Biology subjects

Cella Zanacchi, F.

Publications and source records attributed to Cella Zanacchi, F..

2 recordsLinked to original sources

bioRxiv2023

Super-resolution microscopy reveals the nanoscale organization of the DEK protein cancer biomarker

The chromatin architectural factor DEK is involved in regulating the chromatin organization and is highly overexpressed in numerous forms of cancer. DEK is traditionally described as uniformly distributed within the nucleus by diffraction-limited microscopy studies, but super-resolution advent highlighted the formation of cluster-like DEK structures. Still, a characterization of the DEK protein cellular distribution and its role in cancer and cell proliferation is missing. In this work, we used single-molecule localization microscopy (SMLM) to investigate the nanoscale characteristics of DEK organization in normal-like and aggressive types of breast cancer cell lines, characterizing the number of localizations per cluster, as well as areas and density of clusters. We show how the cluster features correlate with the breast cell type and how the chromatin decompaction influences the DEK clusters in both cell lines. Our results suggest that the DEK density and nano-organization are preserved and are not influenced by protein overexpression itself or by chromatin compaction changes.

biophysics↗

bioRxiv2018

Quantifying motor protein copy number in super-resolution using an imaging invariant calibration

Motor proteins are nanoscale machines that convert the energy of ATP hydrolysis into the mechanical motion of walking along cytoskeletal filaments. In doing so, they transport organelles and help maintain sub-cellular organization. We previously developed a DNA origami-based calibration approach to extract protein copy number from super-resolution images. Using this approach, we show here that the retrograde motor protein dynein is mostly present as a single motor in the cytosol, whereas a small population of dynein along the microtubule cytoskeleton forms higher-order multimers organized into nano-sized domains. We further demonstrate, using dynein as a test sample, that the DNA origami-based calibration data we previously generated can be extended to super-resolution images taken under different experimental conditions, enabling the quantification of any GFP-fused protein of interest. Our results have implications for motor coordination during intracellular trafficking as well as for using super-resolution as a quantitative method to determine protein copy number at the nanoscale level.

biophysics↗