Cloning by recognition site screening of two novel GT box binding proteins: a family of Sp1 related genes.
Previous analyses of the uteroglobin gene promoter revealed a GT1 box which is also found in the SV40 enhancer. The GT1 element in the context of the uteroglobin promoter is active in Ishikawa cells, a human endometrial cell line, but not in HeLa cells. Here we report the cloning by recognition site screening of two factors (SPR-1 and SPR-2) which bind to this GT1 motif. SPR-1 and SPR-2 are homologues of the transcription factor Sp1. All three proteins are closely related members of a gene family encoding proteins with very similar structural features. Like Sp1, SPR-1 and SPR-2 contain glutamine and serine/threonine rich amino acid stretches. Most significantly, the DNA binding domains of all three proteins are highly conserved and they recognize GT as well as GC boxes identically. SPR-2 mRNA is expressed ubiquitously, whereas SPR-1 transcripts are abundant in the brain but barely detectable in other organs. The possible function of these factors for the activity of the uteroglobin promoter is discussed.
Hagen
G
G
Institut für Molekularbiologie und Tumorforschung, Philipps-Universität Marburg, Germany.
Müller
S
S
Beato
M
M
Suske
G
G
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism; D002460:Cell Line; D003001:Cloning, Molecular / Q000379:methods; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D005810:Multigene Family; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011817:Rabbits; D017386:Sequence Homology, Amino Acid; D016329:Sp1 Transcription Factor / Q000235:genetics* / Q000378:metabolism; D051705:Sp3 Transcription Factor; D051706:Sp4 Transcription Factor; D014158:Transcription, Genetic; D014598:Uteroglobin / Q000235:genetics*
D004268:DNA-Binding Proteins; C497124:SP4 protein, human; D016329:Sp1 Transcription Factor; D051706:Sp4 Transcription Factor; C497125:Sp4 protein, mouse; D051705:Sp3 Transcription Factor; D004247:DNA; D014598:Uteroglobin