Quantitative analysis of multilayer organization of proteins and RNA in nuclear speckles at super resolution

Jingyi Fei, Mahdieh Jadaliha, Tyler S. Harmon, Isaac T.S. Li, Boyang Hua, Qinyu Hao, Alex S. Holehouse, Matthew Reyer, Qinyu Sun, Susan M. Freier, Rohit V. Pappu, Kannanganattu V. Prasanth, Taekjip Ha

Research output: Contribution to journalArticle

Abstract

Nuclear speckles are self-assembled organelles composed of RNAs and proteins. They are proposed to act as structural domains that control distinct steps in gene expression, including transcription, splicing and mRNA export. Earlier studies identified differential localization of a few components within the speckles. It was speculated that the spatial organization of speckle components might contribute directly to the order of operations that coordinate distinct processes. Here, by performing multi-color structured illumination microscopy, we characterized the multilayer organization of speckles at a higher resolution.We found that SON and SC35 (also known asSRSF2) localize to the central region of the speckle, whereas MALAT1 and small nuclear (sn)RNAs are enriched at the speckle periphery. Coarse-grained simulations indicate that the non-random organization arises due to the interplay between favorable sequenceencoded intermolecular interactions of speckle-resident proteins and RNAs. Finally, we observe positive correlation between the total amount of RNA present within a speckle and the speckle size. These results imply that speckle sizemay be regulated to accommodate RNA accumulation and processing. Accumulation of RNA from various actively transcribed speckle-associated genes could contribute to the observed speckle size variations within a single cell.

Original languageEnglish (US)
Pages (from-to)4180-4192
Number of pages13
JournalJournal of cell science
Volume130
Issue number24
DOIs
StatePublished - Dec 1 2017

    Fingerprint

Keywords

  • Long noncoding RNA
  • Nuclear domain
  • Splicing factor
  • Sub-nuclear compartmentalization

ASJC Scopus subject areas

  • Cell Biology

Cite this

Fei, J., Jadaliha, M., Harmon, T. S., Li, I. T. S., Hua, B., Hao, Q., Holehouse, A. S., Reyer, M., Sun, Q., Freier, S. M., Pappu, R. V., Prasanth, K. V., & Ha, T. (2017). Quantitative analysis of multilayer organization of proteins and RNA in nuclear speckles at super resolution. Journal of cell science, 130(24), 4180-4192. https://doi.org/10.1242/jcs.206854