XB-ART-22124Mol Cell Biol October 1, 1993; 13 (10): 6479-89.
XrpFI, an amphibian transcription factor composed of multiple polypeptides immunologically related to the GA-binding protein alpha and beta subunits, is differentially expressed during Xenopus laevis development.
XrpFI, first identified in the extract of Xenopus laevis oocyte nuclei, binds to a proximal sequence of the L14 ribosomal protein gene promoter. Its target sequence, 5''-TAACCGGAAGTTTGT-3'', is required to fully activate the promoter, and the two G''s of the central motif are essential for factor binding and transcriptional activation; our data also suggest that XrpFI may play a role in cap site positioning. The binding site of XrpFI is homologous to the sequence recognized by the family of ets genes. Antibodies specific for Ets-1 and Ets-2 proteins did not react with XrpFI, but those raised against the rat alpha and beta GA-binding proteins both supershifted the retarded bands formed by XrpFI. The Xenopus polypeptides related to GA-binding protein alpha interact with DNA both as monomers and as heterodimers associated with beta-related proteins. Oocyte nuclei contain multiple forms of alpha- and beta-related proteins: the alpha-like proteins remain throughout development, while the pattern of the beta species changes in the embryonic stages examined. beta-like proteins are undetectable in the cleavage period up to the neurula stage, but at later stages, when ribosomal protein genes are actively transcribed, two beta-related polypeptides reappear.
PubMed ID: 8413247
PMC ID: PMC364707
Article link: Mol Cell Biol
Species referenced: Xenopus
Genes referenced: ets1 ets2 gabpa
References [+] :
BROWN, RNA SYNTHESIS DURING THE DEVELOPMENT OF XENOPUS LAEVIS, THE SOUTH AFRICAN CLAWED TOAD. 1964, Pubmed, Xenbase