Pablo A Iglesias

Summary

Affiliation: Johns Hopkins University
Country: USA

Publications

  1. pmc Quantifying robustness of biochemical network models
    Lan Ma
    Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD USA
    BMC Bioinformatics 3:38. 2002
  2. pmc Biased excitable networks: how cells direct motion in response to gradients
    Pablo A Iglesias
    Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, United States
    Curr Opin Cell Biol 24:245-53. 2012
  3. doi request reprint Chemoattractant signaling in dictyostelium: adaptation and amplification
    Pablo A Iglesias
    Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
    Sci Signal 5:pe8. 2012
  4. pmc A method for determining the robustness of bio-molecular oscillator models
    Reza Ghaemi
    Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
    BMC Syst Biol 3:95. 2009
  5. doi request reprint Spatial regulation of PI3K signaling during chemotaxis
    Pablo A Iglesias
    Department of Electrical and Computer Engineering, The Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
    Wiley Interdiscip Rev Syst Biol Med 1:247-53. 2009
  6. doi request reprint Navigating through models of chemotaxis
    Pablo A Iglesias
    Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
    Curr Opin Cell Biol 20:35-40. 2008
  7. doi request reprint A systems biology view of adaptation in sensory mechanisms
    Pablo A Iglesias
    Department of Electrical and Computer Engineering, The Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA
    Adv Exp Med Biol 736:499-516. 2012
  8. pmc tsunami, the Dictyostelium homolog of the Fused kinase, is required for polarization and chemotaxis
    Linnan Tang
    Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
    Genes Dev 22:2278-90. 2008
  9. pmc Automated characterization of cell shape changes during amoeboid motility by skeletonization
    Yuan Xiong
    Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
    BMC Syst Biol 4:33. 2010
  10. pmc Two complementary, local excitation, global inhibition mechanisms acting in parallel can explain the chemoattractant-induced regulation of PI(3,4,5)P3 response in dictyostelium cells
    Lan Ma
    Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
    Biophys J 87:3764-74. 2004

Research Grants

  1. Modeling of chemotactic sensing in Dictyostelium
    Pablo Iglesias; Fiscal Year: 2007
  2. Computational Models of Cell Division
    Douglas N Robinson; Fiscal Year: 2010

Collaborators

Detail Information

Publications50

  1. pmc Quantifying robustness of biochemical network models
    Lan Ma
    Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD USA
    BMC Bioinformatics 3:38. 2002
    ..Robustness of mathematical models of biochemical networks is important for validation purposes and can be used as a means of selecting between different competing models. Tools for quantifying parametric robustness are needed...
  2. pmc Biased excitable networks: how cells direct motion in response to gradients
    Pablo A Iglesias
    Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, United States
    Curr Opin Cell Biol 24:245-53. 2012
    ..In this review, we discuss some of these observations and theories proposed to explain them. We also suggest a mechanism for cell polarity that can be incorporated into the existing framework...
  3. doi request reprint Chemoattractant signaling in dictyostelium: adaptation and amplification
    Pablo A Iglesias
    Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD 21218, USA
    Sci Signal 5:pe8. 2012
    ..Recent quantitative experiments provide support for a popular model: the local excitation, global inhibition mechanism of gradient sensing. Here, I discuss these findings and suggest some important open problems...
  4. pmc A method for determining the robustness of bio-molecular oscillator models
    Reza Ghaemi
    Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA
    BMC Syst Biol 3:95. 2009
    ..Several tools have been proposed in the literature. Unfortunately, multiparameter robustness analysis suffers from computational limitations...
  5. doi request reprint Spatial regulation of PI3K signaling during chemotaxis
    Pablo A Iglesias
    Department of Electrical and Computer Engineering, The Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
    Wiley Interdiscip Rev Syst Biol Med 1:247-53. 2009
    ..We also briefly discuss one model used to elucidate the PI3K pathway...
  6. doi request reprint Navigating through models of chemotaxis
    Pablo A Iglesias
    Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
    Curr Opin Cell Biol 20:35-40. 2008
    ..Mathematical models that have been proposed to explain chemotaxis typically focus on only one of these processes. We summarize the strengths and weaknesses of the models and point out the need for an integrated model...
  7. doi request reprint A systems biology view of adaptation in sensory mechanisms
    Pablo A Iglesias
    Department of Electrical and Computer Engineering, The Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA
    Adv Exp Med Biol 736:499-516. 2012
    ..While most of these models have been used to study chemoattractant-induced responses in bacteria and amoebae, the system-theoretic issues associated with these systems are of importance in a broad spectrum of biological systems...
  8. pmc tsunami, the Dictyostelium homolog of the Fused kinase, is required for polarization and chemotaxis
    Linnan Tang
    Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
    Genes Dev 22:2278-90. 2008
    ..Thus, localization of kinase activity to microtubules is critical for TsuA function. We propose that functions in association with the microtubule network may underlie the divergent roles of Fused kinase proteins in different organisms...
  9. pmc Automated characterization of cell shape changes during amoeboid motility by skeletonization
    Yuan Xiong
    Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
    BMC Syst Biol 4:33. 2010
    ....
  10. pmc Two complementary, local excitation, global inhibition mechanisms acting in parallel can explain the chemoattractant-induced regulation of PI(3,4,5)P3 response in dictyostelium cells
    Lan Ma
    Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
    Biophys J 87:3764-74. 2004
    ..Finally, we use the model to predict the response of a cell where only a fraction is stimulated by a saturating dose of chemoattractant...
  11. pmc A mechanosensory system governs myosin II accumulation in dividing cells
    Yee Seir Kee
    Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
    Mol Biol Cell 23:1510-23. 2012
    ..Overall, this mechanosensory system is structured like a control system characterized by mechanochemical feedback loops that regulate myosin II localization at sites of mechanical stress and the cleavage furrow...
  12. pmc Deconvolution of the cellular force-generating subsystems that govern cytokinesis furrow ingression
    Christopher C Poirier
    Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
    PLoS Comput Biol 8:e1002467. 2012
    ..Our simulations highlight the relative contributions of different biomechanical subsystems to cell shape progression during cell division...
  13. pmc Understanding the cooperative interaction between myosin II and actin cross-linkers mediated by actin filaments during mechanosensation
    Tianzhi Luo
    Department of Cell Biology, The Johns Hopkins University, Baltimore, Maryland, USA
    Biophys J 102:238-47. 2012
    ..This mechanism is likely to be general for a range of myosin II-dependent cellular mechanosensory processes...
  14. pmc Dynacortin facilitates polarization of chemotaxing cells
    Cathryn Kabacoff
    Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
    BMC Biol 5:53. 2007
    ..Dynacortin also becomes highly enriched in cortical protrusions, which are sites of new actin assembly...
  15. pmc Mitotic membrane helps to focus and stabilize the mitotic spindle
    Christopher C Poirier
    Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD, USA
    Biophys J 99:3182-90. 2010
    ..We show that an elastic membrane around the mitotic apparatus helps to focus MT minus ends and provides a resistive force that acts antagonistically to plus-end-directed MT motors such as Eg5...
  16. pmc Mechanosensing through cooperative interactions between myosin II and the actin crosslinker cortexillin I
    Yixin Ren
    Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
    Curr Biol 19:1421-8. 2009
    ..For a myosin motor to experience tension, the actin filament must also be anchored...
  17. doi request reprint PIP3-independent activation of TorC2 and PKB at the cell's leading edge mediates chemotaxis
    Yoichiro Kamimura
    Department of Cell Biology, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
    Curr Biol 18:1034-43. 2008
    ..However, chemotaxis can still occur in the absence of PIP(3), and the identities of the PIP(3)-independent pathways remain unknown...
  18. pmc Chemoattractant-induced phosphatidylinositol 3,4,5-trisphosphate accumulation is spatially amplified and adapts, independent of the actin cytoskeleton
    Chris Janetopoulos
    Department of Cell Biology, Johns Hopkins University School of Medicine, 725 North Wolfe Street, Baltimore, MD 21205, USA
    Proc Natl Acad Sci U S A 101:8951-6. 2004
    ..These results support a local excitation/global inhibition model and argue against other schemes proposed to explain directional sensing...
  19. pmc Modeling cellular deformations using the level set formalism
    Liu Yang
    Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
    BMC Syst Biol 2:68. 2008
    ..Here we demonstrate that accurate cell shape changes can be recreated using level set methods (LSM), in which the cellular shape is defined implicitly, thereby eschewing the need for updating boundaries...
  20. pmc An information-theoretic characterization of the optimal gradient sensing response of cells
    Burton W Andrews
    Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, Maryland, United States of America
    PLoS Comput Biol 3:e153. 2007
    ..Our results demonstrate that different observed classes of responses in cells (polarized and unpolarized) are optimal under varying information assumptions...
  21. pmc Molecular mechanisms of cellular mechanosensing
    Tianzhi Luo
    Department of Cell Biology, Johns Hopkins University, Baltimore, Maryland 21205, USA
    Nat Mater 12:1064-71. 2013
    ..Our observations show that the accumulation kinetics of each protein may be explained by its molecular mechanisms, and that protein accumulation and the cell's viscoelastic state can explain cell contraction against mechanical load. ..
  22. pmc Regulation of SREBP during hypoxia requires Ofd1-mediated control of both DNA binding and degradation
    Joshua R Porter
    Department of Electrical and Computer Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
    Mol Biol Cell 23:3764-74. 2012
    ..This model quantifies our understanding of a novel oxygen-sensing mechanism that is widely conserved...
  23. pmc PLA2 and PI3K/PTEN pathways act in parallel to mediate chemotaxis
    Lingfeng Chen
    Department of Cell Biology, Johns Hopkins University, School of Medicine, Baltimore, MD 21205, USA
    Dev Cell 12:603-14. 2007
    ..We propose that PLA(2) and PI3K signaling act in concert to mediate chemotaxis, and metabolites of PLA(2) may be important mediators of the response...
  24. pmc Interactions between myosin and actin crosslinkers control cytokinesis contractility dynamics and mechanics
    Elizabeth M Reichl
    Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
    Curr Biol 18:471-80. 2008
    ..Discerning how this integrated network operates is essential for understanding cytokinesis contractility and shape control. Here, we analyzed the cytoskeletal network that drives furrow ingression in Dictyostelium...
  25. doi request reprint Tools for analyzing cell shape changes during chemotaxis
    Yuan Xiong
    Department of Electrical and Computer Engineering, The Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA
    Integr Biol (Camb) 2:561-7. 2010
    ..Here we review recent developments in the tracking and understanding of motile chemotaxing cells, with a particular emphasis on the description of pseudopodial activity in chemotactic Dictyostelium cells...
  26. pmc 14-3-3 coordinates microtubules, Rac, and myosin II to control cell mechanics and cytokinesis
    Qiongqiong Zhou
    Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
    Curr Biol 20:1881-9. 2010
    ..However, what these signals are and how they lead to the spatiotemporal changes in the cortex structure, mechanics, and regional contractility are not well understood in any system...
  27. doi request reprint A framework for designing and analyzing binary decision-making strategies in cellular systems
    Joshua R Porter
    Department of Electrical and Computer Engineering, The Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA
    Integr Biol (Camb) 4:310-7. 2012
    ..As proof of concept, we use the framework to quantify the goals of the externally triggered apoptosis pathway...
  28. pmc Identifying a static nonlinear structure in a biological system using noisy, sparse data
    Joshua R Porter
    Department of Electrical and Computer Engineering, Johns Hopkins University, 105 Barton Hall, 3400 N Charles Street, Baltimore, MD 21218, USA
    J Theor Biol 300:232-41. 2012
    ..Simulations with this model produced outputs consistent with experimental observations. The techniques introduced here will provide researchers with a new tool by which biological systems can be identified and characterized...
  29. ncbi request reprint Chemoattractant signaling in dictyostelium discoideum
    Carol L Manahan
    Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
    Annu Rev Cell Dev Biol 20:223-53. 2004
    ..The modules and connections represent current understanding, and future information is expected to modify and build upon this structure...
  30. pmc Spatial regulation improves antiparallel microtubule overlap during mitotic spindle assembly
    Wilbur E Channels
    Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
    Biophys J 94:2598-609. 2008
    ..Finally, we show that limiting the diffusion of motor complexes within the spindle region increases antiparallel microtubule interaction...
  31. ncbi request reprint A mechanosensory system controls cell shape changes during mitosis
    Janet C Effler
    Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
    Cell Cycle 6:30-5. 2007
    ..In this review, we summarize these findings and their implications for cytokinesis regulation and for understanding the cytoskeletal system architecture that governs shape control...
  32. pmc Cells navigate with a local-excitation, global-inhibition-biased excitable network
    Yuan Xiong
    Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
    Proc Natl Acad Sci U S A 107:17079-86. 2010
    ..Our study brings together heretofore diverse observations on spontaneous cytoskeletal activity, signaling responses to temporal stimuli, and spatial gradient sensing into a unified scheme...
  33. pmc Interaction of motility, directional sensing, and polarity modules recreates the behaviors of chemotaxing cells
    Changji Shi
    Department of Electrical and Computer Engineering, Whiting School of Engineering, Johns Hopkins University, Baltimore, Maryland, USA
    PLoS Comput Biol 9:e1003122. 2013
    ..Finally, by varying the strengths of various feedback loops in the model we obtain cellular behaviors that mirror those of genetically altered cell lines...
  34. pmc Dynamic properties of network motifs contribute to biological network organization
    Robert J Prill
    Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA
    PLoS Biol 3:e343. 2005
    ..We propose that robust dynamical stability is an influential property that can determine the non-random structure of biological networks...
  35. pmc Separation anxiety: stress, tension and cytokinesis
    Krithika Mohan
    Department of Electrical and Computer Engineering, The Johns Hopkins University, 3400 N Charles Street, Baltimore, MD 21218, USA
    Exp Cell Res 318:1428-34. 2012
    ..We also describe a mechanosensory feedback control system that regulates protein localization and shape progression during cytokinesis...
  36. pmc Lineage mapping the pre-implantation mouse embryo by two-photon microscopy, new insights into the segregation of cell fates
    Katie McDole
    Department of Biology, Johns Hopkins University, 3400 N Charles St, Baltimore, MD 21218, USA
    Dev Biol 355:239-49. 2011
    ..Our studies provide a framework for the future use of specific markers to track cell fate molecularly and with high accuracy...
  37. ncbi request reprint Local excitation, global inhibition mechanism for gradient sensing: an interactive applet
    Brett Kutscher
    Department of Electrical and Computer Engineering, Johns Hopkins University, 3400 North Charles Street, 226 Barton Hall, Baltimore, MD 21218, USA
    Sci STKE 2004:pl3. 2004
    ..To illustrate this general mechanism, we have developed an interactive applet that mimics laboratory experiments in which either spatially homogeneous or heterogeneous stimuli of chemoattractant are applied...
  38. ncbi request reprint Coordination of chromosome alignment and mitotic progression by the chromosome-based Ran signal
    Hoi Y Li
    Department of Embryology, Carnegie Institution of Washington and Howard Hughes Medical Institute, Baltimore, Maryland, USA
    Cell Cycle 6:1886-95. 2007
    ..Our spatial simulation of RanGTP production using individual chromosomes should provide means to further understand how the Ran system and the cell cycle machinery coordinately regulate mitosis...
  39. pmc Optimal noise filtering in the chemotactic response of Escherichia coli
    Burton W Andrews
    Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, Maryland, United States of America
    PLoS Comput Biol 2:e154. 2006
    ..This paper furnishes a simple quantitative framework for interpreting many of the key notions about bacterial chemotaxis, and, more generally, it highlights the constraints on biological systems imposed by noise...
  40. pmc Mitosis-specific mechanosensing and contractile-protein redistribution control cell shape
    Janet C Effler
    Department of Cell Biology, Johns Hopkins University School of Medicine, 725 N Wolfe Street, Baltimore, Maryland 21205, USA
    Curr Biol 16:1962-7. 2006
    ..Our data provide evidence for a mechanosensory system that directs contractile proteins to regulate cell shape during mitosis...
  41. ncbi request reprint MAPK-mediated bimodal gene expression and adaptive gradient sensing in yeast
    Saurabh Paliwal
    Department of Biomedical Engineering and Whitaker Institute of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
    Nature 446:46-51. 2007
    ..In addition, the dynamic range of gradient sensing of Kss1-deficient cells was reduced compared with wild type. We thus provide unsuspected functional significance for this kinase in regulation of the mating response...
  42. doi request reprint Modeling spatial and temporal dynamics of chemotactic networks
    Liu Yang
    Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD, USA
    Methods Mol Biol 571:489-505. 2009
    ..Computer simulations have proved to be useful in testing conceptual models. Here we outline the steps required to develop these models...
  43. pmc Excitable behavior in amoeboid chemotaxis
    Changji Shi
    Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, MD, USA
    Wiley Interdiscip Rev Syst Biol Med 5:631-42. 2013
    ....
  44. doi request reprint Nucleating new branches from old
    Yixian Zheng
    Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
    Cell 152:669-70. 2013
    ..Using total internal reflection fluorescent microscopy and Xenopus egg extracts, Petry et al. demonstrate that new microtubules can also nucleate and branch out from existing ones in animal cells...
  45. pmc Bringing the physical sciences into your cell biology research
    Douglas N Robinson
    Department of Cell Biology and Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
    Mol Biol Cell 23:4167-70. 2012
    ..This effort requires an interdisciplinary approach by investigators from both the biological and the physical sciences...
  46. ncbi request reprint An integrative approach to understanding mechanosensation
    Christopher C Poirier
    Department of Electrical and Computer Engineering, The Johns Hopkins University, 3400North Charles Street, Baltimore, MD 21218, USA
    Brief Bioinform 8:258-65. 2007
    ..Multiscale modeling methods combined with experimental techniques in an integrative approach are suggested as ways of undertaking the study of such systems...
  47. pmc Ergosterol regulates sterol regulatory element binding protein (SREBP) cleavage in fission yeast
    Joshua R Porter
    Department of Electrical and Computer Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
    J Biol Chem 285:41051-61. 2010
    ..Based on this relationship, we predict that the Sre1-Scp1 complex exists under "active" and "inactive" states and that the transition between these states is cooperatively mediated by ergosterol...
  48. ncbi request reprint Modeling the cell's guidance system
    Pablo A Iglesias
    Department of Electrical and Computer Engineering, Johns Hopkins University, 105 Barton Hall, Baltimore, MD 21218, USA
    Sci STKE 2002:re12. 2002
    ..We also propose a way to view chemotaxis regulation as a highly coupled combination of semi-independent control modules, leading to simplifying modeling of this complex cellular behavior...
  49. ncbi request reprint Control analysis of bacterial chemotaxis signaling
    Tau Mu Yi
    Department of Developmental and Cell Biology, Center for Complex Biological Systems, Irvine, California, USA
    Methods Enzymol 422:123-40. 2007
    ..This chapter describes some basic principles of control theory relevant to the analysis of this sensing system, including sensitivity analysis, Bode plots, integral feedback control, and noise filters (i.e., Kalman filters)...
  50. pmc Models of eukaryotic gradient sensing: application to chemotaxis of amoebae and neutrophils
    Andre Levchenko
    Divisions of Biology, California Institute of Technology, Pasadena, California 91125, USA
    Biophys J 82:50-63. 2002
    ..We propose that the underlying principles of perfect adaptation and substrate supply-based positive feedback will be found in the sensory systems of other chemotactic cell types...

Research Grants5

  1. Modeling of chemotactic sensing in Dictyostelium
    Pablo Iglesias; Fiscal Year: 2007
    ....
  2. Computational Models of Cell Division
    Douglas N Robinson; Fiscal Year: 2010
    ..In this research we combine computational and experimental tools to study the way that cells regulate their mechanical properties to ensure that each mother cells successfully divides into two equally-sized daughter cells. ..