Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.

Functionally distinct isoforms of the CRE-BP DNA-binding protein mediate activity of a T-cell-specific enhancer.

Georgopoulos K., Morgan B.A., Moore D.D.

Expression of the CD3 delta gene of the T-cell receptor (TCR) complex is regulated by a T-cell-specific enhancer. A highly conserved 40-bp motif (element delta A) within the CD3 delta enhancer is responsible for mediating its activity and specificity. Element delta A exhibits sequence similarities to the cyclic AMP response element (CRE) but does not respond to changes in the level of cyclic AMP. Using the delta A element as a probe, we have isolated three cDNA clones encoding three distinct protein isoforms, products of differential splicing and alternate promoter usage of the CRE-BP gene. These isoforms share the DNA binding and dimerization domains at the C terminus of the protein but differ at their N termini. In transfection assays, their activities as transcription regulators differ: CRE-BP2 is a potent activator, CRE-BP3 is a weak activator, and CRE-BP1 is transcriptionally inert. Mutations in the basic region of the CRE-BP1 protein which abrogate its ability to bind DNA render this protein a dominant repressor of the delta A enhancer. Antibodies to the CRE-BP protein interact specifically with the ubiquitous and predominantly T-cell-restricted nuclear complexes that bind to the delta A element and suggest the presence of this protein in homo- and heterodimeric complexes. Since the delta A motif is also present in the enhancer and promoter of the TCR alpha and beta genes, the CRE-BP isoforms may mediate expression of other members of the CD3/TCR complex during T-cell development.

Mol. Cell. Biol. 12:747-757(1992) [PubMed] [Europe PMC]

We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.

Do not show this banner again
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health