Progress talk 2 Living cells on the spot: Study of tau dynamics within living neuronal cell models means of photoactivatable constructs

CARINA WEISSMANN

Osnabruck, Alemania

Jornada; 2nd Westerberger Herbsttagung "Molecular Physiology of Neurodegenerative Diseases"; 2004

University of Osnabruck, department of Neurobiology

Progress talk 2 The tau protein, a MAP (Microtubule Associated Protein) principally located on the axon of nerve cells aggregates into intracellular filaments in some neurodegenerative diseases called tauopathies (Brandt, 2001; Shahani and Brandt, 2002). Until this date, most of the studies on the behaviour of this protein were based on in vitro experiments. The aim of this presentation is to introduce the use of the photoactivatable GFP molecule (PAGFP) (Lippincott-Schwartz and Patterson, 2003) to measure the dynamics throughout time of different Tau constructs within living PC12 cells. PC12 cells are derived from a rat pheochromocytoma. Under ordinary culture conditions the cells have properties similar to those of immature rat adrenal chromaffin cells, but when grown in the presence of nerve growth factor (NGF), extend neurites, become electrically excitable, become more responsive to exogenously applied acetylcholine, have increased numbers of calcium channels and increase their synthesis of several neurotransmitters, and therefore resemble sympathetic neurons. Both mutated forms of tau as well as normally expressed isoforms were fused to PAGFP, transfected and expressed in PC12 cells grown in the presence of NGF. Eventually, this approach will assess dynamic parameters for each PAGFP-tau constructs, which will vary as a result of tau interactions with other cell components. A determination of functional interactions of tau constructs in living neuronal cell models could provide important data for understanding tau malfunction during neurodegenerative diseases. This presentation will mostly concentrate on the technical aspects and preliminary results obtained during the initial stage of this project. (supported by the DFG-Graduate College 612) References Brandt, R. (2001) Cytoskeletal mechanisms of neuronal degeneration, Cell & Tissue Research 305:255-265. Lippincott-Schwartz, J., Patterson, G.H. (2003) Development and use of fluorescent potein markers in living cells, Science 300:87-91. Shahani, N., Brandt, R. (2002) Functions and malfunctions of the tau proteins, Cell. Mol. Life Sci. 59:1668-1680.