comprising a-actinin-4 by 2D-electrophoresis and mass-spectrometry
- 2009
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Ingår i: Tsitologiya. - : SP MAIK Nauka/Interperiodica. - 0041-3771. ; 51:8, s. 684-690
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Tidskriftsartikel (refereegranskat)abstract
- Actin-binding protein a-actinin-4 is a member of spectrin super family. It is located in the cytoplasm and in the nucleus. However, nuclear functions of a-actinin-4 are still not clear. In this study, we analyzed composition of nuclear protein complexes associated with a-actinin-4 in A431 cells. Using 2D electrophoresis, we have determined that about 50 different proteins may be associated with nuclear a-actinin-4. Using mass-spectrometry, we analyzed major proteins of these complexes. ß-Actin, a- and ß-tubulins, ribonucleoprotein A2/B1, which regulates splicing and is associated with ß-actin, peroxiredoxin-1, which is involved in oxidative stress, and glycolytic enzyme D-3-phosphoglycerate dehydrogenase were identified by MALDI-TOF. Detection of these proteins in nuclear complexes with a-actinin-4 may suggest that a-actinin-4 is involved in transcription and splicing. Presence of a-actin in the investigated complexes was confirmed by tandem mass-spectrometry (MALDITOF-TOF). Immunoprecipitation of nuclear proteins with antibodies against a-tubulin confirmed association of a-actinin-4 with a-tubulin in the protein complex. Nuclear a-actinin-4 constitutes of 105 KDa fullsize isoform and two truncated isoforms of 65 and 75 kDa, whereas only the truncated isoform have been found in nuclear complexes with a-tubulin. These data suggest that a-actinin-4 is associated with a number of different nuclear protein complexes which may carry out different functions in the cell nucleus.
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| 3. |
- Turoverova, L.V., et al.
(författare)
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Analysis of extracellular matrix proteins produced by cultured cells
- 2009
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Ingår i: Tsitologiya. - St Petersburg, Russian Federation : Sankt-Peterburgskaya Izdatel'skaya Firma Nauka. - 0041-3771. ; 51:8, s. 691-696
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Tidskriftsartikel (refereegranskat)abstract
- Extracellular matrix (ECM) is a highly organized multimolecular structure essential for vital function of any organism. Although a lot of data on the extracellular matrix components has been accumulated, an isolation of the entire set of these proteins still remains to be a complex procedure since ECM contains fibrillar proteins and proteoglycans, which form multidomain net-like structures. In the presented study, we developed a method for isolation of ECM proteins from cell cultures. Human epidermoid carcinoma cells A431 and fibroblasts obtained from normal and scar human skin were used. We showed that EDTA solution removed cells from culture plates without destroying the cell membrane. Following treatment of remaining ECM proteins with acetic acid in order to dissociate collagen fibrils significantly improved fractioning of ECM proteins. Extraction of the remained proteins from culture plate surface was preformed using a buffer developed on the basis of Laemmli probe buffer. With this method, we isolated ECM proteins synthesized by culturing cells and suitable for a future analysis by SDS PAGE and two-dimentional electrophoresis as well as for identification of individual proteins by mass-spectrometry. This study may allow comparing protein contents of ECMs isolated from different sources, and elucidate influences of various proteins on the protein and the properties of extracellular matrix of investigated cells.
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