1: EMBO J. 1998 Mar 2;17(5):1423-33. 

Prep1, a novel functional partner of Pbx proteins.

Berthelsen J, Zappavigna V, Mavilio F, Blasi F.

Dipartimento di Genetica e Biologia dei Microrganismi dell'Universita, DIBIT,
H.S. Raffaele, via Olgettina 58, 20132, Milan, Italy.

The human transcription factor, UEF3, is important in regulating the activity of
the urokinase plasminogen activator (uPA) gene enhancer. The UEF3 DNA target
site is a regulatory element in the promoters of several growth factor and
protease genes. We reported previously that purified UEF3 is a complex of
several subunits. In this paper we report the cloning of the cDNA of one of the
subunits which encodes for a novel human homeodomain protein, which we have
termed Prep1. The Prep1 homeodomain belongs to the TALE class of homeodomains,
is most closely related to those of the TGIF and Meis1 proteins, and like these,
recognizes a TGACAG motif. We further identify the other UEF3 subunit as a
member of the Pbx protein family. Unlike other proteins known to interact with
Pbx, Prep1 forms a stable complex with Pbx independent of DNA binding.
Heterodimerization of Prep1 and Pbx results in a strong DNA binding affinity
towards the TGACAG target site of the uPA promoter. Overall, these data indicate
that Prep1 is a stable intracellular partner of Pbx in vivo.

PMID: 9482739 [PubMed - indexed for MEDLINE]


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