These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: New mode of DNA binding of multi-zinc finger transcription factors: deltaEF1 family members bind with two hands to two target sites.
    Author: Remacle JE, Kraft H, Lerchner W, Wuytens G, Collart C, Verschueren K, Smith JC, Huylebroeck D.
    Journal: EMBO J; 1999 Sep 15; 18(18):5073-84. PubMed ID: 10487759.
    Abstract:
    SIP1, a Smad-interacting protein, and deltaEF1, a transcriptional repressor involved in skeletal and T-cell development, belong to the same family of DNA binding proteins. SIP1 and deltaEF1 contain two separated clusters of zinc fingers, one N-terminal and one C-terminal. These clusters show high sequence homology and are highly conserved between SIP1 and deltaEF1. Each zinc finger cluster binds independently to a 5'-CACCT sequence. However, high-affinity binding sites for full-length SIP1 and deltaEF1 in the promoter regions of candidate target genes like Xenopus Xbra2, and human alpha4-integrin and E-cadherin, are bipartite elements composed of one CACCT and one CACCTG sequence, the orientation and spacing of which can vary. Using transgenic Xenopus embryos, we demonstrate that the integrity of these two sequences is necessary for correct spatial expression of a Xbra2 promoter-driven reporter gene. Both zinc finger clusters must be intact for the high-affinity binding of SIP1 to DNA and for its optimal repressor activity. Our results show that SIP1 binds as monomer and contacts one target sequence with the first zinc finger cluster, and the other with the second cluster. Our work redefines the optimal binding site and, consequently, candidate target genes for vertebrate members of the deltaEF1 family.
    [Abstract] [Full Text] [Related] [New Search]