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Unraveling the determinants of protrusion formation.

Varghese M, Gorsevski P, Cayer ML, Boudreau NS, Heckman CA - Int J Cell Biol (2012)

Bottom Line: The results show that FC maturation/cytoskeletal integration affects factor 5, because FC elongation/integration was correlated with its values.Where integration did occur, the cables showed distinctive size and orientation, as indicated by correlation of 7 values with FC shape.We conclude that cells establish functional domains by rearranging the cytoskeleton.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403-0212, USA.

ABSTRACT
A COMPUTERIZED MORPHOMETRIC CLASSIFICATION TECHNIQUE BASED ON LATENT FACTORS REVEALS MAJOR PROTRUSION CLASSES: factors 4, 5, and 7. Previous work showed that factor 4 represented filopodia, 5 the distribution of lamellar cytoplasm, and 7 a blunt protrusion. We explore the relationship of focal contact (FC) characteristics and their integrated actin cables to factors values. The results show that FC maturation/cytoskeletal integration affects factor 5, because FC elongation/integration was correlated with its values. On the contrary, 7 values decreased with maturation, so cable or FC size or their integration must be restricted to form these protrusions. Where integration did occur, the cables showed distinctive size and orientation, as indicated by correlation of 7 values with FC shape. Results obtained with myosin inhibitors support the interpretation that a central, isometric, contractile network puts constraints on both factor 5 and 7 protrusions. We conclude that cells establish functional domains by rearranging the cytoskeleton.

No MeSH data available.


Related in: MedlinePlus

MetaMorph image showing representative FCs. Those with a large width compared to their length are designated (arrowheads). They were overlapping in the image due to converging angles of orientation (a) or lying at too close a distance to be resolved separately (b).
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fig7: MetaMorph image showing representative FCs. Those with a large width compared to their length are designated (arrowheads). They were overlapping in the image due to converging angles of orientation (a) or lying at too close a distance to be resolved separately (b).

Mentions: Remarkably, for the category of FCs with actin integration, two variables, namely, the inner radius and fiber breadth, were positively correlated with factor 7 values. Since both showed an inversion of the normal sign of the PCC (Pearson coefficient), the usual relationship between FC dimensions and factor 7 value was reversed for these FCs. Moreover, these PCCs were highly significant (Table 3). That the PCC for fiber breadth showed either a negative or positive sign, depending on the category of actin integration with the FC, suggested that there was a population of more stable FCs supporting the formation of factor 7 features. This finding explained the low absolute value of the correlation coefficients with factor 7, as both negative and positive relationships were rolled into the overall correlation. As FC length and outer radius were uncorrelated with factor 7, the FCs in this new category were small in all dimensions except width. This was confirmed by directly plotting the factor 7 values against the relative dimensions of FCs in the two classes. The raw values of centroid coordinates in the X and Y dimensions were plotted, because no external data were entered to normalize these values in the MetaMorph software (Figures 5 and 6). Because FCs with a fat contour were rare in the processed black-and-white images, we further explored the data by selecting FCs in the with-actin category that showed low ellipticity measurements. The results suggest that the FCs with dimensions positively correlated with factor 7 values are FCs with different orientations as shown in Figure 7.


Unraveling the determinants of protrusion formation.

Varghese M, Gorsevski P, Cayer ML, Boudreau NS, Heckman CA - Int J Cell Biol (2012)

MetaMorph image showing representative FCs. Those with a large width compared to their length are designated (arrowheads). They were overlapping in the image due to converging angles of orientation (a) or lying at too close a distance to be resolved separately (b).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3303863&req=5

fig7: MetaMorph image showing representative FCs. Those with a large width compared to their length are designated (arrowheads). They were overlapping in the image due to converging angles of orientation (a) or lying at too close a distance to be resolved separately (b).
Mentions: Remarkably, for the category of FCs with actin integration, two variables, namely, the inner radius and fiber breadth, were positively correlated with factor 7 values. Since both showed an inversion of the normal sign of the PCC (Pearson coefficient), the usual relationship between FC dimensions and factor 7 value was reversed for these FCs. Moreover, these PCCs were highly significant (Table 3). That the PCC for fiber breadth showed either a negative or positive sign, depending on the category of actin integration with the FC, suggested that there was a population of more stable FCs supporting the formation of factor 7 features. This finding explained the low absolute value of the correlation coefficients with factor 7, as both negative and positive relationships were rolled into the overall correlation. As FC length and outer radius were uncorrelated with factor 7, the FCs in this new category were small in all dimensions except width. This was confirmed by directly plotting the factor 7 values against the relative dimensions of FCs in the two classes. The raw values of centroid coordinates in the X and Y dimensions were plotted, because no external data were entered to normalize these values in the MetaMorph software (Figures 5 and 6). Because FCs with a fat contour were rare in the processed black-and-white images, we further explored the data by selecting FCs in the with-actin category that showed low ellipticity measurements. The results suggest that the FCs with dimensions positively correlated with factor 7 values are FCs with different orientations as shown in Figure 7.

Bottom Line: The results show that FC maturation/cytoskeletal integration affects factor 5, because FC elongation/integration was correlated with its values.Where integration did occur, the cables showed distinctive size and orientation, as indicated by correlation of 7 values with FC shape.We conclude that cells establish functional domains by rearranging the cytoskeleton.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403-0212, USA.

ABSTRACT
A COMPUTERIZED MORPHOMETRIC CLASSIFICATION TECHNIQUE BASED ON LATENT FACTORS REVEALS MAJOR PROTRUSION CLASSES: factors 4, 5, and 7. Previous work showed that factor 4 represented filopodia, 5 the distribution of lamellar cytoplasm, and 7 a blunt protrusion. We explore the relationship of focal contact (FC) characteristics and their integrated actin cables to factors values. The results show that FC maturation/cytoskeletal integration affects factor 5, because FC elongation/integration was correlated with its values. On the contrary, 7 values decreased with maturation, so cable or FC size or their integration must be restricted to form these protrusions. Where integration did occur, the cables showed distinctive size and orientation, as indicated by correlation of 7 values with FC shape. Results obtained with myosin inhibitors support the interpretation that a central, isometric, contractile network puts constraints on both factor 5 and 7 protrusions. We conclude that cells establish functional domains by rearranging the cytoskeleton.

No MeSH data available.


Related in: MedlinePlus