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Loss of Lamin A leads to the nuclear translocation of AGO2 and compromised RNA interference

Affiliations
  • 1Department of Medical Biochemistry and Cell biology, Institute of Biomedicine, University of Gothenburg, SE-40530 Gothenburg, Sweden.
  • 2Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, SE-40530 Gothenburg, Sweden.
  • 3Department of Biochemistry and Biophysics, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Stockholm University, Box 1031, SE-17121 Solna, Sweden.
  • 4Department of Microbiology and Immunology, Institute of Biomedicine, University of Gothenburg, SE-40530 Gothenburg, Sweden.
  • 5Biomedical Research Centre, University Hospital Hradec Kralove, Sokolska 581, 500 05 Hradec Kralove, Czech Republic.
  • 6Lab of Cellular RNA Biology, The Shmunis School of Biomedicine and Cancer Research, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel.
  • 7SciLifeLab, Institute of Biomedicine, University of Gothenburg, SE-40530 Gothenburg, Sweden.

Published on:

July 12, 2024

Abstract

In mammals, RNA interference (RNAi) was historically studied as a cytoplasmic event; however, in the last decade, a growing number of reports convincingly show the nuclear localization of the Argonaute (AGO) proteins. Nevertheless, the extent of nuclear RNAi and its implication in biological mechanisms remain to be elucidated. We found that reduced Lamin A levels significantly induce nuclear influx of AGO2 in SHSY5Y neuroblastoma and A375 melanoma cancer cell lines, which normally have no nuclear AGO2. Lamin A KO manifested a more pronounced effect in SHSY5Y cells compared to A375 cells, evident by changes in cell morphology, increased cell proliferation, and oncogenic miRNA expression. Moreover, AGO fPAR-CLIP in Lamin A KO SHSY5Y cells revealed significantly reduced RNAi activity. Further exploration of the nuclear AGO interactome by mass spectrometry identified FAM120A, an RNA-binding protein and known interactor of AGO2. Subsequent FAM120A fPAR-CLIP, revealed that FAM120A co-binds AGO targets and that this competition reduces the RNAi activity. Therefore, loss of Lamin A triggers nuclear AGO2 translocation, FAM120A mediated RNAi impairment, and upregulation of oncogenic miRNAs, facilitating cancer cell proliferation.

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