scholarly journals Transcription initiation mapping in 31 bovine tissues reveals complex promoter activity, pervasive transcription, and tissue-specific promoter usage

2020 ◽  
Author(s):  
D.E. Goszczynski ◽  
M.M. Halstead ◽  
A.D. Islas-Trejo ◽  
H. Zhou ◽  
P.J. Ross
Keyword(s):  
Transcription Initiation ◽  
Promoter Activity ◽  
Bovine Genome ◽  
Transcription Start ◽  
Protein Coding ◽  
Tissue Specific ◽  
Transcription Start Sites ◽  
Expression Control ◽  
Tissue Specific Promoter ◽  
Genome Annotations

ABSTRACTCharacterizing transcription start sites is essential for understanding the regulatory mechanisms that control gene expression. Recently, a new bovine genome assembly (ARS-UCD1.2) with high continuity, accuracy, and completeness was released; however, the functional annotation of the bovine genome lacks precise transcription start sites and includes a low number of transcripts in comparison to human and mouse. Using the RAMPAGE approach, this study identified transcription start sites at high resolution in a large collection of bovine tissues. We found several known and novel transcription start sites attributed to promoters of protein coding and lncRNA genes that were validated through experimental and in silico evidence. With these findings, the annotation of transcription start sites in cattle reached a level comparable to the mouse and human genome annotations. In addition, we identified and characterized transcription start sites for antisense transcripts derived from bidirectional promoters, potential lncRNAs, mRNAs, and pre-miRNAs. We also analyzed the quantitative aspects of RAMPAGE data for producing a promoter activity atlas, reaching highly reproducible results comparable to traditional RNA-Seq. Lastly, gene co-expression networks revealed an impressive use of tissue-specific promoters, especially between brain and testicle, which expressed several genes in common from alternate transcription start sites. Regions surrounding co-expressed modules were enriched in binding factor motifs representative of their tissues. This annotation will be highly useful for future studies on expression control in cattle and other species. Furthermore, these data provide significant insight into transcriptional activity for a comprehensive set of tissues.

scholarly journals Expression of murine muscle-enriched A-type lamin-interacting protein (MLIP) is regulated by tissue-specific alternative transcription start sites

2018 ◽  
Vol 293 (51) ◽  
pp. 19761-19770
Author(s):  
Marie-Elodie Cattin ◽  
Shelley A. Deeke ◽  
Sarah A. Dick ◽  
Zachary J. A. Verret-Borsos ◽  
Gayashan Tennakoon ◽  
...  
Keyword(s):  
Transcription Start ◽  
Interacting Protein ◽  
Tissue Specific ◽  
Transcription Start Sites ◽  
Alternative Transcription ◽  
Specific Alternative

scholarly journals Opine-Based Agrobacterium Competitiveness: Dual Expression Control of the Agrocinopine Catabolism (acc) Operon by Agrocinopines and Phosphate Levels

2008 ◽  
Vol 190 (10) ◽  
pp. 3700-3711 ◽  
Author(s):  
H. Stanley Kim ◽  
Hyojeong Yi ◽  
Jaehee Myung ◽  
Kevin R. Piper ◽  
Stephen K. Farrand
Keyword(s):  
Plant Cells ◽  
Regulatory System ◽  
Food Sources ◽  
Competitive Environment ◽  
Operon Structure ◽  
Transcription Start ◽  
Transcription Start Sites ◽  
Expression Control ◽  
Maximum Utilization ◽  
Dual Expression

ABSTRACT Agrobacterium tumefaciens strain C58 can transform plant cells to produce and secrete the sugar-phosphate conjugate opines agrocinopines A and B. The bacterium then moves in response to the opines and utilizes them as exclusive sources of carbon, energy, and phosphate via the functions encoded by the acc operon. These privileged opine-involved activities contribute to the formation of agrobacterial niches in the environment. We found that the expression of the acc operon is induced by agrocinopines and also by limitation of phosphate. The main promoter is present in front of the first gene, accR, which codes for a repressor. This operon structure enables efficient repression when opine levels are low. The promoter contains two putative operators, one overlapping the −10 sequence and the other in the further upstream from it; two partly overlapped putative pho boxes between the two operators; and two consecutive transcription start sites. DNA fragments containing either of the operators bound purified repressor AccR in the absence of agrocinopines but not in the presence of the opines, demonstrating the on-off switch of the promoter. Induction of the acc operon can occur under low-phosphate conditions in the absence of agrocinopines and further increases when the opines also are present. Such opine-phosphate dual regulatory system of the operon may ensure maximum utilization of agrocinopines when available and thereby increase the chances of agrobacterial survival in the highly competitive environment with limited general food sources.

scholarly journals The histone variant H2A.Z in yeast is almost exclusively incorporated into the +1 nucleosome in the direction of transcription

2019 ◽  
Author(s):  
Dia N Bagchi ◽  
Anna M Battenhouse ◽  
Daechan Park ◽  
Vishwanath R Iyer
Keyword(s):  
Transcriptional Activation ◽  
Transcription Initiation ◽  
General Feature ◽  
Antisense Transcription ◽  
Histone Variant ◽  
Expression Data ◽  
Transcription Start ◽  
Chromatin Remodelers ◽  
Transcription Start Sites ◽  
Bidirectional Transcription

Abstract Transcription start sites (TSS) in eukaryotes are characterized by a nucleosome-depleted region (NDR), which appears to be flanked upstream and downstream by strongly positioned nucleosomes incorporating the histone variant H2A.Z. H2A.Z associates with both active and repressed TSS and is important for priming genes for rapid transcriptional activation. However, the determinants of H2A.Z occupancy at specific nucleosomes and its relationship to transcription initiation remain unclear. To further elucidate the specificity of H2A.Z, we determined its genomic localization at single nucleosome resolution, as well as the localization of its chromatin remodelers Swr1 and Ino80. By analyzing H2A.Z occupancy in conjunction with RNA expression data that captures promoter-derived antisense initiation, we find that H2A.Z’s bimodal incorporation on either side of the NDR is not a general feature of TSS, but is specifically a marker for bidirectional transcription, such that the upstream flanking −1 H2A.Z-containing nucleosome is more appropriately considered as a +1 H2A.Z nucleosome for antisense transcription. The localization of H2A.Z almost exclusively at the +1 nucleosome suggests that a transcription-initiation dependent process could contribute to its specific incorporation.

scholarly journals A selector of transcription initiation in the protozoan parasite Toxoplasma gondii.

1995 ◽  
Vol 15 (1) ◽  
pp. 87-93 ◽  
Author(s):  
D Soldati ◽  
J C Boothroyd
Keyword(s):  
Toxoplasma Gondii ◽  
Gene Transcription ◽  
Transcription Initiation ◽  
Protozoan Parasite ◽  
Intracellular Parasite ◽  
Transcription Start ◽  
Transcription Start Sites ◽  
Obligate Intracellular ◽  
Obligate Intracellular Parasite ◽  
Sag1 Gene

The recent development of an efficient transfection system for the apicomplexan Toxoplasma gondii allows a comprehensive dissection of the elements involved in gene transcription in this obligate intracellular parasite. We demonstrate here that for the SAG1 gene, a stretch of six repeated sequences in the region 35 to 190 bp upstream of the first of two transcription start sites is essential for efficient and accurate transcription initiation. This repeat element shows characteristics of a selector in determining the position of the transcription start sites.

scholarly journals The origin and evolution of a distinct mechanism of transcription initiation in yeasts

2020 ◽  
Author(s):  
Zhaolian Lu ◽  
Zhenguo Lin
Keyword(s):  
Rna Polymerase Ii ◽  
Transcription Initiation ◽  
Core Promoter ◽  
Model Species ◽  
Initiation Mechanism ◽  
Protein Coding ◽  
Origin And Evolution ◽  
Transcription Start Sites ◽  
Mrna Maturation ◽  
Nucleotide Resolution

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).

scholarly journals The NSL complex mediated nucleosome landscape is required to maintain transcription fidelity and suppression of transcription noise

2018 ◽  
Author(s):  
Kin Chung Lam ◽  
Ho-Ryun Chung ◽  
Giuseppe Semplicio ◽  
Vivek Bhardwaj ◽  
Shantanu S. Iyer ◽  
...  
Keyword(s):  
Transcription Initiation ◽  
Dependent Manner ◽  
Gene Promoters ◽  
Transcription Start ◽  
Transcription Start Sites ◽  
Chromatin Remodeling Complex ◽  
Selection For ◽  
Necessary And Sufficient ◽  
Target Promoters ◽  
Active Genes

AbstractNucleosomal organization at gene promoters is critical for transcription, with a nucleosome-depleted region (NDR) at transcription start sites (TSSs) being required for transcription initiation. How NDR and the precise positioning of the +1 nucleosome is maintained on active genes remains unclear. Here, we report that the Drosophila Non-Specific Lethal (NSL) complex is necessary to maintain this stereotypical nucleosomal organization at promoters. Upon NSL1 depletion, nucleosomes invade the NDRs at TSSs of NSL-bound genes. NSL complex member NSL3 binds to TATA-less promoters in a sequence-dependent manner. The NSL complex interacts with the NURF chromatin remodeling complex and is necessary and sufficient to recruit NURF to target promoters. The NSL complex is not only essential for transcription but is required for accurate TSS selection for genes with multiple TSSs. Further, loss of NSL complex leads to an increase in transcriptional noise. Thus, the NSL complex establishes a canonical nucleosomal organization that enables transcription and determines TSS fidelity.

scholarly journals Semi-supervised segmentation and genome annotation

2020 ◽  
Author(s):  
Rachel C.W. Chan ◽  
Matthew McNeil ◽  
Eric G. Roberts ◽  
Mickaël Mendez ◽  
Maxwell W. Libbrecht ◽  
...  
Keyword(s):  
Supervised Learning ◽  
Prior Knowledge ◽  
Genome Annotation ◽  
Whole Genome ◽  
Transcription Start ◽  
Transcription Start Sites ◽  
Annotation Method ◽  
Supervised Segmentation ◽  
Unseen Data ◽  
Genome Annotations

AbstractSegmentation and genome annotation methods automatically discover joint signal patterns in whole genome datasets. Previously, researchers trained these algorithms in a fully unsupervised way, with no prior knowledge of the functions of particular regions. Adding information provided by expert-created annotations to supervise training could improve the annotations created by these methods. We implemented semi-supervised learning using virtual evidence in the annotation method Segway. Additionally, we defined a positionally tolerant precision and recall metric for scoring genome annotations based on the proximity of each annotation feature to the truth set. We demonstrate semi-supervised Segway’s ability to learn patterns corresponding to provided transcription start sites on a specified supervision label, and subsequently recover other transcription start sites in unseen data on the same supervision label.

scholarly journals RNA polymerase II-independent recruitment of SPT6L at transcription start sites in Arabidopsis

2019 ◽  
Vol 47 (13) ◽  
pp. 6714-6725 ◽  
Author(s):  
Chen Chen ◽  
Jie Shu ◽  
Chenlong Li ◽  
Raj K Thapa ◽  
Vi Nguyen ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Transcription Initiation ◽  
Elongation Factor ◽  
Proper Function ◽  
Gene Body ◽  
Transcription Start ◽  
Transcription Start Sites ◽  
Genome Wide ◽  
Yeast Mutants

Abstract SPT6 is a conserved elongation factor that is associated with phosphorylated RNA polymerase II (RNAPII) during transcription. Recent transcriptome analysis in yeast mutants revealed its potential role in the control of transcription initiation at genic promoters. However, the mechanism by which this is achieved and how this is linked to elongation remains to be elucidated. Here, we present the genome-wide occupancy of Arabidopsis SPT6-like (SPT6L) and demonstrate its conserved role in facilitating RNAPII occupancy across transcribed genes. We also further demonstrate that SPT6L enrichment is unexpectedly shifted, from gene body to transcription start site (TSS), when its association with RNAPII is disrupted. Protein domains, required for proper function and enrichment of SPT6L on chromatin, are subsequently identified. Finally, our results suggest that recruitment of SPT6L at TSS is indispensable for its spreading along the gene body during transcription. These findings provide new insights into the mechanisms underlying SPT6L recruitment in transcription and shed light on the coordination between transcription initiation and elongation.

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