Putative Transcription Start Site Research Articles

MiRStart 2.0: enhancing miRNA regulatory insights through deep learning-based TSS identification.

MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression by binding to the 3'-untranslated regions of target mRNAs, influencing various biological processes at the post-transcriptional level. Identifying miRNA transcription start sites (TSSs) and transcription factors' (TFs) regulatory roles iscrucial for elucidating miRNA function and transcriptional regulation. miRStart 2.0 integrates over 4500 high-throughput datasets across five data types, utilizing a multi-modal approach to annotate 28828 putative TSSs for 1745 human and 1181 mouse miRNAs, supported by sequencing-based signals. Over 6 million tissue-specific TF-miRNA interactions, integrated from ChIP-seq data, are supplemented by DNase hypersensitivity and UCSC conservation data, with network visualizations. Our deep learning-based model outperforms existing tools in miRNA TSS prediction, achieving the most overlaps with both cell-specific and non-cell-specific validated TSSs. The user-friendly web interface and visualization tools make miRStart 2.0 easily accessible to researchers, enabling efficient identification of miRNA upstream regulatory elements in relation to their TSSs. This updated database provides systems-level insights into gene regulation and disease mechanisms, offering a valuable resource for translational research, facilitating the discovery of novel therapeutic targets and precision medicine strategies. miRStart 2.0 is now accessible at https://awi.cuhk.edu.cn/∼miRStart2.

Protein KIC5 is a novel regulator of artemisinin stress response in the malaria parasite Plasmodium falciparum

Artemisinin combination therapies (ACTs) have led to a significant decrease in Plasmodium falciparum malaria mortality. This progress is now threatened by emerging artemisinin resistance (ART-R) linked originally in SE Asia to polymorphisms in the Kelch propeller protein (K13) and more recently to several other seemingly unrelated genetic mutations. To better understand the parasite response to ART, we are characterizing a P. falciparum mutant with altered sensitivity to ART that was created via piggyBac transposon mutagenesis. The transposon inserted near the putative transcription start site of a gene defined as a “Plasmodium-conserved gene of unknown function,” now functionally linked to K13 as the Kelch13 Interacting Candidate 5 protein (KIC5). Phenotype analysis of the KIC5 mutant during intraerythrocytic asexual development identified transcriptional changes associated with DNA stress response and altered mitochondrial metabolism, linking dysregulation of the KIC5 gene to the parasite’s ability to respond to ART exposure. Through characterization of the KIC5 transcriptome, we hypothesize that this gene may be essential under ART exposure to manage gene expression of the wild-type stress response at early ring stage, thereby providing a better understanding of the parasite’s processes that can alter ART sensitivity.

Nonclimacteric ‘Jen-Ju Bar’ guava ripening behavior is caused by Copia LTR retrotransposon insertion in the promoter region of PgACS1, a System-2 ACC synthase gene

‘Jen-Ju Bar’ (‘JJB’) guava (Psidium guajava L.), a nonclimacteric guava variety featuring delayed peel coloration and pulp softening, exhibits very low ethylene production during the fruit ripening stage and long storability due to the barely detectable activity of 1-aminocyclopropane-1-carboxylate synthase (ACS) and 1-aminocyclopropane-1-carboxylic acid (ACC) content in the pulp. PgACS1, a System-2 ACS gene, has been demonstrated to be a major, if not the only, responsive ACS associated with massive ethylene production during ripening in climacteric guava, such as ‘Li-Tzy Bar’ (‘LTB’). After alignment of the nucleotide sequences of PgACS1 genomic clones between ‘JJB’ and ‘LTB’, the promoter region of ‘JJB’ PgACS1 was found to be interrupted by a retrotransposon. We cloned and characterized the full-length retrotransposon in the promoter region of ‘JJB’ PgACS1. Nucleic acid sequence analysis indicated that the 5487 bp insertion was a Copia long terminal repeat (LTR) retrotransposon, which is oriented in the antisense transcriptional direction of PgACS1 at − 6 upstream of the putative transcription start site (TSS). These results imply that retrotransposon insertion in the promoter region of PgACS1 renders a massive frameshift of the ethylene response element (ERE) cis-element; therefore, the gene was almost silent at the ripening stage. Consequently, ‘JJB’ behaved in a nonclimacteric ripening manner and is feasible for distant marketing. Specific PCR primers targeting the PgACS1 promoter were designed and successfully discriminated the ripening behavior among ten guava cultivars. The primers were suggested for application as molecular markers to assist in early ripening-behavior screening among progenies of a guava breeding project.

Genome-Wide Transcription Start Sites Mapping in Methylorubrum Grown with Dichloromethane and Methanol.

Dichloromethane (DCM, methylene chloride) is a toxic halogenated volatile organic compound massively used for industrial applications, and consequently often detected in the environment as a major pollutant. DCM biotransformation suggests a sustainable decontamination strategy of polluted sites. Among methylotrophic bacteria able to use DCM as a sole source of carbon and energy for growth, Methylorubrum extorquens DM4 is a longstanding reference strain. Here, the primary 5′-ends of transcripts were obtained using a differential RNA-seq (dRNA-seq) approach to provide the first transcription start site (TSS) genome-wide landscape of a methylotroph using DCM or methanol. In total, 7231 putative TSSs were annotated and classified with respect to their localization to coding sequences (CDSs). TSSs on the opposite strand of CDS (antisense TSS) account for 31% of all identified TSSs. One-third of the detected TSSs were located at a distance to the start codon inferior to 250 nt (average of 84 nt) with 7% of leaderless mRNA. Taken together, the global TSS map for bacterial growth using DCM or methanol will facilitate future studies in which transcriptional regulation is crucial, and efficient DCM removal at polluted sites is limited by regulatory processes.

Structural analysis of regulatory stress elements in OsCIPK14 the rice homologue and functional validation in wheat

A major mechanism of stress tolerance in plants is to increase the cytosolic concentration of Ca2+ ion, a secondary messenger that mediates cellular responsiveness to the extracellular environment. The involvement of different types of Ca2+-sensing protein kinases such as CIPK in stress responses has been elucidated in different plant models. In this study, the upstream regulatory sequence of a CIPK homologue from an Egyptian rice cultivar (Oryza sativa cv Giza182) was structurally and functionally characterized and tested for its ability to drive the expression of β- glucuronidase reporter gene (uidA) in wheat. To that end, a 1275-bp DNA fragment, 49 nucleotides upstream of the putative transcription start site (TSS) of the OsCIPK14 coding sequence, referred in this study as URS-CIPK14, was cloned, sequenced and analyzed for the presence of stress-responsiveness cis-acting elements. Subsequently, the URS-CIPK14 was fused to the uidA gene with and without the Act-1 intron, cloned in pAB6 and transformed into wheat mature embryo for transient expression. Our results showed that URS-OsCIPK14 fused with the Act-1 intron was induced by NaCl and ABA, whereas URS-OsCIPK14 drove expression of uidA constitutively in the absence of Act-1 intron. Furthermore, rice wide-genome screening using URS-CIPK14 sequence obtained in this study identified another homologue on chromosome 11. Unlike URS-CIPK14, which is associated with chromosome 12, this homologue located at about 1015 nucleotides upstream from the putative TSS of OsCIPK15 coding sequence. Interestingly, the 5’-UTS in CIPK14 is longer than CIPK15 and can code for a putative short ORF that contains two Casein kinase II phosphorylation motifs (SXXD). The significance of this ORF is not known at this time and needs to be elucidated in future studies. We conclude that data from this work suggest that URS-CIPK14 can be used as a promoter candidate for high expression level under both constitutive and inducible conditions.

The small regulatory RNA Lpr10 regulates the expression of RpoS in Legionella pneumophila.

Legionella pneumophila (Lp) is a waterborne bacterium able to infect human alveolar macrophages, causing Legionnaires' disease. Lp can survive for several months in water, while searching for host cells to grow in, such as ciliates and amoeba. In Lp, the sigma factor RpoS is essential for survival in water. A previous transcriptomic study showed that RpoS positively regulates the small regulatory RNA Lpr10. In the present study, deletion of lpr10 results in an increased survival of Lp in water. Microarray analysis and RT-qPCR revealed that Lpr10 negatively regulates the expression of RpoS in the postexponential phase. Electrophoretic mobility shift assay and in-line probing showed that Lpr10 binds to a region upstream of the previously identified transcription start sites (TSS) of rpoS. A third putative transcription start site was identified by primer extension analysis, upstream of the Lpr10 binding site. In addition, nlpD TSS produces a polycistronic mRNA including the downstream gene rpoS, indicating a fourth TSS for rpoS. Our results suggest that the transcripts from the third and fourth TSS are negatively regulated by the Lpr10 sRNA. Therefore, we propose that Lpr10 is involved in a negative regulatory feedback loop to maintain expression of RpoS to an optimal level.

Identification of a novel long non-coding RNA within RUNX1 intron 5

BackgroundRUNX1 gene, a master regulator of the hematopoietic process, participates in pathological conditions as a partner for several genes in chromosomal translocations. One of the most frequent chromosomal translocations found in acute myeloid leukemia patients is the t(8;21), in which RUNX1 and ETO genes recombine. In RUNX1 gene, the DNA double-strand breaks that originate the t(8;21) are generated in the intron 5, specifically within three regions designated as BCR1, BCR2, and BCR3. To date, what determines that these regions are more susceptible to DNA double-strand breaks is not completely clear. In this report, we characterized RUNX1 intron 5, by analyzing DNase-seq and ChIP-seq data, available in the ENCODE Project server, to evaluate DNaseI hypersensitivity and the presence of the epigenetic mark H3K4me3 in 124 and 51 cell types, respectively.ResultsOur results show that intron 5 exhibits an epigenetic mark distribution similar to known promoter regions. Moreover, using the online tool YAPP and available CAGE data from the ENCODE Project server, we identified several putative transcription start sites within intron 5 in regions BCR2 and BCR3. Finally, available EST data was analyzed, identifying a novel uncharacterized long non-coding RNA, which is expressed in hematopoietic cell lines as shown by RT-PCR. Our data suggests that the core promoter of the novel long non-coding RNA locates within the region BCR3.ConclusionWe identified a novel long non-coding RNA within RUNX1 intron 5, transcribed from a promoter located in the region BCR3, one of the chromosomal breakpoints of RUNX1 gene.

Loss of Both USP10 and p14ARF Protein Expression Is an Independent Prognostic Biomarker for Poor Prognosis in Patients With Epithelial Ovarian Cancer.

The prognostic role of USP10 in epithelial ovarian cancer has been studied in various human cancers. Our aim was to evaluate the clinical and pathological significance of USP10 in epithelial ovarian cancer. Immunohistochemical analyses of the expression of USP10 and p14ARF by using tissue microarrays were performed in 336 ovarian tumours and the data were compared with clinicopathological variables. We examined their level of DNA methylation around the putative transcriptional start site in 5' CpG islands in fresh frozen tissues and ovarian cancer cells. Expression of USP10 and p14ARF was significantly lower in cancer tissues than in normal epithelium. Low USP10 expression and a combined USP10/p14ARF low expression were revealed to be independent prognostic factors. A high degree of methylation in USP10 and p14ARF CpG islands was found by methylation specific PCR analysis in cancer than in normal tissues and cells. Decreased expression of USP10 or combined USP10/p14ARF decreased expression is a strong indicator of poor prognosis in patients with ovarian cancer.

Annotation of Genes on Contig 31 of the Drosophila eugracilis Chromosome 4

Drosophila melanogaster has a small fourth chromosome, the Muller F element (3.5% of the genome), that has very large heterochromatin domains which are rich in HP1. Our goal for this project is to understand the mechanisms of gene expression in this heterochromatic environment. In the Genomics Education Partnership Project, we are using comparative genomics to identify conserved DNA regulatory sequences, by comparing the D. melanogaster Muller F element to those of other fly species that diverged from D. melanogaster ~10 million years ago, aiming to find regions of homology surrounding the transcription start sites. I have annotated the genes on a 40,000 base‐pair piece from the Drosophila eugracilis chromosome four. Sequence comparisons using BLASTX, gene predictors like Gene Scans, and RNA sequence data were used to annotate coding genes in this region. I identified two genes: myo (3 isoforms) and ey (4 isoforms) and annotated protein coding exons and splice sites for each isoform. The myo amino acid sequence is identical for each isoform in D. eugracilis, with 70.3% amino acid identity compared to the D. melanogaster myo protein. The D. eugracilis ey isoforms are also similar to the D. melanogaster ey protein sequences, with a range from 73% to 78% identity to their corresponding D. melanogaster isoform. Putative Transcription Start Sites for each gene were investigated, including a search for known transcription factor binding sites. By pooling results, GEP students are annotating several megabases of DNA, and contributing to an understanding of heterochromatic genes.Support or Funding InformationSupported by NSF IUSE #1431407 and NIH R25GM119157 to Sarah C.R. Elgin (GEP) and NSF HRD#1623340 to MVSThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Zipper plot: visualizing transcriptional activity of genomic regions

BackgroundReconstructing transcript models from RNA-sequencing (RNA-seq) data and establishing these as independent transcriptional units can be a challenging task. Current state-of-the-art tools for long non-coding RNA (lncRNA) annotation are mainly based on evolutionary constraints, which may result in false negatives due to the overall limited conservation of lncRNAs.ResultsTo tackle this problem we have developed the Zipper plot, a novel visualization and analysis method that enables users to simultaneously interrogate thousands of human putative transcription start sites (TSSs) in relation to various features that are indicative for transcriptional activity. These include publicly available CAGE-sequencing, ChIP-sequencing and DNase-sequencing datasets. Our method only requires three tab-separated fields (chromosome, genomic coordinate of the TSS and strand) as input and generates a report that includes a detailed summary table, a Zipper plot and several statistics derived from this plot.ConclusionUsing the Zipper plot, we found evidence of transcription for a set of well-characterized lncRNAs and observed that fewer mono-exonic lncRNAs have CAGE peaks overlapping with their TSSs compared to multi-exonic lncRNAs. Using publicly available RNA-seq data, we found more than one hundred cases where junction reads connected protein-coding gene exons with a downstream mono-exonic lncRNA, revealing the need for a careful evaluation of lncRNA 5′-boundaries. Our method is implemented using the statistical programming language R and is freely available as a webtool.

Abstract A43: TFG-TEC oncogene modulates beta-enolase expression via both promoter activation and epigenetic modification

Abstract Recurrent chromosome translocations are the hallmark of many human cancers. A proportion of human extraskeletal myxoid chondrosarcomas (EMCs) are associated with the characteristic chromosomal translocation t(3;9)(q11-12;q22), which results in the formation of a chimeric protein in which the N-terminal domain of the TRK-fused gene (TFG) is fused to the translocated in extraskeletal chondrosarcoma (TEC; also called CHN, CSMF, MINOR, NOR1, and NR4A3) gene. The oncogenic effect of this translocation may be due to the higher transactivation ability of the TFG-TEC chimeric protein; however, downstream target genes of TFG-TEC have not yet been identified. The results presented here demonstrate that TFG-TEC activates the human beta-enolase promoter. EMSAs, ChIP assays, and luciferase reporter assays revealed that TFG-TEC upregulates beta-enolase transcription by binding to two NGFI-B response element motifs located upstream of the putative transcription start site. In addition, northern blot, quantitative real-time PCR, and western blot analyses showed that overexpression of TFG-TEC up-regulated beta-enolase mRNA and protein expression in cultured cell lines. Finally, ChIP analyses revealed that TFG-TEC controls the activity of the endogenous beta-enolase promoter by promoting histone H3 acetylation. Overall, the results presented here indicate that TFG-TEC triggers a regulatory gene hierarchy implicated in cancer cell metabolism. This finding may aid the development of new therapeutic strategies for the treatment of human EMCs. Citation Format: Ah-young Kim, Bobae Lim, JeeHyun Choi, Jungho Kim. TFG-TEC oncogene modulates beta-enolase expression via both promoter activation and epigenetic modification [abstract]. In: Proceedings of the AACR Special Conference on DNA Repair: Tumor Development and Therapeutic Response; 2016 Nov 2-5; Montreal, QC, Canada. Philadelphia (PA): AACR; Mol Cancer Res 2017;15(4_Suppl):Abstract nr A43.

The mitochondrial genome sequences of the round goby and the sand goby reveal patterns of recent evolution in gobiid fish

BackgroundVertebrate mitochondrial genomes are optimized for fast replication and low cost of RNA expression. Accordingly, they are devoid of introns, are transcribed as polycistrons and contain very little intergenic sequences. Usually, vertebrate mitochondrial genomes measure between 16.5 and 17 kilobases (kb).ResultsDuring genome sequencing projects for two novel vertebrate models, the invasive round goby and the sand goby, we found that the sand goby genome is exceptionally small (16.4 kb), while the mitochondrial genome of the round goby is much larger than expected for a vertebrate. It is 19 kb in size and is thus one of the largest fish and even vertebrate mitochondrial genomes known to date. The expansion is attributable to a sequence insertion downstream of the putative transcriptional start site. This insertion carries traces of repeats from the control region, but is mostly novel. To get more information about this phenomenon, we gathered all available mitochondrial genomes of Gobiidae and of nine gobioid species, performed phylogenetic analyses, analysed gene arrangements, and compared gobiid mitochondrial genome sizes, ecological information and other species characteristics with respect to the mitochondrial phylogeny. This allowed us amongst others to identify a unique arrangement of tRNAs among Ponto-Caspian gobies.ConclusionsOur results indicate that the round goby mitochondrial genome may contain novel features. Since mitochondrial genome organisation is tightly linked to energy metabolism, these features may be linked to its invasion success. Also, the unique tRNA arrangement among Ponto-Caspian gobies may be helpful in studying the evolution of this highly adaptive and invasive species group. Finally, we find that the phylogeny of gobiids can be further refined by the use of longer stretches of linked DNA sequence.

Abstract 957: Regulation of PCGEM1 in castration resistant prostate cancer

Abstract PCGEM1 has been shown to be prostate cancer specific long non-coding RNA (lncRNA). Our previous study indicates that PCGEM1 plays a role in castration resistance through regulation of androgen receptor (AR) splice variants. Although it is known that PCGEM1 is often upregulated in prostate cancer, little is known how PCGEM1 is regulated. In the present study, we show that p54/nrb is a positive regulator for PCGEM1. PCGEM1 is higher in castration resistant CWR22Rv1 than in androgen sensitive LNCaP cells. Moreover, androgen deprivation induces PCGEM1 in LNCaP cells. Histone ChIP assays suggest that the active binding site is within 500 bp upstream of putative transcriptional start site. By using biotin-labelled PCR product and pulldown assays combined with mass spectrometry analysis, we show that p54/nrb interacts with the promoter of PCGEM1. While ectopic expression increases, suppression of p54/nrb by RNAi or knockout (KO) suppresses PCGEM1, supporting a role for p54/nrb in PCGEM1 regulation. Moreover, rescue experiments indicate that re-expression of p54/nrb in KO cells restores the ability to induce PCGEM1. Finally, 3, 3’-Diindolylmethane (DIM), a known chemoprevention agent derived from plants such as broccoli, is capable of suppressing PCGEM1 expression by preventing the interaction of p54/nrb with the PCGEM1 promoter. In particular, DIM reduces tumor growth by suppression of PCGEM1 and promoting apoptosis in the castrated xenograft mouse model. Together, these results demonstrate a novel mechanism of how PCGEM1 and AR splicing are regulated. As a result, PCGEM1 may ultimately contribute to castration resistance. Citation Format: Tsui-Ting Ho, Yin-Yuan Mo. Regulation of PCGEM1 in castration resistant prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 957.

Genome-wide mapping of transcription start sites yields novel insights into the primary transcriptome of Pseudomonas putida.

The environmental bacterium Pseudomonas putida is an organism endowed with a versatile metabolism and stress tolerance traits that are desirable in an efficient production organism. In this work, differential RNA sequencing was used to investigate the primary transcriptome and RNA regulatory elements of P. putida strain KT2440. A total of 7937 putative transcription start sites (TSSs) were identified, where over two-thirds were located either on the opposite strand or internal to annotated genes. For TSSs associated with mRNAs, sequence analysis revealed a clear Shine-Dalgarno sequence but a lack of conserved overrepresented promoter motifs. These TSSs defined approximately 50 leaderless transcripts and an abundance of mRNAs with long leader regions of which 18 contain RNA regulatory elements from the Rfam database. The thiamine pyrophosphate riboswitch upstream of the thiC gene was examined using an in vivo assay with GFP-fusion vectors and shown to function via a translational repression mechanism. Furthermore, 56 novel intergenic small RNAs and 8 putative actuaton transcripts were detected, as well as 8 novel open reading frames (ORFs). This study illustrates how global mapping of TSSs can yield novel insights into the transcriptional features and RNA output of bacterial genomes.

The TFG-TEC oncoprotein induces transcriptional activation of the human β-enolase gene via chromatin modification of the promoter region.

Recurrent chromosome translocations are the hallmark of many human cancers. A proportion of human extraskeletal myxoid chondrosarcomas (EMCs) are associated with the characteristic chromosomal translocation t(3;9)(q11-12;q22), which results in the formation of a chimeric protein in which the N-terminal domain of the TRK-fused gene (TFG) is fused to the translocated in extraskeletal chondrosarcoma (TEC; also called CHN, CSMF, MINOR, NOR1, and NR4A3) gene. The oncogenic effect of this translocation may be due to the higher transactivation ability of the TFG-TEC chimeric protein; however, downstream target genes of TFG-TEC have not yet been identified. The results presented here, demonstrate that TFG-TEC activates the human β-enolase promoter. EMSAs, ChIP assays, and luciferase reporter assays revealed that TFG-TEC upregulates β-enolase transcription by binding to two NGFI-B response element motifs located upstream of the putative transcription start site. In addition, northern blot, quantitative real-time PCR, and Western blot analyses showed that overexpression of TFG-TEC up-regulated β-enolase mRNA and protein expression in cultured cell lines. Finally, ChIP analyses revealed that TFG-TEC controls the activity of the endogenous β-enolase promoter by promoting histone H3 acetylation. Overall, the results presented here indicate that TFG-TEC triggers a regulatory gene hierarchy implicated in cancer cell metabolism. This finding may aid the development of new therapeutic strategies for the treatment of human EMCs. © 2015 Wiley Periodicals, Inc.

NanR, a Transcriptional Regulator That Binds to the Promoters of Genes Involved in Sialic Acid Metabolism in the Anaerobic Pathogen Clostridium perfringens.

Among many other virulence factors, Clostridium perfringens produces three sialidases NanH, NanI and NanJ. NanH lacks a secretion signal peptide and is predicted to be an intracellular enzyme, while NanI and NanJ are secreted. Previously, we had identified part of an operon encoding NanE (epimerase) and NanA (sialic acid lyase) enzymes. Further analysis of the entire operon suggests that it encodes a complete pathway for the transport and metabolism of sialic acid along with a putative transcriptional regulator, NanR. The addition of 30 mM N-acetyl neuraminic acid (Neu5Ac) to a semi-defined medium significantly enhanced the growth yield of strain 13, suggesting that Neu5Ac can be used as a nutrient. C. perfringens strain 13 lacks a nanH gene, but has NanI- and NanJ-encoding genes. Analysis of nanI, nanJ, and nanInanJ mutants constructed by homologous recombination revealed that the expression of the major sialidase, NanI, was induced by the addition of Neu5Ac to the medium, and that in separate experiments, the same was true of a nanI-gusA transcriptional fusion. For the nanI and nanJ genes, primer extension identified three and two putative transcription start sites, respectively. Gel mobility shift assays using purified NanR and DNA from the promoter regions of the nanI and nanE genes showed high affinity, specific binding by NanR. We propose that NanR is a global regulator of sialic acid-associated genes and that it responds, in a positive feedback loop, to the concentration of sialic acid in the cell.

Translational regulation of the expression of the ubiquitin E3 ligase Nedd4–1 by mTORC1-dependent signaling

We found recently that mTORC1 regulates the biosynthesis of the ubiquitin E3 ligase Nedd4–1, but not the close homolog Nedd4–2. This regulatory process plays a key role in promoting neurite growth in neurons of the mammalian central nervous system. The molecular mechanism underlying this rather specific regulation likely involves a pyrimidine-rich sequence stretch near the putative transcriptional start site within the 5′ untranslated region of the Nedd4–1 mRNA, which may play a crucial role in directing the assembly of the protein translation machinery. We postulate that the Nedd4–1 mRNA is a major target of the local translation machinery within neurons that can be translated in a spatially and temporally controlled manner in response to various stimuli. Based on this model, neuronal Nedd4–1 may not only be involved in the regulation of neurite growth but also in axon guidance, spine formation, and synaptic plasticity.

Transgenic reporter mice with promoter region of murine LRAT specifically marks lens and meiosis spermatocytes.

Lecithin:retinol acyltransferase (LRAT) is the major enzyme responsible for retinol esterification in the mammalian body. LRAT exhibits specific activity in the cells with active retinol metabolism where it converts retinols into retinyl esters, which represents the major storage form of retinol. Besides hepatic stellate cells in the liver, LRAT appears to have a key physiologic role in several other tissues. In this study, we generated a transgenic reporter mouse expressing green fluorescence protein (EGFP) under the control of region containing -1166 bps from promoter upstream from the putative transcriptional start site and 262 bps downstream of this start. Transgenic reporter mice exhibited specific expression in eyes and testes. In eyes, expression of EGFP-reporter is found in lens and lens epithelium and fibers from embryo to adulthood. In testes, LRAT-EGFP reporter is expressed both in Sertoli and in spermatocytes marking initiation of spermatogenesis in prepubertal mice. Our data show that the examined LRAT regulatory region is sufficient to achieve strong and selective expression in the eye and testes but not in liver and other organs.

Transcriptome analysis of thermophilic methylotrophic Bacillus methanolicus MGA3 using RNA-sequencing provides detailed insights into its previously uncharted transcriptional landscape.

BackgroundBacillus methanolicus MGA3 is a thermophilic, facultative ribulose monophosphate (RuMP) cycle methylotroph. Together with its ability to produce high yields of amino acids, the relevance of this microorganism as a promising candidate for biotechnological applications is evident. The B. methanolicus MGA3 genome consists of a 3,337,035 nucleotides (nt) circular chromosome, the 19,174 nt plasmid pBM19 and the 68,999 nt plasmid pBM69. 3,218 protein-coding regions were annotated on the chromosome, 22 on pBM19 and 82 on pBM69. In the present study, the RNA-seq approach was used to comprehensively investigate the transcriptome of B. methanolicus MGA3 in order to improve the genome annotation, identify novel transcripts, analyze conserved sequence motifs involved in gene expression and reveal operon structures. For this aim, two different cDNA library preparation methods were applied: one which allows characterization of the whole transcriptome and another which includes enrichment of primary transcript 5′-ends.ResultsAnalysis of the primary transcriptome data enabled the detection of 2,167 putative transcription start sites (TSSs) which were categorized into 1,642 TSSs located in the upstream region (5′-UTR) of known protein-coding genes and 525 TSSs of novel antisense, intragenic, or intergenic transcripts. Firstly, 14 wrongly annotated translation start sites (TLSs) were corrected based on primary transcriptome data. Further investigation of the identified 5′-UTRs resulted in the detailed characterization of their length distribution and the detection of 75 hitherto unknown cis-regulatory RNA elements. Moreover, the exact TSSs positions were utilized to define conserved sequence motifs for translation start sites, ribosome binding sites and promoters in B. methanolicus MGA3. Based on the whole transcriptome data set, novel transcripts, operon structures and mRNA abundances were determined. The analysis of the operon structures revealed that almost half of the genes are transcribed monocistronically (940), whereas 1,164 genes are organized in 381 operons. Several of the genes related to methylotrophy had highly abundant transcripts.ConclusionThe extensive insights into the transcriptional landscape of B. methanolicus MGA3, gained in this study, represent a valuable foundation for further comparative quantitative transcriptome analyses and possibly also for the development of molecular biology tools which at present are very limited for this organism.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1239-4) contains supplementary material, which is available to authorized users.

Improving the genome annotation of the acarbose producer Actinoplanes sp. SE50/110 by sequencing enriched 5′-ends of primary transcripts

Actinoplanes sp. SE50/110 is the producer of the alpha-glucosidase inhibitor acarbose, which is an economically relevant and potent drug in the treatment of type-2 diabetes mellitus. In this study, we present the detection of transcription start sites on this genome by sequencing enriched 5′-ends of primary transcripts. Altogether, 1427 putative transcription start sites were initially identified. With help of the annotated genome sequence, 661 transcription start sites were found to belong to the leader region of protein-coding genes with the surprising result that roughly 20% of these genes rank among the class of leaderless transcripts. Next, conserved promoter motifs were identified for protein-coding genes with and without leader sequences. The mapped transcription start sites were finally used to improve the annotation of the Actinoplanes sp. SE50/110 genome sequence. Concerning protein-coding genes, 41 translation start sites were corrected and 9 novel protein-coding genes could be identified. In addition to this, 122 previously undetermined non-coding RNA (ncRNA) genes of Actinoplanes sp. SE50/110 were defined. Focusing on antisense transcription start sites located within coding genes or their leader sequences, it was discovered that 96 of those ncRNA genes belong to the class of antisense RNA (asRNA) genes. The remaining 26 ncRNA genes were found outside of known protein-coding genes. Four chosen examples of prominent ncRNA genes, namely the transfer messenger RNA gene ssrA, the ribonuclease P class A RNA gene rnpB, the cobalamin riboswitch RNA gene cobRS, and the selenocysteine-specific tRNA gene selC, are presented in more detail. This study demonstrates that sequencing of enriched 5′-ends of primary transcripts and the identification of transcription start sites are valuable tools for advanced genome annotation of Actinoplanes sp. SE50/110 and most probably also for other bacteria.