FACT subunit Spt16 controls UVSSA recruitment to lesion-stalled RNA Pol II and stimulates TC-NER

Nucleic Acids Res. 2019 May 7;47(8):4011-4025. doi: 10.1093/nar/gkz055.


Transcription-coupled nucleotide excision repair (TC-NER) is a dedicated DNA repair pathway that removes transcription-blocking DNA lesions (TBLs). TC-NER is initiated by the recognition of lesion-stalled RNA Polymerase II by the joint action of the TC-NER factors Cockayne Syndrome protein A (CSA), Cockayne Syndrome protein B (CSB) and UV-Stimulated Scaffold Protein A (UVSSA). However, the exact recruitment mechanism of these factors toward TBLs remains elusive. Here, we study the recruitment mechanism of UVSSA using live-cell imaging and show that UVSSA accumulates at TBLs independent of CSA and CSB. Furthermore, using UVSSA deletion mutants, we could separate the CSA interaction function of UVSSA from its DNA damage recruitment activity, which is mediated by the UVSSA VHS and DUF2043 domains, respectively. Quantitative interaction proteomics showed that the Spt16 subunit of the histone chaperone FACT interacts with UVSSA, which is mediated by the DUF2043 domain. Spt16 is recruited to TBLs, independently of UVSSA, to stimulate UVSSA recruitment and TC-NER-mediated repair. Spt16 specifically affects UVSSA, as Spt16 depletion did not affect CSB recruitment, highlighting that different chromatin-modulating factors regulate different reaction steps of the highly orchestrated TC-NER pathway.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism
  • Cell Cycle Proteins / genetics*
  • Cell Cycle Proteins / metabolism
  • Cell Line, Transformed
  • Cell Line, Tumor
  • Chromatin / metabolism
  • Chromatin / ultrastructure
  • DNA / genetics*
  • DNA / metabolism
  • DNA Breaks, Double-Stranded
  • DNA Helicases / genetics
  • DNA Helicases / metabolism
  • DNA Repair Enzymes / genetics
  • DNA Repair Enzymes / metabolism
  • DNA Repair*
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Fibroblasts / metabolism
  • Fibroblasts / ultrastructure
  • Genes, Reporter
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • HEK293 Cells
  • High Mobility Group Proteins / genetics*
  • High Mobility Group Proteins / metabolism
  • Humans
  • Optical Imaging
  • Osteoblasts / metabolism
  • Osteoblasts / ultrastructure
  • Poly-ADP-Ribose Binding Proteins / genetics
  • Poly-ADP-Ribose Binding Proteins / metabolism
  • Protein Binding
  • Protein Domains
  • Protein Transport
  • RNA Polymerase II / genetics*
  • RNA Polymerase II / metabolism
  • Transcription Factors / genetics*
  • Transcription Factors / metabolism
  • Transcription, Genetic*
  • Transcriptional Elongation Factors / genetics*
  • Transcriptional Elongation Factors / metabolism


  • Carrier Proteins
  • Cell Cycle Proteins
  • Chromatin
  • DNA-Binding Proteins
  • ERCC8 protein, human
  • High Mobility Group Proteins
  • Poly-ADP-Ribose Binding Proteins
  • SSRP1 protein, human
  • SUPT16H protein, human
  • Transcription Factors
  • Transcriptional Elongation Factors
  • UVSSA protein, human
  • Green Fluorescent Proteins
  • DNA
  • RNA Polymerase II
  • DNA Helicases
  • ERCC6 protein, human
  • DNA Repair Enzymes