Elizabeth Hinde

Elizabeth Hinde

School of Physics, University of Melbourne

Nuclear proteins can modulate their DNA binding activity and the exploration volume available during DNA target search by self-associating into higher order homo-oligomers and formation of hetero-complexes, which exhibit different stoichiometry. Directly tracking this process in the nucleoplasm of a living cell is, however, a complex task. Thus, in recent work we developed a series of fluorescence microscopy methods based on brightness correlation spectroscopy to track the movement of fluorescently tagged nuclear proteins as a function of stoichiometry. By simply performing a rapid single or dual frame scan acquisition, brightness image correlation spectroscopy has the capacity to detect within each pixel, protein homo- or hetero-oligomer formation, and extract the size dependent obstruction nucleus architecture imparts on complex mobility across sub-micron distances. From application of this technology to inert versus biologically active oligomeric transcription factors that form heterocomplexes, we demonstrate protein stoichiometry to differentially regulate chromatin accessibility and interaction with the DNA template