title: Protein and lipid lateral diffusion in normal and Rous sarcoma virus transformed chick embryo fibroblasts.
abstract: We measured the lateral diffusion of the fluorescent lipid analogue dioctadecylindocarbocyanine iodide (DiI) and of membrane glycoproteins labeled with tetramethylrhodamine (TRITC) succinyl concanavalin A (SConA) via fluorescence photobleaching recovery (FPR) at selected times during a temperature downshift experiment on transformation-defective temperature-sensitive (td-ts) Rous sarcoma virus (RSV) NY68-transformed chicken embryo fibroblasts (CEF) and on identically treated CEF and RSV-transformed CEF. There were no significant differences in the lateral diffusion in DiI at any of the times measured. The lateral diffusion of TRITC-SConA on the RSV-transformed CEF, (1.32 +/- 0.12).10(-10) cm2 s-1, was approximately two times faster than that observed in normal CEF, (0.61 +/- 0.06).10(-10) cm2 s-1. In the cells undergoing RSV NY68-mediated transformation, TRITC-SConA diffusion increased over a 24-h period from a value comparable to that observed in normal CEF, (0.72 +/- 0.13).10(-10) cm2 s-1 to a value comparable to the RSV-CEF transformed cells, (1.74 +/- 0.20).10(-10) cm2 s-1. All diffusion measurements reported were made at the permissive temperature for RSV-NY68 (35 degrees C) unless stated otherwise. The changes in the lateral diffusion of TRITC-SConA occurred between the fifth and twelfth hour of the downshift course and could be associated with cytoskeletal disruption and/or fibronectin degradation, both known to occur at this time in RSV-transformed cells. To assess the contribution of extracellular matrix (ECM) degradation, SConA mobility was measured in normal and RSV-transformed cells treated with trypsin. This treatment increased SConA mobility approximately 4-fold in the normal cells relative to untreated controls and only 2-fold in the RSV-CEF transformed cells. No significant difference in SConA mobility between trypsinized spherical normal and transformed cells was apparent.
authors.affiliation: Edward A. Doisy Department of Biochemistry, St. Louis University School of Medicine, MO.
authors.forename: J A
authors.initials: JA
authors.lastname: Boullier
authors.forename: J S
authors.initials: JS
authors.lastname: Peacock
authors.forename: D A
authors.initials: DA
authors.lastname: Roess
authors.forename: B G
authors.initials: BG
authors.lastname: Barisas
mesh_terms: D000818:Animals; D001358:Avian Sarcoma Viruses / Q000502:physiology; D002232:Carbocyanines; D002472:Cell Transformation, Viral / Q000502:physiology*; D002478:Cells, Cultured; D002642:Chick Embryo; D003208:Concanavalin A; D004058:Diffusion; D005347:Fibroblasts / Q000378:metabolism; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008563:Membrane Lipids / Q000378:metabolism*; D012235:Rhodamines; D013696:Temperature
chemical_list: D002232:Carbocyanines; D008562:Membrane Glycoproteins; D008563:Membrane Lipids; D012235:Rhodamines; C075456:tetramethylrhodamine isothiocyanate-conjugated succinyl concanavalin A; D003208:Concanavalin A; C024286:3,3'-dioctadecylindocarbocyanine