Src kinase plays an important role in a multitude of fundamental cellular processes and is often found deregulated in tumors. Active Src adopts an open conformation, whereas inactive Src is characterized by a very compact structure stabilized by inhibitory intramolecular interactions. Taking advantage of this spatial regulation, we constructed a fluorescence resonance energy transfer (FRET)-based Src biosensor and analyzed conformational changes of Src following Src activation and the spatiotemporal dynamics of Src activity in cells. We found that activatory mutations either in regulatory or kinase domains induce opening of the Src structure. Surprisingly, we discovered that Src inhibitors differ in their effect on the Src structure, some counterintuitively inducing an open conformation. Finally, we analyzed the dynamics of Src activity in focal adhesions by FRET imaging and found that Src is rapidly activated during focal adhesion assembly, and its activity remains steady and high throughout the life cycle of focal adhesion and decreases during focal adhesion disassembly.

• MeSH
• biosenzitivní techniky metody   MeSH
• fokální adheze metabolismus   MeSH
• FRAP MeSH
• HEK293 buňky MeSH
• lidé MeSH
• mutageneze MeSH
• rezonanční přenos fluorescenční energie MeSH
• skupina kinas odvozených od src-genu antagonisté a inhibitory   genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The mechanoregulated proteins YAP/TAZ are involved in the adipogenic/osteogenic switch of mesenchymal stem cells (MSCs). MSC fate decision can be unbalanced by controlling substrate mechanics, in turn altering the transmission of tension through cell cytoskeleton. MSCs have been proposed for orthopedic and reconstructive surgery applications. Thus, a tight control of their adipogenic potential is required in order to avoid their drifting towards fat tissue. Substrate mechanics has been shown to drive MSC commitment and to regulate YAP/TAZ protein shuttling and turnover. The mechanism by which YAP/TAZ co-transcriptional activity is mechanically regulated during MSC fate acquisition is still debated. Here, we design few bioengineering tools suited to disentangle the contribution of mechanical from biological stimuli to MSC adipogenesis. We demonstrate that the mechanical repression of YAP happens through its phosphorylation, is purely mediated by cell spreading downstream of substrate mechanics as dictated by dimensionality. YAP repression is sufficient to prompt MSC adipogenesis, regardless of a permissive biological environment, TEAD nuclear presence or focal adhesion stabilization. Finally, by harnessing the potential of YAP mechanical regulation, we propose a practical example of the exploitation of adipogenic transdifferentiation in tumors.

• MeSH
• adaptorové proteiny signální transdukční metabolismus   MeSH
• adipogeneze * MeSH
• aktiny metabolismus   MeSH
• buněčné jádro metabolismus   MeSH
• extracelulární matrix metabolismus   MeSH
• fokální adheze metabolismus   MeSH
• fosforylace MeSH
• genetická transkripce MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• pohyb buněk * MeSH
• přeprogramování buněk MeSH
• proliferace buněk MeSH
• transkripční faktory metabolismus   MeSH
• tuková tkáň cytologie   MeSH
• tukové buňky metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Interaction of leukemia blasts with the bone marrow extracellular matrix often results in protection of leukemia cells from chemotherapy and in persistence of the residual disease which is on the basis of subsequent relapses. The adhesion signaling pathways have been extensively studied in adherent cells as well as in mature haematopoietic cells, but the adhesion structures and signaling in haematopoietic stem and progenitor cells, either normal or malignant, are much less explored. We analyzed the interaction of leukemia cells with fibronectin (FN) using interference reflection microscopy, immunofluorescence, measurement of adherent cell fraction, real-time microimpedance measurement and live cell imaging. We found that leukemia cells form very dynamic adhesion structures similar to early stages of focal adhesions. In contrast to adherent cells, where Src family kinases (SFK) belong to important regulators of focal adhesion dynamics, we observed only minor effects of SFK inhibitor dasatinib on leukemia cell binding to FN. The relatively weak involvement of SFK in adhesion structure regulation might be associated with the lack of cytoskeletal mechanical tension in leukemia cells. On the other hand, active Lyn kinase was found to specifically localize to leukemia cell adhesion structures and a less firm cell attachment to FN was often associated with higher Lyn activity (this unexpectedly occurred also after cell treatment with the inhibitor SKI-1). Lyn thus may be important for signaling from integrin-associated complexes to other processes in leukemia cells.

• MeSH
• buněčná adheze účinky léků   fyziologie   MeSH
• dasatinib farmakologie   MeSH
• fibronektiny metabolismus   MeSH
• fokální adheze účinky léků   metabolismus   MeSH
• fokální adhezní tyrosinkinasy metabolismus   MeSH
• fosforylace účinky léků   MeSH
• leukemie farmakoterapie   MeSH
• lidé MeSH
• skupina kinas odvozených od src-genu účinky léků   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The tyrosine kinase Src acts as a key regulator of cell motility by phosphorylating multiple protein substrates that control cytoskeletal and adhesion dynamics. In an earlier phosphotyrosine proteomics study, we identified a novel Rho-GTPase activating protein, now known as ARHGAP42, as a likely biologically relevant Src substrate. ARHGAP42 is a member of a family of RhoGAPs distinguished by tandem BAR-PH domains lying N-terminal to the GAP domain. Like other family members, ARHGAP42 acts preferentially as a GAP for RhoA. We show that Src principally phosphorylates ARHGAP42 on tyrosine 376 (Tyr-376) in the short linker between the BAR-PH and GAP domains. The expression of ARHGAP42 variants in mammalian cells was used to elucidate its regulation. We found that the BAR domain is inhibitory toward the GAP activity of ARHGAP42, such that BAR domain deletion resulted in decreased active GTP-bound RhoA and increased cell motility. With the BAR domain intact, ARHGAP42 GAP activity could be activated by phosphorylation of Tyr-376 to promote motile cell behavior. Thus, phosphorylation of ARHGAP42 Tyr-376 is revealed as a novel regulatory event by which Src can affect actin dynamics through RhoA inhibition.

• MeSH
• fokální adheze metabolismus   MeSH
• fosforylace MeSH
• lidé MeSH
• myši MeSH
• pohyb buněk fyziologie   MeSH
• proteiny aktivující GTPasu genetika   metabolismus   MeSH
• rho proteiny vázající GTP antagonisté a inhibitory   metabolismus   MeSH
• rhoA protein vázající GTP antagonisté a inhibitory   metabolismus   MeSH
• skupina kinas odvozených od src-genu metabolismus   MeSH
• tyrosin metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Hippo effectors YAP/TAZ act as on-off mechanosensing switches by sensing modifications in extracellular matrix (ECM) composition and mechanics. The regulation of their activity has been described by a hierarchical model in which elements of Hippo pathway are under the control of focal adhesions (FAs). Here we unveil the molecular mechanism by which cell spreading and RhoA GTPase activity control FA formation through YAP to stabilize the anchorage of the actin cytoskeleton to the cell membrane. This mechanism requires YAP co-transcriptional function and involves the activation of genes encoding for integrins and FA docking proteins. Tuning YAP transcriptional activity leads to the modification of cell mechanics, force development and adhesion strength, and determines cell shape, migration and differentiation. These results provide new insights into the mechanism of YAP mechanosensing activity and qualify this Hippo effector as the key determinant of cell mechanics in response to ECM cues.

• MeSH
• buněčná diferenciace genetika   fyziologie   MeSH
• buněčná membrána metabolismus   MeSH
• buněčné linie MeSH
• buněčný převod mechanických signálů genetika   fyziologie   MeSH
• extracelulární matrix metabolismus   MeSH
• fokální adheze genetika   metabolismus   fyziologie   MeSH
• HEK293 buňky MeSH
• jaderné proteiny genetika   metabolismus   MeSH
• lidé MeSH
• mikrofilamenta metabolismus   MeSH
• nádorové buněčné linie MeSH
• pohyb buněk genetika   fyziologie   MeSH
• rhoA protein vázající GTP genetika   metabolismus   MeSH
• stanovení celkové genové exprese MeSH
• transkripční faktory genetika   metabolismus   MeSH
• tvar buňky MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

CAS is a docking protein, which was shown to act as a mechanosensor in focal adhesions. The unique assembly of structural domains in CAS is important for its function as a mechanosensor. The tension within focal adhesions is transmitted to a stretchable substrate domain of CAS by focal adhesion-targeting of SH3 and CCH domain of CAS, which anchor the CAS protein in focal adhesions. Mechanistic models of the stretching biosensor propose equal roles for both anchoring domains. Using deletion mutants and domain replacements, we have analyzed the relative importance of the focal adhesion anchoring domains on CAS localization and dynamics in focal adhesions as well as on CAS-mediated mechanotransduction. We confirmed the predicted prerequisite of the focal adhesion targeting for CAS-dependent mechanosensing and unraveled the critical importance of CAS SH3 domain in mechanosensing. We further show that CAS localizes to the force transduction layer of focal adhesions and that mechanical stress stabilizes CAS in focal adhesions.

• MeSH
• buněčná adheze MeSH
• buněčný převod mechanických signálů * MeSH
• fibroblasty cytologie   metabolismus   MeSH
• fokální adheze metabolismus   MeSH
• mechanický stres MeSH
• mutantní proteiny chemie   MeSH
• myši MeSH
• proteinové domény MeSH
• rekombinantní fúzní proteiny metabolismus   MeSH
• signální transdukce MeSH
• stabilita proteinů MeSH
• substrátový protein asociovaný s Crk chemie   metabolismus   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• zelené fluorescenční proteiny metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Profilin controls actin nucleation and assembly processes in eukaryotic cells. Actin nucleation and elongation promoting factors (NEPFs) such as Ena/VASP, formins, and WASP-family proteins recruit profilin:actin for filament formation. Some of these are found to be microtubule associated, making actin polymerization from microtubule-associated platforms possible. Microtubules are implicated in focal adhesion turnover, cell polarity establishment, and migration, illustrating the coupling between actin and microtubule systems. Here we demonstrate that profilin is functionally linked to microtubules with formins and point to formins as major mediators of this association. To reach this conclusion, we combined different fluorescence microscopy techniques, including superresolution microscopy, with siRNA modulation of profilin expression and drug treatments to interfere with actin dynamics. Our studies show that profilin dynamically associates with microtubules and this fraction of profilin contributes to balance actin assembly during homeostatic cell growth and affects micro-tubule dynamics. Hence profilin functions as a regulator of microtubule (+)-end turnover in addition to being an actin control element.

• MeSH
• aktiny metabolismus   MeSH
• buněčná adheze MeSH
• buněčné kultury MeSH
• cytoskelet metabolismus   MeSH
• fetální proteiny metabolismus   MeSH
• fluorescenční mikroskopie MeSH
• fokální adheze metabolismus   MeSH
• HEK293 buňky MeSH
• jaderné proteiny metabolismus   MeSH
• lidé MeSH
• malá interferující RNA MeSH
• melanom experimentální MeSH
• mikrofilamenta metabolismus   MeSH
• mikrofilamentové proteiny metabolismus   MeSH
• mikrotubuly metabolismus   MeSH
• pohyb buněk fyziologie   MeSH
• profiliny metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The incidence of renal cell carcinoma (RCC) is increasing worldwide, and its prevalence is particularly high in some parts of Central Europe. Here we undertake whole-genome and transcriptome sequencing of clear cell RCC (ccRCC), the most common form of the disease, in patients from four different European countries with contrasting disease incidence to explore the underlying genomic architecture of RCC. Our findings support previous reports on frequent aberrations in the epigenetic machinery and PI3K/mTOR signalling, and uncover novel pathways and genes affected by recurrent mutations and abnormal transcriptome patterns including focal adhesion, components of extracellular matrix (ECM) and genes encoding FAT cadherins. Furthermore, a large majority of patients from Romania have an unexpected high frequency of A:T>T:A transversions, consistent with exposure to aristolochic acid (AA). These results show that the processes underlying ccRCC tumorigenesis may vary in different populations and suggest that AA may be an important ccRCC carcinogen in Romania, a finding with major public health implications.

• MeSH
• dospělí MeSH
• fokální adheze metabolismus   MeSH
• fosfatidylinositol-3-kinasy genetika   MeSH
• fúzní onkogenní proteiny genetika   MeSH
• genetická variace * MeSH
• genom lidský genetika   MeSH
• genomika * MeSH
• karcinom z renálních buněk genetika   MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• mutace MeSH
• mutační rychlost MeSH
• regulace genové exprese u nádorů MeSH
• sekvenční analýza DNA MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• sestřih RNA genetika   MeSH
• signální transdukce genetika   MeSH
• stanovení celkové genové exprese MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Evropa MeSH

Physicochemical interactions between the cell and its environment are crucial for morphogenesis, tissue homeostasis, remodeling and pathogenesis. Cells form specialized structures like focal adhesions and podosomes that are responsible for bi-directional information exchange between the cell and its surroundings. Besides their role in the transmission of regulatory signals, these structures are also involved in mechanosensing and mechanotransduction. In the past few years, many research groups have been trying to elucidate the mechanisms and consequences of the mechanosensitivity of cells. In this review we discuss the role of the integrin pathway in cellular mechanosensing, focusing on primary mechanosensors, molecules that respond to mechanical stress by changing their conformation. We propose mechanisms by which p130Cas is involved in this process, and emphasize the importance of mechanosensing in cell physiology and the development of diseases.

• MeSH
• buněčné výběžky metabolismus   MeSH
• buněčný převod mechanických signálů fyziologie   MeSH
• fokální adheze metabolismus   MeSH
• integriny metabolismus   MeSH
• lidé MeSH
• mechanický stres MeSH
• mikrofilamenta metabolismus   MeSH
• substrátový protein asociovaný s Crk metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Focal adhesions are cellular structures through which both mechanical forces and regulatory signals are transmitted. Two focal adhesion-associated proteins, Crk-associated substrate (CAS) and vinculin, were both independently shown to be crucial for the ability of cells to transmit mechanical forces and to regulate cytoskeletal tension. Here, we identify a novel, direct binding interaction between CAS and vinculin. This interaction is mediated by the CAS SRC homology 3 domain and a proline-rich sequence in the hinge region of vinculin. We show that CAS localization in focal adhesions is partially dependent on vinculin, and that CAS-vinculin coupling is required for stretch-induced activation of CAS at the Y410 phosphorylation site. Moreover, CAS-vinculin binding significantly affects the dynamics of CAS and vinculin within focal adhesions as well as the size of focal adhesions. Finally, disruption of CAS binding to vinculin reduces cell stiffness and traction force generation. Taken together, these findings strongly implicate a crucial role of CAS-vinculin interaction in mechanosensing and focal adhesion dynamics.

• MeSH
• aminokyselinové motivy MeSH
• biomechanika MeSH
• buněčná adheze MeSH
• buněčné linie MeSH
• fibroblasty cytologie   metabolismus   MeSH
• fokální adheze metabolismus   ultrastruktura   MeSH
• fokální adhezní tyrosinkinasy metabolismus   MeSH
• fosforylace MeSH
• mapy interakcí proteinů MeSH
• myši MeSH
• peptidy chemie   metabolismus   MeSH
• src homologní domény MeSH
• substrátový protein asociovaný s Crk analýza   metabolismus   MeSH
• vazba proteinů MeSH
• vinkulin analýza   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH