Projects per year
Genetic tags allow rapid localization of tagged proteins in cells and tissues. APEX, an ascorbate peroxidase, has proven to be one of the most versatile and robust genetic tags for ultrastructural localization by electron microscopy (EM). Here, we describe a simple method, APEX-Gold, which converts the diffuse oxidized diaminobenzidine reaction product of APEX into a silver/ gold particle akin to that used for immunogold labelling. The method increases the signal-to-noise ratio for EM detection, providing unambiguous detection of the tagged protein, and creates a readily quantifiable particulate signal. We demonstrate the wide applicability of this method for detection of membrane proteins, cytoplasmic proteins, and cytoskeletal proteins. The method can be combined with different EM techniques including fast freezing and freeze substitution, focussed ion beam scanning EM, and electron tomography. Quantitation of expressed APEX-fusion proteins is achievable using membrane vesicles generated by a cell-free expression system. These membrane vesicles possess a defined quantum of signal, which can act as an internal standard for determination of the absolute density of expressed APEX-fusion proteins. Detection of fusion proteins expressed at low levels in cells from CRISPR-edited mice demonstrates the high sensitivity of the APEX-Gold method.
1/01/19 → 31/12/23
Davis, T., Boyd, B., Bunnett, N., Porter, C., Caruso, F., Kent, S., Thordarson, P., Kearnes, M., Gooding, J., Kavallaris, M., Thurecht, K., Whittaker, A. K., Parton, R., Corrie, S. R., Johnston, A., McGhee, J., Greguric, I. D., Stevens, M. M., Lewis, J., Lee, D. S., Alexander, C., Dawson, K., Hawker, C., Haddleton, D., Thierry, B., Prestidge, C. A., Meyer, A., Jones-Jayasinghe, N., Voelcker, N. H., Nann, T. & McLean, K.
Australian Research Council (ARC), Monash University, University of Melbourne, University of New South Wales (UNSW), University of Queensland , University of South Australia, Monash University – Internal Faculty Contribution, University of Wisconsin Madison, Memorial Sloan Kettering Cancer Center, University of California System, University College Dublin, Imperial College London, University of Warwick, SungKyunKwan University, Australian Nuclear Science and Technology Organisation (ANSTO) , University of Nottingham
30/06/14 → 29/06/21