Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we will assume that you are happy to receive all cookies and you will not see this message again. Click 'Find out more' for information on how to change your cookie settings.

The enzymatic activity of the three most studied bacterial toxins that increase the cytosolic cAMP level: pertussis toxin (PT), cholera toxin (CT), and anthrax edema toxin (ET), was imaged by fluorescence videomicroscopy. Three different cell lines were transfected with a fluorescence resonance energy transfer biosensor based on the PKA regulatory and catalytic subunits fused to CFP and YFP, respectively. Real-time imaging of cells expressing this cAMP biosensor provided time and space resolved pictures of the toxins action. The time course of the PT-induced cAMP increase suggests that its active subunit enters the cytosol more rapidly than that deduced by biochemical experiments. ET generated cAMP concentration gradients decreasing from the nucleus to the cell periphery. On the contrary, CT, which acts on the plasma membrane adenylate cyclase, did not. The potential of imaging methods in studying the mode of entry and the intracellular action of bacterial toxins is discussed.

Original publication

DOI

10.1016/j.bbrc.2008.09.012

Type

Journal article

Journal

Biochem Biophys Res Commun

Publication Date

14/11/2008

Volume

376

Pages

429 - 433

Keywords

Adenylyl Cyclases, Antigens, Bacterial, Bacterial Toxins, Cell Line, Cell Membrane, Cholera Toxin, Cyclic AMP, Cytosol, Fluorescence Resonance Energy Transfer, Fluorescent Dyes, Humans, Microscopy, Fluorescence, Pertussis Toxin