title: Regulation of cell movement is mediated by stretch-activated calcium channels.
abstract: Intracellular calcium regulates many of the molecular processes that are essential for cell movement. It is required for the production of actomyosin-based contractile forces, the regulation of the structure and dynamics of the actin cytoskeletons, and the formation and disassembly of cell-substratum adhesions. Calcium also serves as a second messenger in many biochemical signal-transduction pathways. However, despite the pivotal role of calcium in motile processes, it is not clear how calcium regulates overall cell movement. Here we show that transient increases in intracellular calcium, [Ca2+]i, during the locomotion of fish epithelial keratocytes, occur more frequently in cells that become temporarily 'stuck' to the substratum or when subjected to mechanical stretching. We find that calcium transients arise from the activation of stretch-activated calcium channels, which triggers an influx of extracellular calcium. In addition, the subsequent increase in [Ca2+]i is involved in detachment of the rear cell margin. Thus, we have defined a mechanism by which cells can detect and transduce mechanical forces into biochemical signals that can modulate locomotion.
authors.affiliation: Department of Cell Biology and Anatomy, University of North Carolina, Chapel Hill 27599-7090, USA. jlee@uconnvm.uconn.edu
authors.forename: J
authors.initials: J
authors.lastname: Lee
authors.forename: A
authors.initials: A
authors.lastname: Ishihara
authors.forename: G
authors.initials: G
authors.lastname: Oxford
authors.forename: B
authors.initials: B
authors.lastname: Johnson
authors.forename: K
authors.initials: K
authors.lastname: Jacobson
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000502:physiology*; D002465:Cell Movement / Q000502:physiology*; D048429:Cell Size; D002478:Cells, Cultured; D004548:Elasticity; D006054:Goldfish; D015640:Ion Channel Gating; D008856:Microscopy, Fluorescence; D018715:Microscopy, Video; D011036:Poecilia
chemical_list: D015220:Calcium Channels; D002118:Calcium