scholarly journals Novel S. cerevisiae Hybrid Synthetic Promoters Based on Foreign Core Promoter Sequences

2021 ◽  
Vol 22 (11) ◽  
pp. 5704
Author(s):  
Xiaofan Feng ◽  
Mario Andrea Marchisio

Promoters are fundamental components of synthetic gene circuits. They are DNA segments where transcription initiation takes place. New constitutive and regulated promoters are constantly engineered in order to meet the requirements for protein and RNA expression into different genetic networks. In this work, we constructed and optimized new synthetic constitutive promoters for the yeast Saccharomyces cerevisiae. We started from foreign (e.g., viral) core promoters as templates. They are, usually, unfunctional in yeast but can be activated by extending them with a short sequence, from the CYC1 promoter, containing various transcription start sites (TSSs). Transcription was modulated by mutating the TATA box composition and varying its distance from the TSS. We found that gene expression is maximized when the TATA box has the form TATAAAA or TATATAA and lies between 30 and 70 nucleotides upstream of the TSS. Core promoters were turned into stronger promoters via the addition of a short UAS. In particular, the 40 nt bipartite UAS from the GPD promoter can enhance protein synthesis considerably when placed 150 nt upstream of the TATA box. Overall, we extended the pool of S. cerevisiae promoters with 59 new samples, the strongest overcoming the native TEF2 promoter.

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Zhaolian Lu ◽  
Keenan Berry ◽  
Zhenbin Hu ◽  
Yu Zhan ◽  
Tae-Hyuk Ahn ◽  
...  

Abstract Transcription initiation is regulated in a highly organized fashion to ensure proper cellular functions. Accurate identification of transcription start sites (TSSs) and quantitative characterization of transcription initiation activities are fundamental steps for studies of regulated transcriptions and core promoter structures. Several high-throughput techniques have been developed to sequence the very 5′end of RNA transcripts (TSS sequencing) on the genome scale. Bioinformatics tools are essential for processing, analysis, and visualization of TSS sequencing data. Here, we present TSSr, an R package that provides rich functions for mapping TSS and characterizations of structures and activities of core promoters based on all types of TSS sequencing data. Specifically, TSSr implements several newly developed algorithms for accurately identifying TSSs from mapped sequencing reads and inference of core promoters, which are a prerequisite for subsequent functional analyses of TSS data. Furthermore, TSSr also enables users to export various types of TSS data that can be visualized by genome browser for inspection of promoter activities in association with other genomic features, and to generate publication-ready TSS graphs. These user-friendly features could greatly facilitate studies of transcription initiation based on TSS sequencing data. The source code and detailed documentations of TSSr can be freely accessed at https://github.com/Linlab-slu/TSSr.


2017 ◽  
Author(s):  
Sarah Rennie ◽  
Maria Dalby ◽  
Marta Lloret-Llinares ◽  
Stylianos Bakoulis ◽  
Christian Dalager Vaagensø ◽  
...  

ABSTRACTMammalian gene promoters and enhancers share many properties. They are composed of a unified promoter architecture of divergent transcripton initiation and gene promoters may exhibit enhancer function. However, it is currently unclear how expression strength of a regulatory element relates to its enhancer strength and if the unifying architecture is conserved across Metazoa. Here we investigate the transcription initiation landscape and its associated RNA decay in D. melanogaster. Surprisingly, we find that the majority of active gene-distal enhancers and a considerable fraction of gene promoters are divergently transcribed. We observe quantitative relationships between enhancer potential, expression level and core promoter strength, providing an explanation for indirectly related histone modifications that are reflecting expression levels. Lowly abundant unstable RNAs initiated from weak core promoters are key characteristics of gene-distal developmental enhancers, while the housekeeping enhancer strengths of gene promoters reflect their expression strengths. The different layers of regulation mediated by gene-distal enhancers and gene promoters are also reflected in chromatin interaction data. Our results suggest a unified promoter architecture of many D. melanogaster regulatory elements, that is universal across Metazoa, whose regulatory functions seem to be related to their core promoter elements.


2003 ◽  
Vol 384 (9) ◽  
pp. 1287-1292 ◽  
Author(s):  
M. Angermayr ◽  
K. Schwerdtfeger ◽  
W. Bandlow

AbstractRIO1 is an essential gene that encodes a protein serine kinase and is transcribed constitutively at a very low level. Transcriptional activation of RIO1 dispenses with a canonical TATA box as well as with classical transactivators or specific DNA-binding factors. Instead, a dG-dC-rich sequence element, that is located 40 to 48 bp upstream the single site of mRNA initiation, is essential and presumably constitutes the basal promoter. In addition, we demonstrate here that this promoter element comprises a nucleosomefree gap which is centered at the dG-dC tract and flanked by two positioned nucleosomes. This element is both, necessary and sufficient, for basal transcription initiation at the RIO1 promoter and, thus, constitutes a novel type of core promoter element.


2017 ◽  
Author(s):  
Kapil Gupta ◽  
Aleksandra A. Watson ◽  
Tiago Baptista ◽  
Elisabeth Scheer ◽  
Anna L. Chambers ◽  
...  

AbstractGeneral transcription factor TFIID is a key component of RNA polymerase II transcription initiation. Human TFIID is a megadalton-sized complex comprising TATA-binding protein (TBP) and 13 TBP-associated factors (TAFs). TBP binds to core promoter DNA, recognizing the TATA-box. We identified a ternary complex formed by TBP and the histone fold (HF) domain-containing TFIID subunits TAF11 and TAF13. We demonstrate that TAF11/TAF13 competes for TBP binding with TATA-box DNA, and also with the N-terminal domain of TAF1 previously implicated in TATA-box mimicry. In an integrative approach combining crystal coordinates, biochemical analyses and data from cross-linking mass-spectrometry (CLMS), we determine the architecture of the TAF11/TAF13/TBP complex, revealing TAF11/TAF13 interaction with the DNA binding surface of TBP. We identify a highly conserved C-terminal TBP-binding domain (CTID) in TAF13 which is essential for supporting cell growth. Our results thus have implications for cellular TFIID assembly and suggest a novel regulatory state for TFIID function.


Author(s):  
Zhaolian Lu ◽  
Zhenguo Lin

ABSTRACTThe molecular process of transcription by RNA Polymerase II is highly conserved among eukaryotes (“classic model”). Intriguingly, a distinct way of locating transcription start sites (TSSs) was found in a budding yeast Saccharomyces cerevisiae (“scanning model”). The origin of the “scanning model” and its underlying genetic mechanisms remain unsolved. Herein, we applied genomic approaches to address these questions. We first identified TSSs at a single-nucleotide resolution for 12 yeast species using the nAnT-iCAGE technique, which significantly improved the annotations of these genomes by providing accurate 5’boundaries of protein-coding genes. We then infer the initiation mechanism of a species based on its TSS maps and genome sequences. We found that the “scanning model” had originated after the split of Yarrowia lipolytica and the rest of budding yeasts. An adenine-rich region immediately upstream of TSS had appeared during the evolution of the “scanning model” species, which might facilitate TSS selection in these species. Both initiation mechanisms share a strong preference for pyrimidine-purine dinucleotides surrounding the TSS. Our results suggested that the purine is required for accurately recruiting the first nucleotide, increasing the chance of being capped during mRNA maturation, which is critical for efficient translation initiation. Based on our findings, we proposed a model of TSS selection for the “scanning model” species. Besides, our study also demonstrated that the intrinsic sequence feature primarily determines the distribution of initiation activities within a core promoter (core promoter shape).


1998 ◽  
Vol 72 (10) ◽  
pp. 8338-8343 ◽  
Author(s):  
Tricia R. Serio ◽  
Niamh Cahill ◽  
Matthew E. Prout ◽  
George Miller

ABSTRACT During EBV infection, lytic DNA replication activates late gene expression in trans via an uncharacterized pathway. In this study, we mapped the target of this regulatory cascade to a variant TATA box (TATTAAA) and the 3′ flanking region within the core promoter of the BcLF1 gene. The inherent late activity of this core promoter is, surprisingly, disrupted by a heterologous enhancer, suggesting that late gene expression is regulated through core promoter sequences located in a transcriptionally inert environment.


2006 ◽  
Vol 73 ◽  
pp. 225-236 ◽  
Author(s):  
Petra Gross ◽  
Thomas Oelgeschläger

The initiation of mRNA synthesis in eukaryotic cells is a complex and highly regulated process that requires the assembly of general transcription factors and RNAP II (RNA polymerase II; also abbreviated as Pol II) into a pre-initiation complex at the core promoter. The core promoter is defined as the minimal DNA region that is sufficient to direct low levels of activator-independent (basal) transcription by RNAP II in vitro. The core promoter typically extends approx. 40 bp up- and down-stream of the start site of transcription and can contain several distinct core promoter sequence elements. Core promoters in higher eukaryotes are highly diverse in structure, and each core promoter sequence element is only found in a subset of genes. So far, only TATA box and INR (initiator) element have been shown to be capable of directing accurate RNAP II transcription initiation independent of other core promoter elements. Computational analysis of metazoan genomes suggests that the prevalence of the TATA box has been overestimated in the past and that the majority of human genes are TATA-less. While TATA-mediated transcription initiation has been studied in great detail and is very well understood, very little is known about the factors and mechanisms involved in the function of the INR and other core promoter elements. Here we summarize our current understanding of the factors and mechanisms involved in core promoter-selective transcription and discuss possible pathways through which diversity in core promoter architecture might contribute to combinatorial gene regulation in metazoan cells.


2018 ◽  
Author(s):  
Zhaolian Lu ◽  
Zhenguo Lin

AbstractTranscription initiation is finely regulated to ensure the proper expression and function of these genes. The regulated transcription initiation in response to various environmental cues in the model organism Saccharomyces cerevisiae has not been systematically investigated. In this study, we generated quantitative maps of transcription start site (TSS) at a single-nucleotide resolution for S. cerevisiae grown in nine different conditions using no-amplification non-tagging Cap analysis of gene expression (nAnT-iCAGE) sequencing. Based on 337 million uniquely mapped CAGE tags, we mapped ~1 million well-supported TSSs, suggesting highly pervasive transcription initiation in the compact genome of yeast. The comprehensive TSS maps allowed us to identify core promoters for ~96% verified protein-coding genes and to revise the predicted translation start codon for 183 genes. We found that 56% of yeast genes have at least two core promoters and alternative usage of different core promoters in a gene is widespread in response to changing environments. More importantly, most core promoter shifts are coupled with differential gene expression, indicating that core promoter shift might play an important role in controlling transcriptional activity of yeast genes. Based on their dynamic activities, we divided yeast core promoters as constitutive core promoters (55%) and inducible core promoters (45%). The two classes of core promoters exhibit distinctive patterns in transcriptional abundance, chromatin structure, promoter shape, and sequence context. In summary, the quantitative TSS maps generated by this study improved the annotation of yeast genome, and revealed a highly pervasive and dynamic nature of transcription initiation in yeast.


2016 ◽  
Author(s):  
Yun Chen ◽  
Athma A. Pai ◽  
Jan Herudek ◽  
Michal Lubas ◽  
Nicola Meola ◽  
...  

AbstractMammalian transcriptomes are complex and formed by extensive promoter activity. In addition, gene promoters are largely divergent and initiate transcription of reverse-oriented promoter upstream transcripts (PROMPTs). Although PROMPTs are commonly terminated early, influenced by polyadenylation sites, promoters often cluster so that the divergent activity of one might impact another. Here, we find that the distance between promoters strongly correlates with the expression, stability and length of their associated PROMPTs. Adjacent promoters driving divergent mRNA transcription support PROMPT formation, but due to polyadenylation site constraints, these transcripts tend to spread into the neighboring mRNA on the same strand. This mechanism to derive new alternative mRNA transcription start sites (TSSs) is also evident at closely spaced promoters supporting convergent mRNA transcription. We suggest that basic building blocks of divergently transcribed core promoter pairs, in combination with the wealth of TSSs in mammalian genomes, provides a framework with which evolution shapes transcriptomes.


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