scholarly journals Stimulation of Pol III-dependent 5S rRNA and U6 snRNA gene expression by AP-1 transcription factors

FEBS Journal ◽  
2017 ◽  
Vol 284 (13) ◽  
pp. 2066-2077 ◽  
Author(s):  
Richa Ahuja ◽  
Vijay Kumar
1992 ◽  
Vol 175 (5) ◽  
pp. 1327-1336 ◽  
Author(s):  
C Go ◽  
J Miller

T cell activation requires two distinct signals. The first is delivered through the antigen-specific T cell receptor (TCR), and the second is provided by costimulatory molecule(s) present on the surface of the antigen-presenting cell (APC). Stimulation of T helper type 1 T cell clones through the TCR in the absence of the costimulatory activity results in a lack of interleukin 2 (IL-2) secretion and proliferation, and the induction of a long-lived state of nonresponsiveness, termed anergy. In this study, we have examined the transcription factors involved in IL-2 gene expression that are expressed after stimulation of normal T cell clones through the TCR with and without engagement of the necessary costimulatory molecule(s). Antigen-specific activation of the clones results in the induction of a similar pattern of transcription factors that have been previously shown to regulate IL-2 expression. In contrast, antigen presentation by chemically fixed APC, a condition that results in T cell anergy, induces neither NF-AT nor one of the two NF-kappa B binding factors. Thus, the failure to express IL-2 during the induction of T cell anergy may be attributed to the absence of these two transcription factors. When anergized T cells are restimulated with antigen and conventional APC, they induce the transcription factors associated with IL-2 expression, but they fail to synthesize measurable IL-2. Taken together, these data indicate that the control of IL-2 gene expression during anergy induction and during normal stimulation of anergized cells are distinct, and suggest the presence of additional regulatory elements in the IL-2 gene.


1994 ◽  
Vol 14 (9) ◽  
pp. 5910-5919
Author(s):  
S Connelly ◽  
C Marshallsay ◽  
D Leader ◽  
J W Brown ◽  
W Filipowicz

RNA polymerase (Pol) II- and RNA Pol III-transcribed small nuclear RNA (snRNA) genes of dicotyledonous plants contain two essential upstream promoter elements, the USE and TATA. The USE is a highly conserved plant snRNA gene-specific element, and its distance from the -30 TATA box, corresponding to approximately three and four helical DNA turns in Pol III and Pol II genes, respectively, is crucial for determining RNA Pol specificity of transcription. Sequences upstream of the USE play no role in snRNA gene transcription in dicot plants. Here we show that for expression of snRNA genes in maize, a monocotyledonous plant, the USE and TATA elements are essential, but not sufficient, for transcription. Efficient expression of both Pol II- and Pol III-specific snRNA genes in transfected maize protoplasts requires an additional element(s) positioned upstream of the USE. This element, named MSP (for monocot-specific promoter; consensus, RGCCCR), is present in one to three copies in monocot snRNA genes and is interchangeable between Pol II- and Pol III-specific genes. The efficiency of snRNA gene expression in maize protoplast is determined primarily by the strength of the MSP element(s); this contrasts with the situation in protoplasts of a dicot plant, Nicotiana plumbaginifolia, where promoter strength is a function of the quality of the USE element. Interestingly, the organization of monocot Pol III-specific snRNA gene promoters closely resembles those of equivalent vertebrate promoters. The data are discussed in the context of the coevolution of Pol II- and Pol III-specific snRNA gene promoters within many eukaryotic organisms.


2022 ◽  
Author(s):  
Shaunak Kar ◽  
Yogendra Bordiya ◽  
Nestor Rodriguez ◽  
Junghyun Kim ◽  
Elizabeth C Gardner ◽  
...  

Abstract Background: The construction and application of synthetic genetic circuits is frequently improved if gene expression can be orthogonally controlled, relative to the host. In plants, orthogonality can be achieved via the use of CRISPR-based transcription factors that are programmed to act on natural or synthetic promoters. The construction of complex gene circuits can require multiple, orthogonal regulatory interactions, and this in turn requires that the full programmability of CRISPR elements be adapted to non-natural and non-standard promoters that have few constraints on their design. Therefore, we have developed synthetic promoter elements in which regions upstream of the minimal 35S CaMV promoter are designed from scratch to interact via programmed gRNAs with dCas9 fusions that allow activation of gene expression. Results: A panel of three, mutually orthogonal promoters that can be acted on by artificial gRNAs bound by CRISPR regulators were designed. Guide RNA expression targeting these promoters was in turn controlled by either Pol III (U6) or ethylene-inducible Pol II promoters, implementing for the first time a fully artificial Orthogonal Control System (OCS). Following demonstration of the complete orthogonality of the designs, the OCS was tied to cellular metabolism by putting gRNA expression under the control of an endogenous plant signaling molecule, ethylene. The ability to form complex circuitry was demonstrated via the ethylene-driven, ratiometric expression of fluorescent proteins in single plants. Conclusions: The design of synthetic promoters is highly generalizable to large tracts of sequence space, allowing Orthogonal Control Systems of increasing complexity to potentially be generated at will. The ability to tie in several different basal features of plant molecular biology (Pol II and Pol III promoters, ethylene regulation) to the OCS demonstrates multiple opportunities for engineering at the system level. Moreover, given the fungibility of the core 35S CaMV promoter elements, the derived synthetic promoters can potentially be utilized across a variety of plant species.


2021 ◽  
Author(s):  
Shaunak Kar ◽  
Yogendra Bordiya ◽  
Nestor Rodriguez ◽  
Jungyun Kim ◽  
Elizabeth C Gardner ◽  
...  

Background: The construction and application of synthetic genetic circuits is frequently improved if gene expression can be orthogonally controlled, relative to the host. In plants, orthogonality can be achieved via the use of CRISPR-based transcription factors that are programmed to act on natural or synthetic promoters. The construction of complex gene circuits can require multiple, orthogonal regulatory interactions, and this in turn requires that the full programmability of CRISPR elements be adapted to non-natural and non-standard promoters that have few constraints on their design. Therefore, we have developed synthetic promoter elements in which regions upstream of the minimal 35S CaMV promoter are designed from scratch to interact via programmed gRNAs with dCas9 fusions that allow activation of gene expression. Results: A panel of three, mutually orthogonal promoters that can be acted on by artificial gRNAs bound by CRISPR regulators were designed. Guide RNA expression targeting these promoters was in turn controlled by either Pol III (U6) or ethylene-inducible Pol II promoters, implementing for the first time a fully artificial Orthogonal Control System (OCS). Following demonstration of the complete orthogonality of the designs, the OCS was tied to cellular metabolism by putting gRNA expression under the control of an endogenous plant signaling molecule, ethylene. The ability to form complex circuitry was demonstrated via the ethylene-driven, ratiometric expression of fluorescent proteins in single plants. Conclusions: The design of synthetic promoters is highly generalizable to large tracts of sequence space, allowing Orthogonal Control Systems of increasing complexity to potentially be generated at will. The ability to tie in several different basal features of plant molecular biology (Pol II and Pol III promoters, ethylene regulation) to the OCS demonstrates multiple opportunities for engineering at the system level. Moreover, given the fungibility of the core 35S CaMV promoter elements, the derived synthetic promoters can potentially be utilized across a variety of plant species.


1994 ◽  
Vol 14 (9) ◽  
pp. 5910-5919 ◽  
Author(s):  
S Connelly ◽  
C Marshallsay ◽  
D Leader ◽  
J W Brown ◽  
W Filipowicz

RNA polymerase (Pol) II- and RNA Pol III-transcribed small nuclear RNA (snRNA) genes of dicotyledonous plants contain two essential upstream promoter elements, the USE and TATA. The USE is a highly conserved plant snRNA gene-specific element, and its distance from the -30 TATA box, corresponding to approximately three and four helical DNA turns in Pol III and Pol II genes, respectively, is crucial for determining RNA Pol specificity of transcription. Sequences upstream of the USE play no role in snRNA gene transcription in dicot plants. Here we show that for expression of snRNA genes in maize, a monocotyledonous plant, the USE and TATA elements are essential, but not sufficient, for transcription. Efficient expression of both Pol II- and Pol III-specific snRNA genes in transfected maize protoplasts requires an additional element(s) positioned upstream of the USE. This element, named MSP (for monocot-specific promoter; consensus, RGCCCR), is present in one to three copies in monocot snRNA genes and is interchangeable between Pol II- and Pol III-specific genes. The efficiency of snRNA gene expression in maize protoplast is determined primarily by the strength of the MSP element(s); this contrasts with the situation in protoplasts of a dicot plant, Nicotiana plumbaginifolia, where promoter strength is a function of the quality of the USE element. Interestingly, the organization of monocot Pol III-specific snRNA gene promoters closely resembles those of equivalent vertebrate promoters. The data are discussed in the context of the coevolution of Pol II- and Pol III-specific snRNA gene promoters within many eukaryotic organisms.


2004 ◽  
Vol 24 (9) ◽  
pp. 3596-3606 ◽  
Author(s):  
Sushma Shivaswamy ◽  
George A. Kassavetis ◽  
Purnima Bhargava

ABSTRACT Transcription of the U6 snRNA gene (SNR6) in Saccharomyces cerevisiae by RNA polymerase III (pol III) requires TFIIIC and its box A and B binding sites. In contrast, TFIIIC has little or no effect on SNR6 transcription with purified components in vitro due to direct recognition of the SNR6 TATA box by TFIIIB. When SNR6 was assembled into chromatin in vitro by use of the Drosophila melanogaster S-190 extract, transcription of these templates with highly purified yeast pol III, TFIIIC, and TFIIIB displayed a near-absolute requirement for TFIIIC but yielded a 5- to 15-fold-higher level of transcription relative to naked DNA (>100-fold activation over repressed chromatin). Analysis of chromatin structure demonstrated that TFIIIC binding leads to remodeling of U6 gene chromatin, resulting in positioning of a nucleosome between boxes A and B. The resulting folding of the intervening DNA into the nucleosome could bring the suboptimally spaced SNR6 box A and B elements into greater proximity and thus facilitate activation of transcription. In the absence of ATP, however, the binding of TFIIIC to box B in chromatin was not accompanied by remodeling and the transcription activation was ∼35% of that seen in its presence, implying that both TFIIIC binding and ATP-dependent chromatin remodeling were required for the full activation of the gene. Our results suggest that TFIIIC, which is a basal transcription factor of pol III, also plays a direct role in remodeling chromatin on the SNR6 gene.


2021 ◽  
Author(s):  
Chanawee Jakkawanpitak ◽  
Masashi Inafuku ◽  
Hirosuke Oku ◽  
Nongporn Hutadilok-Towatana ◽  
Ruthaiwan Bunkrongcheap ◽  
...  

Abstract The dynamic ability of adipocytes in adipose tissue to store lipid in response to changes in the nutritional input and inflammatory elicitors has a major impact on human health. Previously, we established laminarin-coated beads or LCB as an inflammatory elicitor for adipocytes. However, it was not clear whether LCB inhibits lipid accumulation in adipocytes. Here, we show that LCB acts in the early stage of adipogenesis through both IRAK and SYK pathways, resulting in the activation of the AMPK and NF-kB complexes, which subsequently cause cell cycle arrest, suppression of C/EBPb, PPARg, C/EBPa, FAS, FABP4, and ACC proteins, downregulation of other transcription factors and enzymes, such as Pparg, C/ebpa, Srebp-1, Lpl, and Fas gene expression, inhibition of adipogenesis, and stimulation of an inflammatory response. Unlike the inhibition of adipogenesis, LCB could stimulate an inflammatory response at any stage of differentiation. In addition, we find that Tlr2 and Clec7a/Dectin-1 but not Tlr4 and Cd36 gene expression are upregulated upon the treatment with LCB, suggesting that TLR2 and CLEC7A/Dectin-1 might be the b-glucan receptors for the cells. Together, we present the mechanism of LCB, as fungal-like particles, that elicit an inflammatory response and inhibit adipogenesis at the early stage of differentiation.


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