DNA topoisomerase I and PC4 can interact with human TFIIIC to promote both accurate termination and transcription reinitiation by RNA polymerase III

Mol Cell. 1998 Apr;1(5):749-57. doi: 10.1016/s1097-2765(00)80074-x.


A human TFIIIC-containing complex (operationally designated holo TFIIIC) has been isolated by immunoaffinity methods and further resolved into two components that are both required for promoter-directed transcription of the VA1 gene. One component, designated TFIIIC, contains 5 polypeptides previously ascribed to TFIIIC2 and 4 additional polypeptides that correspond to TFIIIC1. Included within the other component are factors, namely DNA topoisomerase I and PC4, previously shown to serve as coactivators for transcription by RNA polymerase II. Topoisomerase I and PC4 both enhance TFIIIC interactions with down-stream promoter regions and promote multiple, but not single, round transcription by RNA polymerase III from preformed preinitiation complexes. Novel functions for holo TFIIIC in transcription elongation and accurate termination events that could be important for efficient reinitiation are also described.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Coenzymes / metabolism
  • DNA Footprinting
  • DNA Topoisomerases, Type I / genetics
  • DNA Topoisomerases, Type I / metabolism*
  • HeLa Cells
  • Humans
  • Precipitin Tests
  • Promoter Regions, Genetic / physiology
  • Proprotein Convertases
  • RNA Polymerase III / genetics
  • RNA Polymerase III / metabolism*
  • Serine Endopeptidases / metabolism*
  • Subtilisins
  • Terminator Regions, Genetic / genetics
  • Transcription Factors / isolation & purification
  • Transcription Factors / metabolism*
  • Transcription Factors, TFIII*
  • Transcription, Genetic / physiology*


  • Coenzymes
  • Transcription Factors
  • Transcription Factors, TFIII
  • transcription factor TFIIIC
  • RNA Polymerase III
  • PCSK4 protein, human
  • Proprotein Convertases
  • Serine Endopeptidases
  • Subtilisins
  • DNA Topoisomerases, Type I