title: Relevance of intracellular polarity to accuracy of eukaryotic chemotaxis.
abstract: Eukaryotic chemotaxis is usually mediated by intracellular signals that tend to localize at the front or back of the cell. Such intracellular polarities frequently require no extracellular guidance cues, indicating that spontaneous polarization occurs in the signal network. Spontaneous polarization activity is considered relevant to the persistent motions in random cell migrations and chemotaxis. In this study, we propose a theoretical model that connects spontaneous intracellular polarity and motile ability in a chemoattractant solution. We demonstrate that the intracellular polarity can enhance the accuracy of chemotaxis. Chemotactic accuracy should also depend on chemoattractant concentration through the concentration-dependent correlation time in the polarity direction. Both the polarity correlation time and the chemotactic accuracy depend on the degree of responsiveness to the chemical gradient. We show that optimally accurate chemotaxis occurs at an intermediate responsiveness of intracellular polarity. Experimentally, we find that the persistence time of randomly migrating Dictyostelium cells depends on the chemoattractant concentration, as predicted by our theory. At the optimum responsiveness, this ameboid cell can enhance its chemotactic accuracy tenfold.
authors.affiliation: Center for Developmental Biology, RIKEN, Chuo-ku, Kobe, Hyogo, Japan. Japan Science and Technology Agency, CREST, 1-3 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hiraiwa
authors.forename: Akihiro
authors.initials: A
authors.lastname: Nagamatsu
authors.forename: Naohiro
authors.initials: N
authors.lastname: Akuzawa
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Nishikawa
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Shibata
mesh_terms: D002465:Cell Movement; D016764:Cell Polarity; D002630:Chemotactic Factors / Q000494:pharmacology*; D002633:Chemotaxis; D003593:Cytoplasm / Q000502:physiology; D004023:Dictyostelium / Q000502:physiology*; D008954:Models, Biological
chemical_list: D002630:Chemotactic Factors