Fluorescence lifetime imaging: Association of cortical actin with a PIP3-rich membrane compartment

Konig, I., Schwarz, J. and Anderson, K. (2008) Fluorescence lifetime imaging: Association of cortical actin with a PIP3-rich membrane compartment. European Journal of Cell Biology, 87(8-9), pp. 735-741. (doi: 10.1016/j.ejcb.2008.02.002)

Abstract

We have used fluorescence lifetime imaging (FLIM) to study actin and plasma membrane dynamics in B16-F1 melanoma cells. In the absence of a FRET acceptor, significant changes in the fluorescence lifetime of GFP were induced simply by linking the fluorophore to different functional probes, including beta-actin, the PH domains of PLC delta and Akt, the Ras farnesylation signal, and the neuromodulin palmitoylation signal (MEM). In contrast, the lifetime of GFP-actin was constant despite the many different local environments of G- and F-actin within the cell. Treatment with cytochalasin D but not latrunculin A significantly shortened the lifetime of GFP-beta-actin in the absence of a FRET acceptor. Robust lifetime shifts were observed using either a GFP-RFP chimera or co-transfection of GFP-MEM with RFP-MEM. In contrast to previous reports we observed a photobleaching-dependent change in the lifetime of GFP which could complicate the interpretation of FRET experiments. Of the membrane probes tested only the fluorescence lifetime of GFP-Akt was influenced by the presence of mRFP-actin, suggesting that the cortical actin meshwork is associated with a PIP3-enriched compartment of the plasma membrane. These results will aid in the design of new FRET-based approaches to Study cytoskeletal interactions at the molecular level.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Schwarz, Ms Juliana and Anderson, Professor Kurt and Konig, Ms Ireen
• Authors: Konig, I., Schwarz, J., and Anderson, K.
• College/School: College of Medical Veterinary and Life Sciences > School of Cancer Sciences
• Journal Name: European Journal of Cell Biology
• ISSN: 01719335