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Transcriptional activation through the tetrameric complex formation of E4TF1 subunits.
Author(s) -
Sawada J.,
Goto M.,
Sawa C.,
Watanabe H.,
Handa H.
Publication year - 1994
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1994.tb06393.x
Subject(s) - biology , protein subunit , microbiology and biotechnology , genetics , biochemistry , biophysics , gene
Transcription factor E4TF1 is composed of two types of subunit, an ets‐related DNA binding protein, E4TF1‐60, and its associated proteins with four tandemly repeated Notch‐ankyrin motifs, E4TF1‐53 and E4TF1‐47. To determine the functional domains, we constructed various mutants of the subunits. E4TF1‐60 bound to DNA as a monomer. The ets domain and its N‐terminal flanking region were necessary to recognize the specific DNA sequence. The 48 amino acids at the E4TF1‐60 C‐terminus were required for interaction with the other type of subunit. E4TF1‐53 and E4TF1‐47 share the N‐terminal 332 amino acids but differ at the C‐termini. They interacted with E4TF1‐60 through the N‐terminal flanking region to form a heterodimer. E4TF1‐53 dimerized with itself, whereas E4TF1‐47 did not. The C‐terminal region specific for E4TF1‐53 was required for the dimerization. Therefore, heterodimers composed of E4TF1‐53 and E4TF1‐60 were further dimerized, resulting in the formation of a tetrameric complex, which stimulated transcription in vitro. Heterodimers of E4TF1‐47 and E4TF1‐60 weakly stimulated transcription in vitro. The results indicated that the tetrameric complex formation of E4TF1 subunits was necessary to activate transcription efficiently in vitro.