1: Nucleic Acids Res. 1995 Sep 25;23(18):3732-41. 

Transcription factors RFX1/EF-C and ATF-1 associate with the adenovirus
E1A-responsive element of the human proliferating cell nuclear antigen promoter.

Labrie C, Lee BH, Mathews MB.

Cold Spring Harbor Laboratory, NY 11724-2208, USA.

The proliferating cell nuclear antigen (PCNA) is an adenovirus E1A-inducible
factor that is intimately linked to the processes of DNA replication and cell
cycle regulation. Previously, we defined a novel cis-acting element, the PCNA
E1A-responsive element (PERE), that confers induction by the E1A 243R
oncoprotein upon the human PCNA promoter. To better understand the regulation of
PCNA expression by E1A 243R, we have identified cellular transcription factors
that associate with the PERE. In electrophoretic mobility shift assays, the PERE
formed three major complexes (P1, P2 and P3) with proteins in nuclear extracts
from HeLa or 293 cells. Formation of complexes P2 and P3, which correlates with
PCNA promoter activity in vivo, requires the activating transcription factor
(ATF) binding site found within the PERE [Labrie et al. (1993) Mol. Cell. Biol.,
13, 1697-1707]. Antibody interference experiments and mobility shift assays
performed with in vitro-synthesized protein indicated that the transcription
factor ATF-1 is a major component of these complexes. Similar assays
demonstrated that the hepatitis B virus enhancer-associated protein RFX1
constitutes a major component of the P1 complex. In addition, we examined the
binding of proteins to the minimal E1A-responsive promoter to identify other
factors important for transcription from the PCNA promoter. Mobility shift
assays revealed that a fragment encompassing the region from -87 to +62 relative
to the transcription initiation site forms at least five complexes, EH1-EH5,
with HeLa cell nuclear extracts. The transcription factor YY1 associates with
the initiator element of the PCNA promoter. The identification of these
transcription factors will allow their roles in the activation of PCNA by E1A to
be evaluated.

PMID: 7479004 [PubMed - indexed for MEDLINE]


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