Structure-function analysis of the human TFIIB-related factor II protein reveals an essential role for the C-terminal domain in RNA polymerase III transcription.

Hernandez, N.

doi:10.1128/MCB.25.21.9406-9418.2005

Titre

Structure-function analysis of the human TFIIB-related factor II protein reveals an essential role for the C-terminal domain in RNA polymerase III transcription.

Type

article

Institution

UNIL/CHUV/Unisanté + institutions partenaires

Périodique

Molecular and Cellular Biology

Auteur(s)

Saxena, A.

Auteure/Auteur

Ma, B.

Auteure/Auteur

Schramm, L.

Auteure/Auteur

Hernandez, N.

Auteure/Auteur

Liens vers les personnes

Hernandez, Nouria

Liens vers les unités

CIG

Groupe Hernandez

ISSN

0270-7306[print], 0270-7306[linking]

Statut éditorial

Publié

Date de publication

2005

Volume

25

Numéro

21

Première page

9406

Dernière page/numéro d’article

9418

Peer-reviewed

Oui

Langue

anglais

Résumé

The transcription factors TFIIB, Brf1, and Brf2 share related N-terminal zinc ribbon and core domains. TFIIB bridges RNA polymerase II (Pol II) with the promoter-bound preinitiation complex, whereas Brf1 and Brf2 are involved, as part of activities also containing TBP and Bdp1 and referred to here as Brf1-TFIIIB and Brf2-TFIIIB, in the recruitment of Pol III. Brf1-TFIIIB recruits Pol III to type 1 and 2 promoters and Brf2-TFIIIB to type 3 promoters such as the human U6 promoter. Brf1 and Brf2 both have a C-terminal extension absent in TFIIB, but their C-terminal extensions are unrelated. In yeast Brf1, the C-terminal extension interacts with the TBP/TATA box complex and contributes to the recruitment of Bdp1. Here we have tested truncated Brf2, as well as Brf2/TFIIB chimeric proteins for U6 transcription and for assembly of U6 preinitiation complexes. Our results characterize functions of various human Brf2 domains and reveal that the C-terminal domain is required for efficient association of the protein with U6 promoter-bound TBP and SNAP(c), a type 3 promoter-specific transcription factor, and for efficient recruitment of Bdp1. This in turn suggests that the C-terminal extensions in Brf1 and Brf2 are crucial to specific recruitment of Pol III over Pol II.