Chicken beta B1-crystallin gene expression: presence of conserved functional polyomavirus enhancer-like and octamer binding-like promoter elements found in non-lens genes.

During lens fiber cell differentiation, the regulation of crystallin gene expression is coupled with dramatic morphological changes. Here we report that Mafs, Prox1, and Pax6, which are essential transcription factors for normal lens development, bind to three functionally important cis elements, PL1, PL2, and OL2, in the chicken ␤B1-crystallin promoter and may cooperatively direct the transcription of this lens fiber cell preferred gene. Gel shift assays demonstrated that Mafs bind to the MARE-like sequences in the PL1 and PL2 elements, whereas Prox1, a sequence-specific DNA-binding protein like its Drosophila homolog Prospero, interacts with the OL2 element. Furthermore, Pax6, a known repressor of the chicken ␤B1-crystallin promoter, binds to all three of these cis elements. In transfection assays, Mafs and Prox1 activated the chicken ␤B1-crystallin promoter; however, their transactivation ability was repressed when co-transfected with Pax6. Taken together with the known spatiotemporal expression patterns of Mafs, Prox1, and Pax6 in the developing lens, we propose that Pax6 occupies and represses the chicken ␤B1-crystallin promoter in lens epithelial cells, and is displaced by Prox1 and Mafs, which activate the promoter, in differentiating cortical fiber cells.

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“…1A) (39). Site-directed mutagenesis of PL1 (M6A) and PL2 (M7) decrease chicken ␤B1-crystallin promoter activity (39).…”

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confidence: 99%

Mafs, Prox1, and Pax6 Can Regulate Chicken βB1-Crystallin Gene Expression

Cui

Tomarev

Piatigorsky

et al. 2004

Journal of Biological Chemistry

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“…With regard to the ␤B1-crystallin gene, promoters of the mouse, chicken, and Xenopus have been investigated by in vitro or in vivo experiments (Roth et al, 1991;Duncan et al, 1995bDuncan et al, , 1996Chen et al, 2001;Cui et al, 2004;Mizuno et al, 2005). Likewise, results of those studies suggest that multiple regulators are implicated in gene regulation.…”

Section: Discussionmentioning

confidence: 99%

“…A number of potential regulatory elements comprising two Sp1 sites, two octamerbinding sequence-like sites (OL-1 and OL-2), and two polymavirus enhancer-like sites (PL-1 and PL-2, marked in Fig. 6A) were identified in the proximal region (Ϫ126/Ϫ53 bp) by in vitro analysis, showing that PL-1 seems to be a general activating element, whereas PL-2 is involved in lens specificity (Roth et al, 1991;Duncan et al, 1996). In vivo transgenic studies showed that the upstream regions of chicken (434 bp) and mouse (1,493 bp) ␤B1-crystallin are functional in the mouse (Duncan et al, 1995b(Duncan et al, , 1996Chen et al, 2001).…”

Section: Discussionmentioning

confidence: 99%

“…6A). Interestingly, the six-base pair core sequence (TGATGA) is included in the PL-1 and PL-2 elements of chicken and Xenopus ␤B1-crystallins (Roth et al, 1991;Mizuno et al, 2005; shown in Fig. 6A).…”

Section: Discussionmentioning

confidence: 99%

“…4B), corresponding to a sequence conserved in the ␤B1-crystallin promoter of other species (see Fig. 6A; den Dunnen et al, 1986;Roth et al, 1991). This located start site is situated 26 bp downstream of the putative TATA box and begins with an A residue (see Fig.…”

Section: Determination Of the Transcriptional Initiation Site Of The mentioning

confidence: 99%

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Recapitulation of human βB1‐crystallin promoter activity in transgenic zebrafish

Hou

Kuo

Luo

et al. 2005

Developmental Dynamics

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Development of the eye is morphologically similar among vertebrates, indicating that the underlying mechanism regulating the process may have been highly conserved during evolution. Herein we analyzed the promoter of the human ␤B1-crytallin gene in zebrafish by transgenic experiments. To delineate the evolutionarily conserved regulatory elements, we performed serial deletion assays in the promoter region. The results demonstrated that the ؊90/؉61-bp upstream proximal promoter region is sufficient to confer lens-tissue specificity to the human ␤B1-crystallin gene in transgenic zebrafish. Through phylogenetic sequence comparisons and an electrophoretic mobility shift assay (EMSA), a highly conserved cis-element of a six-base pair sequence TG(A/C)TGA, the consensus sequence for the Maf protein binding site, within the proximal promoter region was revealed. Further, a site-mutational assay showed that this element is crucial for promoter activity. These data suggest that the fundamental transcriptional regulatory mechanism of the ␤B1-crystallin gene has been well conserved between humans and zebrafish, and plausibly among all vertebrates, during evolution. Developmental Dynamics 235:435-443, 2006.

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Molecular analyses of carbonic anhydrase‐II expression and regulation in the developing chicken lens

Buono

Linser

Cuthbertson

et al. 1992

Developmental Dynamics

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The expression of carbonic anhydrase-I1 (CA-11) in the developing chicken lens was examined and compared with that in the retina of the chicken embryo. CA-I1 expression was measured by immunohistochemistry and radioimmunoassay during development, and CA-I1 mRNA was quantified by Northern blot and densitometric scanning and localized by in situ hybridization. A functional promoter of the chicken CA-I1 gene was identified by transfection of primary embryonic chicken lens epithelial cells and analyzed in deletion mutants. The results establish that CA-I1 makes u p about 0.1% of the total soluble protein of the embryonic chicken lens, an amount insufficient to make it a candidate for an enzyme crystallin in this species. Lens fiber differentiation coincided with a loss of CA-I1 mRNA and protein; by contrast, CA-I1 persisted in the epithelial cells of the embryonic and mature lens. This and previous studies showed that CA-I1 amounts to as much as 3% of the protein of the embryonic chicken retina and follows a different developmental time course of expression; like the lens, CA-I1 decreases until day 10 in the embryonic retina, but, unlike the lens, it increases thereafter and plateaus at hatching. Progressive deletions of the 5' flanking regions (from position -1314 to +32) of the CA-I1 gene fused to the bacterial chloramphenicol acetyltransferase (CAT) reporter gene resulted in a gradual loss of promoter activity, consistent with an additive effect of putative cis-regulatory elements found in many crystallin genes. These experiments provide the foundation for a molecular analysis of the developmental and differential regulation of the CA-I1 gene in lens and retina. o 1992 Wiley-Liss, Inc.

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Chicken beta B1-crystallin gene expression: presence of conserved functional polyomavirus enhancer-like and octamer binding-like promoter elements found in non-lens genes.

Cited by 53 publications

References 51 publications

Mafs, Prox1, and Pax6 Can Regulate Chicken βB1-Crystallin Gene Expression

Mafs, Prox1, and Pax6 Can Regulate Chicken βB1-Crystallin Gene Expression

Recapitulation of human βB1‐crystallin promoter activity in transgenic zebrafish

Molecular analyses of carbonic anhydrase‐II expression and regulation in the developing chicken lens

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