Genes: Structure and Regulation
Identification, Molecular Cloning, and Characterization of the Sixth Subunit of Human Transcription Factor TFIIIC*

https://doi.org/10.1074/jbc.M611542200Get rights and content
Under a Creative Commons license
open access

TFIIIC in yeast and humans is required for transcription of tRNA and 5 S RNA genes by RNA polymerase III. In the yeast Saccharomyces cerevisiae, TFIIIC is composed of six subunits, five of which are conserved in humans. We report the identification, molecular cloning, and characterization of the sixth subunit of human TFIIIC, TFIIIC35, which is related to the smallest subunit of yeast TFIIIC. Human TFIIIC35 does not contain the phosphoglycerate mutase domain of its yeast counterpart, and these two proteins display only limited homology within a 34-amino acid domain. Homologs of the sixth TFIIIC subunit are also identified in other eukaryotes, and their phylogenic evolution is analyzed. Affinity-purified human TFIIIC from an epitope-tagged TFIIIC35 cell line is active in binding to and in transcription of the VA1 gene in vitro. Furthermore, TFIIIC35 specifically interacts with the human TFIIIC subunits TFIIIC63 and, to a lesser extent, TFIIIC90 in vitro. Finally, we determined a limited region in the smallest subunit of yeast TFIIIC that is sufficient for interacting with the yeast TFIIIC subunit ScTfc1 (orthologous to TFIIIC63) and found it to be adjacent to and overlap the 34-amino acid domain that is conserved from yeast to humans.

Cited by (0)

The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EBI Data Bank with accession number(s) EF137904.

*

This work was supported by a start-up grant from the Conseil Régional d'Aquitaine and the European Regional Development Fund (to M. T.) and by a grant from The Ligue National contre le Cancer (to M. T.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement”in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The on-line version of this article (available at http://www.jbc.org) contains supplemental Table 1.

1

Supported from INSERM E347 by a post-doctoral fellowship from The Ligue National contre le Cancer. Present address: Université Bordeaux 2 Victor Ségalen, 146, rue Léo-Saignat, Bordeaux, F-33076, France.

2

Recipient of a predoctoral fellowship from the Conseil RĂ©gional d'Aquitaine and the Association pour la Recherche contre le Cancer.