XB-ART-6399Proc Natl Acad Sci U S A. October 29, 2002; 99 (22): 14320-5.
The LIM-domain-binding protein Ldb1 is a key factor in the assembly of transcriptional complexes involving LIM-homeodomain proteins and other transcription factors that regulate animal development. We identified Ssdp proteins (previously described as sequence-specific, single-stranded-DNA-binding proteins) as components of Ldb1-associated nuclear complexes in HeLa cells. Ssdp proteins are associated with Ldb1 in a variety of additional mammalian cell types. This association is specific, does not depend on the presence of nucleic acids, and is functionally significant. Genes encoding Ssdp proteins are well conserved in evolution from Drosophila to humans. Whereas the vertebrate Ssdp gene family has several closely related members, the Drosophila Ssdp gene is unique. In Xenopus, Ssdp encoded by Drosophila Ssdp or mouse Ssdp1 mRNA enhances axis induction by Ldb1 in conjunction with the LIM-homeobox gene Xlim1. Furthermore, we were able to demonstrate an interaction between Ssdp and Chip (the fly homolog of Ldb1) in Drosophila wing development. These findings indicate functional conservation of Ssdp as a cofactor of Ldb1 during invertebrate and vertebrate development.
PubMed ID: 12381786
PMC ID: PMC137882
Article link: Proc Natl Acad Sci U S A.
Genes referenced: ldb1 lhx1 ssbp3
Article Images: [+] show captions
|Fig 3. Examples of Xenopus embryos injected at the four-cell stage and photographed at stage 35/36. Different combinations of mRNAs, in amounts listed individually below, were injected into the prospective ventral marginal zone. (A) 100 pg mSsdp1; (B) 40 pg Xlim1, 40 pg Xldb1; (C) 400 pg Xlim1, 400 pg Xldb1; (D and E) 40 pg Xlim1, 40 pg Xldb1, 100 pg mSsdp1; (F) 40 pg Xlim1, 40 pg Xldb1, 100 pg dSsdp. In C–F, examples of embryos that did show secondary axes are illustrated; the percentages of embryos showing this phenotype are listed in Table 1.|