Michèle Milili and Laurent Gauthier contributed equally to this work.
A new Groucho TLE4 protein may regulate the repressive activity of Pax5 in human B lymphocytes
Article first published online: 1 AUG 2002
Volume 106, Issue 4, pages 447–455, August 2002
How to Cite
Milili, M., Gauthier, L., Veran, J., Mattei, M.-G. and Schiff, C. (2002), A new Groucho TLE4 protein may regulate the repressive activity of Pax5 in human B lymphocytes. Immunology, 106: 447–455. doi: 10.1046/j.1365-2567.2002.01456.x
- Issue published online: 1 AUG 2002
- Article first published online: 1 AUG 2002
- Received 7 March 2002; revised 15 April 2002; accepted 26 April 2002.
During mouse B-cell development, Pax5 is an essential transcription factor that acts as an activator of B-cell-specific genes and as a repressor of alternative lineage fates. The repressive function is mediated by the recruitment of members of the Groucho co-repressor family. Using an RNA display approach, we have isolated a transcript, called QD, specifically expressed in human pro-B and pre-B cells, which is derived from the human Groucho TLE4 gene. The QD transcript contains the first four TLE4 exons and an intronic sequence 3′ of exon 4, demonstrating that QD is a splice variant of TLE4. The putative resulting protein of 94 amino acids corresponds to approximately half of an N-terminal tetramerization domain. We also show specific expression of TLE4 transcripts in human B cells and of TLE4 proteins in B-cell nuclei. Moreover, we demonstrate that recombinant QD protein binds to the TLE4 Q domain and is able to abolish the TLE4/Pax5 interaction. Thus, QD could act as a negative regulator of TLE4 function, in early B-cell differentiation.