Dynamical basis of cellular sensing and responsiveness to spatial-temporal signals

dc.contributor.advisorKoseska, Aneta
dc.contributor.authorNandan, Akhilesh Padmanabhan
dc.contributor.refereeBastiaens, Philippe
dc.date.accepted2022-03-15
dc.date.accessioned2023-02-22T07:01:04Z
dc.date.available2023-02-22T07:01:04Z
dc.date.issued2022
dc.description.abstractUnder physiological conditions, cells continuously sense and migrate in response to chemoattractant signals that are noisy, conflicting, and changing over time and space. This suggests cells exhibit seemingly opposed characteristics, such as robust maintenance of polarized state longer than the signal duration, while still remaining adaptive to novel signals. However, the dynamical mechanism that enables such sensing capabilities is still unclear. In this thesis, I propose a generic dynamical mechanism based on critical positioning of receptor signaling network in the vicinity of saddle-node of a sub-critical pitchfork bifurcation (SubPB mechanism). The critical organization leads to the emergence of a dynamical "ghost" that gives transient memory in the polarized response, as well as the ability to continuously adapt to changes in signal localization. Using weakly nonlinear analysis, an analytical description of the necessary conditions for the existence of this mechanism in a general receptor network is provided. Comparing to three classes of existing mathematical models for polarization that operate on the principle of stable attractors, I demonstrate that the metastability arising from "ghost" in the SubPB mechanism uniquely enables sensing dynamic spatial-temporal signals in a history-dependent manner. By using a physical model that couples signaling to morphology, I demonstrate how this mechanism enables cells to navigate in changing environments. Using the well characterized Epidermal growth factor receptor (EGFR) sensing network in epithelial cells, I demonstrated that the described transient memory in signaling mimics working memory in neurons, enabling cells to process non-stationary signals.en
dc.identifier.urihttp://hdl.handle.net/2003/41255
dc.identifier.urihttp://dx.doi.org/10.17877/DE290R-23096
dc.language.isoende
dc.subjectCell polarizationen
dc.subjectResponsiveness to changing signalsen
dc.subjectDynamical "ghost" statesen
dc.subjectTransient metastable dynamicsen
dc.subjectCriticalityen
dc.subjectSubcritical pitchfork bifurcationen
dc.subject.ddc570
dc.subject.ddc540
dc.subject.rswkEpidermal growth factoren
dc.subject.rswkZellkommunikationde
dc.titleDynamical basis of cellular sensing and responsiveness to spatial-temporal signalsen
dc.typeTextde
dc.type.publicationtypedoctoralThesisde
dcterms.accessRightsopen access
eldorado.secondarypublicationfalsede

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