title: Activated membrane patches guide chemotactic cell motility.
abstract: Many eukaryotic cells are able to crawl on surfaces and guide their motility based on environmental cues. These cues are interpreted by signaling systems which couple to cell mechanics; indeed membrane protrusions in crawling cells are often accompanied by activated membrane patches, which are localized areas of increased concentration of one or more signaling components. To determine how these patches are related to cell motion, we examine the spatial localization of RasGTP in chemotaxing Dictyostelium discoideum cells under conditions where the vertical extent of the cell was restricted. Quantitative analyses of the data reveal a high degree of spatial correlation between patches of activated Ras and membrane protrusions. Based on these findings, we formulate a model for amoeboid cell motion that consists of two coupled modules. The first module utilizes a recently developed two-component reaction diffusion model that generates transient and localized areas of elevated concentration of one of the components along the membrane. The activated patches determine the location of membrane protrusions (and overall cell motion) that are computed in the second module, which also takes into account the cortical tension and the availability of protrusion resources. We show that our model is able to produce realistic amoeboid-like motion and that our numerical results are consistent with experimentally observed pseudopod dynamics. Specifically, we show that the commonly observed splitting of pseudopods can result directly from the dynamics of the signaling patches.
authors: Center for Theoretical Biological Physics, University of California San Diego, La Jolla, California, United States of America. inbal.hecht@gmail.com
authors: Inbal
authors: I
authors: Hecht
authors: Monica L
authors: ML
authors: Skoge
authors: Pascale G
authors: PG
authors: Charest
authors: Eshel
authors: E
authors: Ben-Jacob
authors: Richard A
authors: RA
authors: Firtel
authors: William F
authors: WF
authors: Loomis
authors: Herbert
authors: H
authors: Levine
authors: Wouter-Jan
authors: WJ
authors: Rappel
mesh_terms: D002465:Cell Movement / Q000502:physiology*; D002633:Chemotaxis / Q000502:physiology*; D003198:Computer Simulation; D004023:Dictyostelium / Q000166:cytology / Q000502:physiology; D006160:Guanosine Triphosphate; D046210:Microfluidic Analytical Techniques; D008954:Models, Biological; D011554:Pseudopodia / Q000502:physiology*; D015398:Signal Transduction; D059010:Single-Cell Analysis; D018631:ras Proteins
chemical_list: D006160:Guanosine Triphosphate; D018631:ras Proteins