scholarly journals Distinct Pathways for the Early Recruitment of Myosin II and Actin to the Cytokinetic Furrow

2008 ◽  
Vol 19 (1) ◽  
pp. 318-326 ◽  
Author(s):  
Mian Zhou ◽  
Yu-Li Wang
Keyword(s):  
Actin Filaments ◽  
Mammalian Cells ◽  
De Novo ◽  
Myosin Ii ◽  
Correlation Spectroscopy ◽  
Image Correlation ◽  
Animal Cells ◽  
Image Correlation Spectroscopy ◽  
Early Recruitment ◽  
Actin Concentration

Equatorial organization of myosin II and actin has been recognized as a universal event in cytokinesis of animal cells. Current models for the formation of equatorial cortex favor either directional cortical transport toward the equator or localized de novo assembly. However, this process has never been analyzed directly in dividing mammalian cells at a high resolution. Here we applied total internal reflection fluorescence microscope (TIRF-M), coupled with spatial temporal image correlation spectroscopy (STICS) and a new analytical approach termed temporal differential microscopy (TDM), to image the dynamics of myosin II and actin during the assembly of equatorial cortex. Our results indicated distinct and at least partially independent mechanisms for the early equatorial recruitment of myosin and actin filaments. Cortical myosin showed no detectable directional flow during early cytokinesis. In addition to equatorial assembly, we showed that localized inhibition of disassembly contributed to the formation of the equatorial myosin band. In contrast to myosin, actin filaments underwent a striking flux toward the equator. Myosin motor activity was required for the actin flux, but not for actin concentration in the furrow, suggesting that there was a flux-independent, de novo mechanism for actin recruitment along the equator. Our results indicate that cytokinesis involves signals that regulate both assembly and disassembly activities and argue against mechanisms that are coupled to global cortical movements.

scholarly journals Adhesion-dependent and Contractile Ring-independent Equatorial Furrowing during Cytokinesis in Mammalian Cells

2005 ◽  
Vol 16 (8) ◽  
pp. 3865-3872 ◽  
Author(s):  
Masamitsu Kanada ◽  
Akira Nagasaki ◽  
Taro Q.P. Uyeda
Keyword(s):  
Mammalian Cells ◽  
Rat Kidney ◽  
Myosin Ii ◽  
Rho Kinase ◽  
Cellular Slime Mold ◽  
Animal Cells ◽  
Contractile Ring ◽  
Normal Rat ◽  
Cellular Slime ◽  
Coated Surfaces

Myosin II-dependent contraction of the contractile ring drives equatorial furrowing during cytokinesis in animal cells. Nonetheless, myosin II-null cells of the cellular slime mold Dictyostelium divide efficiently when adhering to substrates by making use of polar traction forces. Here, we show that in the presence of 30 μM blebbistatin, a potent myosin II inhibitor, normal rat kidney (NRK) cells adhering to fibronectin-coated surfaces formed equatorial furrows and divided in a manner strikingly similar to myosin II-null Dictyostelium cells. Such blebbistatin-resistant cytokinesis was absent in partially detached NRK cells and was disrupted in adherent cells if the advance of their polar lamellipodia was disturbed by neighboring cells. Y-27632 (40 μM), which inhibits Rho-kinase, was similar to 30 μM blebbistatin in that it inhibited cytokinesis of partially detached NRK cells but only prolonged furrow ingression in attached cells. In the presence of 100 μM blebbistatin, most NRK cells that initiated anaphase formed tight furrows, although scission never occurred. Adherent HT1080 fibrosarcoma cells also formed equatorial furrows efficiently in the presence of 100 μM blebbistatin. These results provide direct evidence for adhesion-dependent, contractile ring-independent equatorial furrowing in mammalian cells and demonstrate the importance of substrate adhesion for cytokinesis.

Exploring oligomeric state of the serotonin1A receptor utilizing photobleaching image correlation spectroscopy: implications for receptor function

2018 ◽  
Vol 207 ◽  
pp. 409-421 ◽  
Author(s):  
Hirak Chakraborty ◽  
Md. Jafurulla ◽  
Andrew H. A. Clayton ◽  
Amitabha Chattopadhyay
Keyword(s):  
Correlation Spectroscopy ◽  
Image Correlation ◽  
Membrane Cholesterol ◽  
Receptor Function ◽  
Oligomeric State ◽  
Serotonin1a Receptor ◽  
Image Correlation Spectroscopy

Photobleaching image correlation spectroscopy (pbICS) reveals that membrane cholesterol modulates the oligomeric state of the serotonin1A receptor.

scholarly journals Arbitrary-Region Image Correlation Spectroscopy

2016 ◽  
Vol 110 (3) ◽  
pp. 176a
Author(s):  
Jelle Hendrix ◽  
Tomas Dekens ◽  
Don C. Lamb
Keyword(s):  
Correlation Spectroscopy ◽  
Image Correlation ◽  
Arbitrary Region ◽  
Image Correlation Spectroscopy

scholarly journals Visualization of class A GPCR oligomerization by image-based fluorescence fluctuation spectroscopy

2017 ◽  
Author(s):  
Ali Isbilir ◽  
Jan Möller ◽  
Andreas Bock ◽  
Ulrike Zabel ◽  
Paolo Annibale ◽  
...  
Keyword(s):  
Single Molecule ◽  
Metabotropic Glutamate Receptors ◽  
Fluorescent Protein ◽  
Methodological Approach ◽  
Correlation Spectroscopy ◽  
Membrane Receptors ◽  
Image Correlation ◽  
Intact Cells ◽  
Class A ◽  
Image Correlation Spectroscopy

AbstractG protein-coupled receptors (GPCRs) represent the largest class of cell surface receptors conveying extracellular information into intracellular signals. Many GPCRs have been shown to be able to oligomerize and it is firmly established that Class C GPCRs (e.g. metabotropic glutamate receptors) function as obligate dimers. However, the oligomerization capability of the larger Class A GPCRs (e.g. comprising the β-adrenergic receptors (β-ARs)) is still, despite decades of research, highly debated.Here we assess the oligomerization behavior of three prototypical Class A GPCRs, the β1-ARs, β2-ARs, and muscarinic M2Rs in single, intact cells. We combine two image correlation spectroscopy methods based on molecular brightness, i.e. the analysis of fluorescence fluctuations over space and over time, and thereby provide an assay able to robustly and precisely quantify the degree of oligomerization of GPCRs. In addition, we provide a comparison between two labelling strategies, namely C-terminally-attached fluorescent proteins and N-terminally-attached SNAP-tags, in order to rule out effects arising from potential fluorescent protein-driven oligomerization. The degree of GPCR oligomerization is expressed with respect to a set of previously reported as well as newly established monomeric or dimeric control constructs. Our data reveal that all three prototypical GPRCs studied display, under unstimulated conditions, a prevalently monomeric fingerprint. Only the β2-AR shows a slight degree of oligomerization.From a methodological point of view, our study suggests three key aspects. First, the combination of two image correlation spectroscopy methods allows addressing cells transiently expressing high concentrations of membrane receptors, far from the single molecule regime, at a density where the kinetic equilibrium should favor dimers and higher-order oligomers. Second, our methodological approach, allows to selectively target cell membrane regions devoid of artificial oligomerization hot-spots (such as vesicles). Third, our data suggest that the β1-AR appears to be a superior monomeric control than the widely used membrane protein CD86.Taken together, we suggest that our combined image correlation spectroscopy method is a powerful approach to assess the oligomerization behavior of GPCRs in intact cells at high expression levels.

Raster image correlation spectroscopy as a novel tool to study interactions of macromolecules with nanofiber scaffolds

2011 ◽  
Vol 7 (12) ◽  
pp. 4195-4203 ◽  
Author(s):  
S.C.P. Norris ◽  
J. Humpolíčková ◽  
E. Amler ◽  
M. Huranová ◽  
M. Buzgo ◽  
...  
Keyword(s):  
Correlation Spectroscopy ◽  
Image Correlation ◽  
Raster Image ◽  
Nanofiber Scaffolds ◽  
Image Correlation Spectroscopy

scholarly journals Image Correlation Spectroscopy of Multiphoton Images Correlates with Collagen Mechanical Properties

2008 ◽  
Vol 94 (6) ◽  
pp. 2361-2373 ◽  
Author(s):  
Christopher B. Raub ◽  
Jay Unruh ◽  
Vinod Suresh ◽  
Tatiana Krasieva ◽  
Tore Lindmo ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Correlation Spectroscopy ◽  
Image Correlation ◽  
Image Correlation Spectroscopy

scholarly journals Fusion of Sendai virus and individual host cells and inhibition of fusion by lipophosphoglycan measured with image correlation spectroscopy

1998 ◽  
Vol 1404 (3) ◽  
pp. 338-352 ◽  
Author(s):  
Birgitta J. Rasmusson ◽  
Thomas D. Flanagan ◽  
Salvatore J. Turco ◽  
Richard M. Epand ◽  
Nils O. Petersen
Keyword(s):  
Sendai Virus ◽  
Correlation Spectroscopy ◽  
Image Correlation ◽  
Host Cells ◽  
Individual Host ◽  
Image Correlation Spectroscopy
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