Ponticulin plays a role in the positional stabilization of pseudopods.

Shutt, Damon C.; Wessels, Deborah; Wagenknecht, K.; Chandrasekhar, Anand; Hitt, Anne L.; Luna, Elizabeth J.; Soll, David R.

doi:10.1083/jcb.131.6.1495

Cited by 39 publications

(40 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Over 90% of regA Ϫ cells chemotaxed up the spatial gradient, roughly the same proportion as Ax4 cells. The chemotactic index (ϮSD) of regA Ϫ cells was ϩ0.48 Ϯ 0.28, which is comparable to the chemotactic indices of several other normal strains of Dictyostelium (Shutt et al, 1995;Cox et al, 1996) but is lower than that of the parent Ax4 strain. The difference between the chemotactic index of Ax4 and regA Ϫ cells was because of a depression in high-end chemotactic indices (i.e., those Նϩ0.80).…”

Section: Rega Is Not Necessary For Assessing the Direction Of A Spatisupporting

confidence: 66%

“…The velocity of individual cells changes during the early developmental stages of Dictyostelium (Varnum et al, 1985;Shutt et al, 1995). The instantaneous velocity of cells is low at the beginning of the developmental program, increases to a peak value at the onset of aggregation, and then decreases through the later stages of development.…”

Section: Basic Motility Of Rega ؊ Cellsmentioning

confidence: 99%

See 1 more Smart Citation

The Internal Phosphodiesterase RegA Is Essential for the Suppression of Lateral Pseudopods duringDictyosteliumChemotaxis

Wessels

Zhang

Reynolds

et al. 2000

MBoC

View full text Add to dashboard Cite

Dictyostelium strains in which the gene encoding the cytoplasmic cAMP phosphodiesterase RegA is inactivated form small aggregates. This defect was corrected by introducing copies of the wild-type regA gene, indicating that the defect was solely the consequence of the loss of the phosphodiesterase. Using a computer-assisted motion analysis system, regA Ϫ mutant cells were found to show little sense of direction during aggregation. When labeled wild-type cells were followed in a field of aggregating regA Ϫ cells, they also failed to move in an orderly direction, indicating that signaling was impaired in mutant cell cultures. However, when labeled regA Ϫ cells were followed in a field of aggregating wild-type cells, they again failed to move in an orderly manner, primarily in the deduced fronts of waves, indicating that the chemotactic response was also impaired. Since wild-type cells must assess both the increasing spatial gradient and the increasing temporal gradient of cAMP in the front of a natural wave, the behavior of regA Ϫ cells was motion analyzed first in simulated temporal waves in the absence of spatial gradients and then was analyzed in spatial gradients in the absence of temporal waves. Our results demonstrate that RegA is involved neither in assessing the direction of a spatial gradient of cAMP nor in distinguishing between increasing and decreasing temporal gradients of cAMP. However, RegA is essential for specifically suppressing lateral pseudopod formation during the response to an increasing temporal gradient of cAMP, a necessary component of natural chemotaxis. We discuss the possibility that RegA functions in a network that regulates myosin phosphorylation by controlling internal cAMP levels, and, in support of that hypothesis, we demonstrate that myosin II does not localize in a normal manner to the cortex of regA Ϫ cells in an increasing temporal gradient of cAMP.

show abstract

Section: Rega Is Not Necessary For Assessing the Direction Of A Spatisupporting

confidence: 66%

Section: Basic Motility Of Rega ؊ Cellsmentioning

confidence: 99%

The Internal Phosphodiesterase RegA Is Essential for the Suppression of Lateral Pseudopods duringDictyosteliumChemotaxis

Wessels

Zhang

Reynolds

et al. 2000

MBoC

View full text Add to dashboard Cite

show abstract

“…In a spatial or increasing temporal gradient of cAMP, the average frequency of lateral pseudopod formation of wild-type cells is reduced to once every 4-5 minutes (Kumar et al, 2004;Shutt et al, 1995;Stepanovic et al, 2005;Varnum-Finney et al, 1987a;Wessels et al, 2000a;Wessels et al, 2000b;Zhang et al, 2003). In marked contrast, pten -cells challenged with spatial or temporal gradients of cAMP continued to form lateral pseudopods at abnormally high frequency, and continued to extend them in parallel and from the rear of the cell.…”

Section: Pten's Role Is Constitutivementioning

confidence: 99%

“…They included the null mutant of the myosin II heavy chain (MHC), mhcA - (Wessels et al, 1989;Wessels and Soll, 1990;Peters et al, 1988;Sheldon and Knecht, 1996;Heid et al, 2004), the MHC dephosphorylation mutant, 3XASP (Heid et al, 2004), the null mutant of clathrin, chc - (Wessels et al, 2000a), the null mutant for sphingosine-1-phosphate (S-1-P) lyase (Kumar et al, 2004), and null mutants of three class I myosins, myoB -, myoA -and myoF - (Falk et al, 2003;Titus et al, 1993;Wessels et al, 1996). The remaining mutants that were subjected to computer-assisted methods exhibited a variety of behavioral defects quite distinct from those of pten -and this subset (Cox et al, 1992;Cox et al, 1996;Alexander et al, 1992;Shutt et al, 1995;Wessels et al, 2000a;Wessels et al, 2000b;Zhang et al, 2002;Bosgraaf et al, 2002;Bosgraaf et al, 2005;Stepanovic et al, 2005).…”

Section: Pten and The Cortical Localization Of Myosin II And F-actinmentioning

confidence: 99%

PTEN plays a role in the suppression of lateral pseudopod formation duringDictyosteliummotility and chemotaxis

Wessels

Lusche

Kuhl

et al. 2007

Journal of Cell Science

112

View full text Add to dashboard Cite

It has been suggested that the phosphatydylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P3] phosphatase and tensin homolog PTEN plays a fundamental role in Dictyostelium discoideum chemotaxis. To identify that role, the behavior of a pten– mutant was quantitatively analyzed using two-dimensional and three-dimensional computer-assisted methods. pten– cells were capable of polarizing and translocating in the absence of attractant, and sensing and responding to spatial gradients, temporal gradients and natural waves of attractant. However, all of these responses were compromised (i.e. less efficient) because of the fundamental incapacity of pten– cells to suppress lateral pseudopod formation and turning. This defect was equally manifested in the absence, as well as presence, of attractant. PTEN, which is constitutively localized in the cortex of polarized cells, was found essential for the attractant-stimulated increase in cortical myosin II and F-actin that is responsible for the increased suppression of pseudopods during chemotaxis. PTEN, therefore, plays a fundamental role in the suppression of lateral pseudopod formation, a process essential for the efficiency of locomotion and chemotaxis, but not in directional sensing.

show abstract

“…We previously presented data suggesting that the position of a retracting pseudopod in a wild-type cell is fixed in relation to the substratum (59). This is evident in the time sequence of cell reconstructions in Fig.…”

Section: Vol 8 2009 How a Cell Crawls 1385mentioning

confidence: 66%

How a Cell Crawls and the Role of Cortical Myosin II

et al. 2009

View full text Add to dashboard Cite

The movements of Dictyostelium discoideum amoebae translocating on a glass surface in the absence of chemoattractant have been reconstructed at 5-second intervals and motion analyzed by employing 3D-DIAS software. A morphometric analysis of pseudopods, the main cell body, and the uropod provides a comprehensive description of the basic motile behavior of a cell in four dimensions (4D), resulting in a list of 18 characteristics. A similar analysis of the myosin II phosphorylation mutant 3XASP reveals a role for the cortical localization of myosin II in the suppression of lateral pseudopods, formation of the uropod, cytoplasmic distribution of cytoplasm in the main cell body, and efficient motility. The results of the morphometric analysis suggest that pseudopods, the main cell body, and the uropod represent three motility compartments that are coordinated for efficient translocation. It provides a contextual framework for interpreting the effects of mutations, inhibitors, and chemoattractants on the basic motile behavior of D. discoideum. The generality of the characteristics of the basic motile behavior of D. discoideum must now be tested by similar 4D analyses of the motility of amoeboid cells of higher eukaryotic cells, in particular human polymorphonuclear leukocytes.Amoeboid behavior is a characteristic of cells spanning the entire animal kingdom (5,6,15,56). It is basic to the life history of soil amoebae, embryogenesis, white blood cell function, tissue regeneration, neural development, and cancer metastasis (52). Therefore, the molecular biology of this process has been the focus of intensive investigation (2,15,40,50,53,57). In marked contrast, the basic motile behavior of amoeboid cells, which provides the contextual framework for interpreting the results of genetic and biochemical studies, has received far less attention. We still lack an accurate and quantitative fourdimensional (4D) description of how an amoeboid cell translocates along a substratum in the absence of a chemotactic signal. The lack of such a description has led to perceptions of single cell migration that are 2D, sometimes oversimplified, and sometimes actually inaccurate. These perceptions, unfortunately, have served as the basis for modeling cell locomotion, interpreting the behavioral defects of cytoskeletal and regulatory mutants, and assessing the effects of inhibitors and stimuli, most notably chemoattractants.To obtain a 4D description of cell behavior, we have employed 3D-DIAS software (25,61,62,64,78) to reconstruct and motion analyze the basic motile behavior of Dictyostelium discoideum amoebae translocating along a substratum in the absence of chemoattractant (63,71,76,77,79,80). By quantitating in space and time the extension and retraction of pseudopods, changes in shape, anterior progress of the main cell body and uropod, and contact of the ventral surface of the cell with the substratum, we have developed a complex morphometric description of cell migration that reveals a number of characteristics. In addition, by simil...

show abstract

Ponticulin plays a role in the positional stabilization of pseudopods.

Cited by 39 publications

References 52 publications

The Internal Phosphodiesterase RegA Is Essential for the Suppression of Lateral Pseudopods duringDictyosteliumChemotaxis

The Internal Phosphodiesterase RegA Is Essential for the Suppression of Lateral Pseudopods duringDictyosteliumChemotaxis

PTEN plays a role in the suppression of lateral pseudopod formation duringDictyosteliummotility and chemotaxis

How a Cell Crawls and the Role of Cortical Myosin II

Contact Info

Product

Resources

About