qSR: a quantitative super-resolution analysis tool reveals the cell-cycle dependent organization of RNA Polymerase I in live human cells

Sci Rep. 2018 May 9;8(1):7424. doi: 10.1038/s41598-018-25454-0.


We present qSR, an analytical tool for the quantitative analysis of single molecule based super-resolution data. The software is created as an open-source platform integrating multiple algorithms for rigorous spatial and temporal characterizations of protein clusters in super-resolution data of living cells. First, we illustrate qSR using a sample live cell data of RNA Polymerase II (Pol II) as an example of highly dynamic sub-diffractive clusters. Then we utilize qSR to investigate the organization and dynamics of endogenous RNA Polymerase I (Pol I) in live human cells, throughout the cell cycle. Our analysis reveals a previously uncharacterized transient clustering of Pol I. Both stable and transient populations of Pol I clusters co-exist in individual living cells, and their relative fraction vary during cell cycle, in a manner correlating with global gene expression. Thus, qSR serves to facilitate the study of protein organization and dynamics with very high spatial and temporal resolutions directly in live cell.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Benzothiazoles / pharmacology
  • Cell Cycle*
  • Cell Line, Tumor
  • Cell Survival
  • Data Analysis*
  • Enzyme Assays / methods*
  • Humans
  • Naphthyridines / pharmacology
  • RNA Polymerase I / metabolism*
  • Software*
  • Transcription, Genetic / drug effects


  • Benzothiazoles
  • CX 5461
  • Naphthyridines
  • RNA Polymerase I