CRTR-1, a Developmentally Regulated Transcriptional Repressor Related to the CP2 Family of Transcription Factors

Abstract

CP2-related proteins comprise a family of DNA-binding transcription factors that are generally activators of transcription and expressed ubiquitously. We reported a differential display polymerase chain reaction fragment, Psc2, which was expressed in a regulated fashion in mouse pluripotent cells in vitro and in vivo. Here, we report further characterization of the Psc2 cDNA and function. The Psc2 cDNA contained an open reading frame homologous to CP2 family proteins. Regions implicated in DNA binding and oligomeric complex formation, but not transcription activation, were conserved. Psc2 expression in vivo during embryogenesis and in the adult mouse demonstrated tight spatial and temporal regulation, with the highest levels of expression in the epithelial lining of distal convoluted tubules in embryonic and adult kidneys. Functional analysis demonstrated that PSC2 repressed transcription 2.5-15-fold when bound to a heterologous promoter in ES, 293T, and COS-1 cells. The N-terminal 52 amino acids of PSC2 were shown to be necessary and sufficient for this activity and did not share obvious homology with reported repressor motifs. These results represent the first report of a CP2 family member that is expressed in a developmentally regulated fashion in vivo and that acts as a direct repressor of transcription. Accordingly, the protein has been named CP2-Related Transcriptional Repressor-1 (CRTR-1).

Identification and characterization of Grainyhead‐like epithelial transactivator (GET‐1), a novel mammalian Grainyhead‐like factor

“…In fact, Drosophila Grainyhead has been implicated both in activation (Bray and Kafatos, 1991;Hayashi et al, 1999) and repression of gene expression. The regions of GET-1 capable of repression are not homologous to the repression domain of LBP-9/CRTR-1, which is located between residues 1-52 (Rodda et al, 2001).…”

“…The expression of three mammalian Grainyhead-like genes, CP-2 (Swendeman et al, 1994), LBP-1a (Sueyoshi et al, 1995), and LBP-9 (Huang and Miller, 2000;Rodda et al, 2001), has been characterized, and all are ubiquitously expressed; thus their expression characteristics bear little resemblance to those of Drosophila Grainyhead (Bray et al, 1989;Dynlacht et al, 1989). In contrast, the expression pattern of GET-1, which is prominent in the surface ectoderm and later in epidermis (Figs.…”

“…These are as follows: (1) CP-2 (Lim et al, 1992(Lim et al, , 1993Shirra et al, 1994), also referred to as UBP-1, LSF, LBP-1c, and LBP-1d (alternatively spliced form), a widely expressed transcription factor that has been implicated in activation of the ␣-globin gene (Chodosh et al, 1988;Kim et al, 1990), the HIV-1 long terminal repeat (LTR; Jones et al, 1988;Wu et al, 1988;Malim et al, 1989;Kato et al, 1991), and the SV40 major late promoter (Kim et al, 1987;Huang et al, 1990). This factor can also, depending on context, repress transcription and was shown to cooperate with YY1 to repress HIV-1 LTR activity (Coull et al, 2000); (2) LBP-1a (Sueyoshi et al, 1995), also referred to as LBP-1b (alternatively spliced form) and NF2d9 (Yoon et al, 1994), a widely expressed factor implicated in regulation of the HIV-1 LTR (Yoon et al, 1994) and a P450 gene (Sueyoshi et al, 1995); (3) LBP-9 (Huang and Miller, 2000), also referred to as CP2-related transcriptional Repressor-1 (CRTR-1; Rodda et al, 2001), implicated in regulation of the P450 scc promoter; (4) LBP-32 (Huang and Miller, 2000), also refer- . Grainyhead-like epithelial transactivator 1 (GET-1) transcripts are highly expressed in epithelial cells of the mouse embryo and persist in adult mice.…”

“…Drosophila Grainyhead and mammalian Grainyhead-related transcription factors have been shown to both activate and repress transcription Huang et al, 1995;Liaw et al, 1995;Hayashi et al, 1999;Huang and Miller, 2000;Rodda et al, 2001). To map potential transactivation domains in GET-1, regions of the protein were expressed as fusions with the GAL-4 DNA-binding domain.…”

Gene trap screening as an effective approach for identification of Wnt‐responsive genes in the mouse embryo

“…3A; Rodda et al, 2001). Characterization of a transcript from the clone 43 trapped allele by 5Ј-RACE demonstrated that a fusion transcript had been generated by a splicing between the splicing donor site at the end of exon 2 of CRTR-1 and the engrailed-2 splicing acceptor in the trap vector.…”