1
|
Sahrhage M, Paul NB, Beißbarth T, Haubrock M. The importance of DNA sequence for nucleosome positioning in transcriptional regulation. Life Sci Alliance 2024; 7:e202302380. [PMID: 38830772 PMCID: PMC11147951 DOI: 10.26508/lsa.202302380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 05/15/2024] [Accepted: 05/16/2024] [Indexed: 06/05/2024] Open
Abstract
Nucleosome positioning is a key factor for transcriptional regulation. Nucleosomes regulate the dynamic accessibility of chromatin and interact with the transcription machinery at every stage. Influences to steer nucleosome positioning are diverse, and the according importance of the DNA sequence in contrast to active chromatin remodeling has been the subject of long discussion. In this study, we evaluate the functional role of DNA sequence for all major elements along the process of transcription. We developed a random forest classifier based on local DNA structure that assesses the sequence-intrinsic support for nucleosome positioning. On this basis, we created a simple data resource that we applied genome-wide to the human genome. In our comprehensive analysis, we found a special role of DNA in mediating the competition of nucleosomes with cis-regulatory elements, in enabling steady transcription, for positioning of stable nucleosomes in exons, and for repelling nucleosomes during transcription termination. In contrast, we relate these findings to concurrent processes that generate strongly positioned nucleosomes in vivo that are not mediated by sequence, such as energy-dependent remodeling of chromatin.
Collapse
Affiliation(s)
- Malte Sahrhage
- Department of Medical Bioinformatics, University Medical Center, Göttingen, Germany
| | - Niels Benjamin Paul
- Department of Medical Bioinformatics, University Medical Center, Göttingen, Germany
- Department of Cardiology and Pneumology, University Medical Center, Göttingen, Germany
| | - Tim Beißbarth
- Department of Medical Bioinformatics, University Medical Center, Göttingen, Germany
| | - Martin Haubrock
- Department of Medical Bioinformatics, University Medical Center, Göttingen, Germany
| |
Collapse
|
2
|
Aqeel SM, Abdulqader AA, Du G, Liu S. Integrated strategies for efficient production of Streptomyces mobaraensis transglutaminase in Komagataella phaffii. Int J Biol Macromol 2024; 273:133113. [PMID: 38885870 DOI: 10.1016/j.ijbiomac.2024.133113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/21/2024] [Accepted: 06/10/2024] [Indexed: 06/20/2024]
Abstract
Transglutaminase (TGase) from Streptomyces mobaraensis commonly used to improve protein-based foods due to its unique enzymatic reactions, which imply considerable attention in its production. Recently, TGase exhibit broad market potential in non-food industries. However, achieving efficient synthesis of TGase remains a significant challenge. Herein, we achieved a substantial amount of a fully functional and kinetically stable TGase produced by Komagataella phaffii (Pichia pastoris) using multiple strategies including Geneticin (G418) screening, combinatorial mutations, promoter optimization, and co-expression. The active TGase expression reached a maximum of 10.1 U mL-1 in shake flask upon 96 h of induction, which was 3.8-fold of the wild type. Also, the engineered strain exhibited a 6.4-fold increase in half-life and a 2-fold increase in specific activity, reaching 172.67 min at 60 °C (t1/2(60 °C)) and 65.3 U mg-1, respectively. Moreover, the high-cell density cultivation in 5-L fermenter was also applied to test the productivity at large scale. Following optimization at a fermenter, the secretory yield of TGase reached 47.96 U mL-1 in the culture supernatant. Given the complexity inherent in protein expression and secretion, our research is of great significance and offers a comprehensive guide for improving the production of a wide range of heterologous proteins.
Collapse
Affiliation(s)
- Sahibzada Muhammad Aqeel
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China
| | - Al-Adeeb Abdulqader
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China
| | - Guocheng Du
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China; The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
| | - Song Liu
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
| |
Collapse
|
3
|
Segura J, Díaz-Ingelmo O, Martínez-García B, Ayats-Fraile A, Nikolaou C, Roca J. Nucleosomal DNA has topological memory. Nat Commun 2024; 15:4526. [PMID: 38806488 PMCID: PMC11133463 DOI: 10.1038/s41467-024-49023-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 05/21/2024] [Indexed: 05/30/2024] Open
Abstract
One elusive aspect of the chromosome architecture is how it constrains the DNA topology. Nucleosomes stabilise negative DNA supercoils by restraining a DNA linking number difference (∆Lk) of about -1.26. However, whether this capacity is uniform across the genome is unknown. Here, we calculate the ∆Lk restrained by over 4000 nucleosomes in yeast cells. To achieve this, we insert each nucleosome in a circular minichromosome and perform Topo-seq, a high-throughput procedure to inspect the topology of circular DNA libraries in one gel electrophoresis. We show that nucleosomes inherently restrain distinct ∆Lk values depending on their genomic origin. Nucleosome DNA topologies differ at gene bodies (∆Lk = -1.29), intergenic regions (∆Lk = -1.23), rDNA genes (∆Lk = -1.24) and telomeric regions (∆Lk = -1.07). Nucleosomes near the transcription start and termination sites also exhibit singular DNA topologies. Our findings demonstrate that nucleosome DNA topology is imprinted by its native chromatin context and persists when the nucleosome is relocated.
Collapse
Affiliation(s)
- Joana Segura
- DNA Topology Lab, Molecular Biology Institute of Barcelona (IBMB-CSIC), Barcelona, Spain
- Centro de Biología Molecular Severo Ochoa (CSIC/UAM), Madrid, Spain
| | - Ofelia Díaz-Ingelmo
- DNA Topology Lab, Molecular Biology Institute of Barcelona (IBMB-CSIC), Barcelona, Spain
| | - Belén Martínez-García
- DNA Topology Lab, Molecular Biology Institute of Barcelona (IBMB-CSIC), Barcelona, Spain
| | - Alba Ayats-Fraile
- DNA Topology Lab, Molecular Biology Institute of Barcelona (IBMB-CSIC), Barcelona, Spain
| | | | - Joaquim Roca
- DNA Topology Lab, Molecular Biology Institute of Barcelona (IBMB-CSIC), Barcelona, Spain.
| |
Collapse
|
4
|
Roldán-Piñero C, Luengo-Márquez J, Assenza S, Pérez R. Systematic Comparison of Atomistic Force Fields for the Mechanical Properties of Double-Stranded DNA. J Chem Theory Comput 2024; 20:2261-2272. [PMID: 38411091 PMCID: PMC10938644 DOI: 10.1021/acs.jctc.3c01089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 02/14/2024] [Accepted: 02/14/2024] [Indexed: 02/28/2024]
Abstract
The response of double-stranded DNA to external mechanical stress plays a central role in its interactions with the protein machinery in the cell. Modern atomistic force fields have been shown to provide highly accurate predictions for the fine structural features of the duplex. In contrast, and despite their pivotal function, less attention has been devoted to the accuracy of the prediction of the elastic parameters. Several reports have addressed the flexibility of double-stranded DNA via all-atom molecular dynamics, yet the collected information is insufficient to have a clear understanding of the relative performance of the various force fields. In this work, we fill this gap by performing a systematic study in which several systems, characterized by different sequence contexts, are simulated with the most popular force fields within the AMBER family, bcs1 and OL15, as well as with CHARMM36. Analysis of our results, together with their comparison with previous work focused on bsc0, allows us to unveil the differences in the predicted rigidity between the newest force fields and suggests a roadmap to test their performance against experiments. In the case of the stretch modulus, we reconcile these differences, showing that a single mapping between sequence-dependent conformation and elasticity via the crookedness parameter captures simultaneously the results of all force fields, supporting the key role of crookedness in the mechanical response of double-stranded DNA.
Collapse
Affiliation(s)
- Carlos Roldán-Piñero
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Juan Luengo-Márquez
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Instituto
Nicolás Cabrera, Universidad Autónoma
de Madrid, E-28049 Madrid, Spain
| | - Salvatore Assenza
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Instituto
Nicolás Cabrera, Universidad Autónoma
de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad
Autónoma de Madrid, E-28049 Madrid, Spain
| | - Rubén Pérez
- Departamento
de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain
- Condensed
Matter Physics Center (IFIMAC), Universidad
Autónoma de Madrid, E-28049 Madrid, Spain
| |
Collapse
|
5
|
Marie C, Scherman D. Antibiotic-Free Gene Vectors: A 25-Year Journey to Clinical Trials. Genes (Basel) 2024; 15:261. [PMID: 38540320 PMCID: PMC10970329 DOI: 10.3390/genes15030261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/07/2024] [Accepted: 02/15/2024] [Indexed: 06/15/2024] Open
Abstract
Until very recently, the major use, for gene therapy, specifically of linear or circular DNA, such as plasmids, was as ancillary products for viral vectors' production or as a genetic template for mRNA production. Thanks to targeted and more efficient physical or chemical delivery techniques and to the refinement of their structure, non-viral plasmid DNA are now under intensive consideration as pharmaceutical drugs. Plasmids traditionally carry an antibiotic resistance gene for providing the selection pressure necessary for maintenance in a bacterial host. Nearly a dozen different antibiotic-free gene vectors have now been developed and are currently assessed in preclinical assays and phase I/II clinical trials. Their reduced size leads to increased transfection efficiency and prolonged transgene expression. In addition, associating non-viral gene vectors and DNA transposons, which mediate transgene integration into the host genome, circumvents plasmid dilution in dividing eukaryotic cells which generate a loss of the therapeutic gene. Combining these novel molecular tools allowed a significantly higher yield of genetically engineered T and Natural Killer cells for adoptive immunotherapies due to a reduced cytotoxicity and increased transposition rate. This review describes the main progresses accomplished for safer, more efficient and cost-effective gene and cell therapies using non-viral approaches and antibiotic-free gene vectors.
Collapse
Affiliation(s)
- Corinne Marie
- Université Paris Cité, CNRS, Inserm, UTCBS, 75006 Paris, France;
- Chimie ParisTech, Université PSL, 75005 Paris, France
| | - Daniel Scherman
- Université Paris Cité, CNRS, Inserm, UTCBS, 75006 Paris, France;
- Fondation Maladies Rares, 75014 Paris, France
| |
Collapse
|
6
|
Zhu Y, Vvedenskaya IO, Sze SH, Nickels BE, Kaplan CD. Quantitative analysis of transcription start site selection reveals control by DNA sequence, RNA polymerase II activity and NTP levels. Nat Struct Mol Biol 2024; 31:190-202. [PMID: 38177677 PMCID: PMC10928753 DOI: 10.1038/s41594-023-01171-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 11/03/2023] [Indexed: 01/06/2024]
Abstract
Transcription start site (TSS) selection is a key step in gene expression and occurs at many promoter positions over a wide range of efficiencies. Here we develop a massively parallel reporter assay to quantitatively dissect contributions of promoter sequence, nucleoside triphosphate substrate levels and RNA polymerase II (Pol II) activity to TSS selection by 'promoter scanning' in Saccharomyces cerevisiae (Pol II MAssively Systematic Transcript End Readout, 'Pol II MASTER'). Using Pol II MASTER, we measure the efficiency of Pol II initiation at 1,000,000 individual TSS sequences in a defined promoter context. Pol II MASTER confirms proposed critical qualities of S. cerevisiae TSS -8, -1 and +1 positions, quantitatively, in a controlled promoter context. Pol II MASTER extends quantitative analysis to surrounding sequences and determines that they tune initiation over a wide range of efficiencies. These results enabled the development of a predictive model for initiation efficiency based on sequence. We show that genetic perturbation of Pol II catalytic activity alters initiation efficiency mostly independently of TSS sequence, but selectively modulates preference for the initiating nucleotide. Intriguingly, we find that Pol II initiation efficiency is directly sensitive to guanosine-5'-triphosphate levels at the first five transcript positions and to cytosine-5'-triphosphate and uridine-5'-triphosphate levels at the second position genome wide. These results suggest individual nucleoside triphosphate levels can have transcript-specific effects on initiation, representing a cryptic layer of potential regulation at the level of Pol II biochemical properties. The results establish Pol II MASTER as a method for quantitative dissection of transcription initiation in eukaryotes.
Collapse
Affiliation(s)
- Yunye Zhu
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Irina O Vvedenskaya
- Department of Genetics and Waksman Institute, Rutgers University, Piscataway, NJ, USA
| | - Sing-Hoi Sze
- Department of Biochemistry and Biophysics, Texas A&M University, College Station, TX, USA
- Department of Computer Science and Engineering, Texas A&M University, College Station, TX, USA
| | - Bryce E Nickels
- Department of Genetics and Waksman Institute, Rutgers University, Piscataway, NJ, USA
| | - Craig D Kaplan
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
7
|
Arjmand S. Promoters in Pichia pastoris: A Toolbox for Fine-Tuned Gene Expression. Methods Mol Biol 2024; 2844:159-178. [PMID: 39068339 DOI: 10.1007/978-1-0716-4063-0_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
This chapter reviews the different promoters used to control gene expression in the yeast Pichia pastoris, mainly for recombinant protein production. It covers natural inducible, derepressed, and constitutive promoters, as well as engineered synthetic/hybrid promoters, orthologous promoters from related yeasts, and emerging bidirectional promoters. Key examples, characteristics, and regulatory mechanisms are discussed for each promoter class. Recent efforts in promoter engineering through rational design, mutagenesis, and computational approaches are also highlighted. Looking ahead, we anticipate further developments that will enhance promoter design for Pichia pastoris. Overall, this comprehensive overview underscores the importance of promoter choice and engineering for fully harnessing Pichia pastoris biotechnological potential.
Collapse
Affiliation(s)
- Sareh Arjmand
- Protein Research Center, Shahid Beheshti University, Tehran, Iran.
| |
Collapse
|
8
|
Chen B, MacAlpine HK, Hartemink AJ, MacAlpine DM. Spatiotemporal kinetics of CAF-1-dependent chromatin maturation ensures transcription fidelity during S-phase. Genome Res 2023; 33:2108-2118. [PMID: 38081658 PMCID: PMC10760526 DOI: 10.1101/gr.278273.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 11/13/2023] [Indexed: 12/26/2023]
Abstract
Proper maintenance of epigenetic information after replication is dependent on the rapid assembly and maturation of chromatin. Chromatin Assembly Complex 1 (CAF-1) is a conserved histone chaperone that deposits (H3-H4)2 tetramers as part of the replication-dependent chromatin assembly process. Loss of CAF-1 leads to a delay in chromatin maturation, albeit with minimal impact on steady-state chromatin structure. However, the mechanisms by which CAF-1 mediates the deposition of (H3-H4)2 tetramers and the phenotypic consequences of CAF-1-associated assembly defects are not well understood. We used nascent chromatin occupancy profiling to track the spatiotemporal kinetics of chromatin maturation in both wild-type (WT) and CAF-1 mutant yeast cells. Our results show that loss of CAF-1 leads to a heterogeneous rate of nucleosome assembly, with some nucleosomes maturing at near WT kinetics and others showing significantly slower maturation kinetics. The slow-to-mature nucleosomes are enriched in intergenic and poorly transcribed regions, suggesting that transcription-dependent assembly mechanisms can reset the slow-to-mature nucleosomes following replication. Nucleosomes with slow maturation kinetics are also associated with poly(dA:dT) sequences, which implies that CAF-1 deposits histones in a manner that counteracts resistance from the inflexible DNA sequence, promoting the formation of histone octamers as well as ordered nucleosome arrays. In addition, we show that the delay in chromatin maturation is accompanied by a transient and S-phase-specific loss of gene silencing and transcriptional regulation, revealing that the DNA replication program can directly shape the chromatin landscape and modulate gene expression through the process of chromatin maturation.
Collapse
Affiliation(s)
- Boning Chen
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Heather K MacAlpine
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | | | - David M MacAlpine
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA;
| |
Collapse
|
9
|
Back G, Walther D. Predictions of DNA mechanical properties at a genomic scale reveal potentially new functional roles of DNA flexibility. NAR Genom Bioinform 2023; 5:lqad097. [PMID: 37954573 PMCID: PMC10632188 DOI: 10.1093/nargab/lqad097] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 09/28/2023] [Accepted: 10/25/2023] [Indexed: 11/14/2023] Open
Abstract
Mechanical properties of DNA have been implied to influence many of its biological functions. Recently, a new high-throughput method, called loop-seq, which allows measuring the intrinsic bendability of DNA fragments, has been developed. Using loop-seq data, we created a deep learning model to explore the biological significance of local DNA flexibility in a range of different species from different kingdoms. Consistently, we observed a characteristic and largely dinucleotide-composition-driven change of local flexibility near transcription start sites. In the presence of a TATA-box, a pronounced peak of high flexibility can be observed. Furthermore, depending on the transcription factor investigated, flanking-sequence-dependent DNA flexibility was identified as a potential factor influencing DNA binding. Compared to randomized genomic sequences, depending on species and taxa, actual genomic sequences were observed both with increased and lowered flexibility. Furthermore, in Arabidopsis thaliana, mutation rates, both de novo and fixed, were found to be associated with relatively rigid sequence regions. Our study presents a range of significant correlations between characteristic DNA mechanical properties and genomic features, the significance of which with regard to detailed molecular relevance awaits further theoretical and experimental exploration.
Collapse
Affiliation(s)
- Georg Back
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam-Golm 14476, Germany
| | - Dirk Walther
- Max Planck Institute of Molecular Plant Physiology, Am Mühlenberg 1, Potsdam-Golm 14476, Germany
| |
Collapse
|
10
|
Amigo R, Raiqueo F, Tarifeño E, Farkas C, Gutiérrez JL. Poly(dA:dT) Tracts Differentially Modulate Nucleosome Remodeling Activity of RSC and ISW1a Complexes, Exerting Tract Orientation-Dependent and -Independent Effects. Int J Mol Sci 2023; 24:15245. [PMID: 37894925 PMCID: PMC10607297 DOI: 10.3390/ijms242015245] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/27/2023] [Accepted: 10/05/2023] [Indexed: 10/29/2023] Open
Abstract
The establishment and maintenance of nucleosome-free regions (NFRs) are prominent processes within chromatin dynamics. Transcription factors, ATP-dependent chromatin remodeling complexes (CRCs) and DNA sequences are the main factors involved. In Saccharomyces cerevisiae, CRCs such as RSC contribute to chromatin opening at NFRs, while other complexes, including ISW1a, contribute to NFR shrinking. Regarding DNA sequences, growing evidence points to poly(dA:dT) tracts as playing a direct role in active processes involved in nucleosome positioning dynamics. Intriguingly, poly(dA:dT)-tract-containing NFRs span asymmetrically relative to the location of the tract by a currently unknown mechanism. In order to obtain insight into the role of poly(dA:dT) tracts in nucleosome remodeling, we performed a systematic analysis of their influence on the activity of ISW1a and RSC complexes. Our results show that poly(dA:dT) tracts differentially affect the activity of these CRCs. Moreover, we found differences between the effects exerted by the two alternative tract orientations. Remarkably, tract-containing linker DNA is taken as exit DNA for nucleosome sliding catalyzed by RSC. Our findings show that defined DNA sequences, when present in linker DNA, can dictate in which direction a remodeling complex has to slide nucleosomes and shed light into the mechanisms underlying asymmetrical chromatin opening around poly(dA:dT) tracts.
Collapse
Affiliation(s)
- Roberto Amigo
- Laboratory of Transcriptional Regulation, Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción, Concepción 4070043, Chile; (R.A.); (F.R.); (E.T.)
| | - Fernanda Raiqueo
- Laboratory of Transcriptional Regulation, Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción, Concepción 4070043, Chile; (R.A.); (F.R.); (E.T.)
| | - Estefanía Tarifeño
- Laboratory of Transcriptional Regulation, Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción, Concepción 4070043, Chile; (R.A.); (F.R.); (E.T.)
| | - Carlos Farkas
- Biomedical Sciences Research Laboratory, Department of Basic Sciences and Morphology, Faculty of Medicine, Universidad Católica de la Santísima Concepción, Concepción 4090541, Chile;
| | - José L. Gutiérrez
- Laboratory of Transcriptional Regulation, Department of Biochemistry and Molecular Biology, Faculty of Biological Sciences, University of Concepción, Concepción 4070043, Chile; (R.A.); (F.R.); (E.T.)
| |
Collapse
|
11
|
Poulet A, Kratkiewicz AJ, Li D, van Wolfswinkel JC. Chromatin analysis of adult pluripotent stem cells reveals a unique stemness maintenance strategy. SCIENCE ADVANCES 2023; 9:eadh4887. [PMID: 37801496 PMCID: PMC10558129 DOI: 10.1126/sciadv.adh4887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 09/05/2023] [Indexed: 10/08/2023]
Abstract
Many highly regenerative organisms maintain adult pluripotent stem cells throughout their life, but how the long-term maintenance of pluripotency is accomplished is unclear. To decipher the regulatory logic of adult pluripotent stem cells, we analyzed the chromatin organization of stem cell genes in the planarian Schmidtea mediterranea. We identify a special chromatin state of stem cell genes, which is distinct from that of tissue-specific genes and resembles constitutive genes. Where tissue-specific promoters have detectable transcription factor binding sites, the promoters of stem cell-specific genes instead have sequence features that broadly decrease nucleosome binding affinity. This genic organization makes pluripotency-related gene expression the default state in these cells, which is maintained by the activity of chromatin remodelers ISWI and SNF2 in the stem cells.
Collapse
Affiliation(s)
- Axel Poulet
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Arcadia J. Kratkiewicz
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Danyan Li
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
| | - Josien C. van Wolfswinkel
- Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA
- Yale Stem Cell Center, Yale School of Medicine, New Haven, CT 06511, USA
- Yale Center for RNA Science and Medicine, Yale School of Medicine, New Haven, CT 06511, USA
| |
Collapse
|
12
|
Chen YT, Yang H, Chu JW. Mechanical codes of chemical-scale specificity in DNA motifs. Chem Sci 2023; 14:10155-10166. [PMID: 37772098 PMCID: PMC10529945 DOI: 10.1039/d3sc01671d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 08/28/2023] [Indexed: 09/30/2023] Open
Abstract
In gene transcription, certain sequences of double-stranded (ds)DNA play a vital role in nucleosome positioning and expression initiation. That dsDNA is deformed to various extents in these processes leads us to ask: Could the genomic DNA also have sequence specificity in its chemical-scale mechanical properties? We approach this question using statistical machine learning to determine the rigidity between DNA chemical moieties. What emerges for the polyA, polyG, TpA, and CpG sequences studied here is a unique trigram that contains the quantitative mechanical strengths between bases and along the backbone. In a way, such a sequence-dependent trigram could be viewed as a DNA mechanical code. Interestingly, we discover a compensatory competition between the axial base-stacking interaction and the transverse base-pairing interaction, and such a reciprocal relationship constitutes the most discriminating feature of the mechanical code. Our results also provide chemical-scale understanding for experimental observables. For example, the long polyA persistence length is shown to have strong base stacking while its complement (polyAc) exhibits high backbone rigidity. The mechanical code concept enables a direct reading of the physical interactions encoded in the sequence which, with further development, is expected to shed new light on DNA allostery and DNA-binding drugs.
Collapse
Affiliation(s)
- Yi-Tsao Chen
- Institute of Bioinformatics and Systems Biology, National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan Republic of China
| | - Haw Yang
- Department of Chemistry, Princeton University Princeton NJ 08544 USA
| | - Jhih-Wei Chu
- Institute of Bioinformatics and Systems Biology, National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan Republic of China
- Department of Biological Science and Technology, Institute of Molecular Medicine and Bioengineering, Center for Intelligent Drug Systems and Smart Bio-devices (IDS2B), National Yang Ming Chiao Tung University Hsinchu 30010 Taiwan Republic of China
| |
Collapse
|
13
|
Poulsgaard GA, Sørensen SG, Juul RI, Nielsen MM, Pedersen JS. Sequence dependencies and mutation rates of localized mutational processes in cancer. Genome Med 2023; 15:63. [PMID: 37592287 PMCID: PMC10436389 DOI: 10.1186/s13073-023-01217-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 08/02/2023] [Indexed: 08/19/2023] Open
Abstract
BACKGROUND Cancer mutations accumulate through replication errors and DNA damage coupled with incomplete repair. Individual mutational processes often show nucleotide sequence and functional region preferences. As a result, some sequence contexts mutate at much higher rates than others, with additional variation found between functional regions. Mutational hotspots, with recurrent mutations across cancer samples, represent genomic positions with elevated mutation rates, often caused by highly localized mutational processes. METHODS We count the 11-mer genomic sequences across the genome, and using the PCAWG set of 2583 pan-cancer whole genomes, we associate 11-mers with mutational signatures, hotspots of single nucleotide variants, and specific genomic regions. We evaluate the mutation rates of individual and combined sets of 11-mers and derive mutational sequence motifs. RESULTS We show that hotspots generally identify highly mutable sequence contexts. Using these, we show that some mutational signatures are enriched in hotspot sequence contexts, corresponding to well-defined sequence preferences for the underlying localized mutational processes. This includes signature 17b (of unknown etiology) and signatures 62 (POLE deficiency), 7a (UV), and 72 (linked to lymphomas). In some cases, the mutation rate and sequence preference increase further when focusing on certain genomic regions, such as signature 62 in transcribed regions, where the mutation rate is increased up to 9-folds over cancer type and mutational signature average. CONCLUSIONS We summarize our findings in a catalog of localized mutational processes, their sequence preferences, and their estimated mutation rates.
Collapse
Affiliation(s)
- Gustav Alexander Poulsgaard
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 82, 8200, Aarhus N, Denmark
- Department of Molecular Medicine (MOMA), Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus N, Denmark
| | - Simon Grund Sørensen
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 82, 8200, Aarhus N, Denmark
- Department of Molecular Medicine (MOMA), Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus N, Denmark
| | - Randi Istrup Juul
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 82, 8200, Aarhus N, Denmark
- Department of Molecular Medicine (MOMA), Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus N, Denmark
| | - Morten Muhlig Nielsen
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 82, 8200, Aarhus N, Denmark
- Department of Molecular Medicine (MOMA), Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus N, Denmark
| | - Jakob Skou Pedersen
- Department of Clinical Medicine, Aarhus University, Palle Juul-Jensens Boulevard 82, 8200, Aarhus N, Denmark.
- Department of Molecular Medicine (MOMA), Aarhus University Hospital, Palle Juul-Jensens Boulevard 99, 8200, Aarhus N, Denmark.
- Bioinformatics Research Centre (BiRC), Aarhus University, University City 81, Building 1872, 3Rd Floor, 8000, Aarhus C, Denmark.
| |
Collapse
|
14
|
Robainas-Del-Pino Y, Viader-Salvadó JM, Herrera-Estala AL, Guerrero-Olazarán M. Functional characterization of the Komagataella phaffii 1033 gene promoter and transcriptional terminator. World J Microbiol Biotechnol 2023; 39:246. [PMID: 37420160 DOI: 10.1007/s11274-023-03682-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 06/16/2023] [Indexed: 07/09/2023]
Abstract
The methylotrophic yeast Komagataella phaffii (syn. Pichia pastoris) is a widely used host for extracellularly producing heterologous proteins via an expression cassette integrated into the yeast genome. A strong promoter in the expression cassette is not always the most favorable choice for heterologous protein production, especially if the correct folding of the protein and/or post-translational processing is the limiting step. The transcriptional terminator is another regulatory element in the expression cassette that can modify the expression levels of the heterologous gene. In this work, we identified and functionally characterized the promoter (P1033) and transcriptional terminator (T1033) of a constitutive gene (i.e., the 1033 gene) with a weak non-methanol-dependent transcriptional activity. We constructed two K. phaffii strains with two combinations of the regulatory DNA elements from the 1033 and AOX1 genes (i.e., P1033-TAOX1 and P1033-T1033 pairs) and evaluated the impact of the regulatory element combinations on the transcript levels of the heterologous gene and endogenous 1033 and GAPDH genes in cells grown in glucose or glycerol, and on the extracellular product/biomass yield. The results indicate that the P1033 has a 2-3% transcriptional activity of the GAP promoter and it is tunable by cell growth and the carbon source. The combinations of the regulatory elements rendered different transcriptional activity of the heterologous and endogenous genes that were dependent on the carbon source. The promoter-terminator pair and the carbon source affected the heterologous gene translation and/or protein secretion pathway. Moreover, low heterologous gene-transcript levels along with glycerol cultures increased translation and/or protein secretion.
Collapse
Affiliation(s)
- Yanelis Robainas-Del-Pino
- Facultad de Ciencias Biológicas, Instituto de Biotecnología, Universidad Autónoma de Nuevo León UANL, Av. Universidad S/N Col. Ciudad Universitaria, 66455, San Nicolás de los Garza, Nuevo León, Mexico
| | - José María Viader-Salvadó
- Facultad de Ciencias Biológicas, Instituto de Biotecnología, Universidad Autónoma de Nuevo León UANL, Av. Universidad S/N Col. Ciudad Universitaria, 66455, San Nicolás de los Garza, Nuevo León, Mexico.
| | - Ana Lucía Herrera-Estala
- Facultad de Ciencias Biológicas, Instituto de Biotecnología, Universidad Autónoma de Nuevo León UANL, Av. Universidad S/N Col. Ciudad Universitaria, 66455, San Nicolás de los Garza, Nuevo León, Mexico
| | - Martha Guerrero-Olazarán
- Facultad de Ciencias Biológicas, Instituto de Biotecnología, Universidad Autónoma de Nuevo León UANL, Av. Universidad S/N Col. Ciudad Universitaria, 66455, San Nicolás de los Garza, Nuevo León, Mexico.
| |
Collapse
|
15
|
Gvozdenov Z, Barcutean Z, Struhl K. Functional analysis of a random-sequence chromosome reveals a high level and the molecular nature of transcriptional noise in yeast cells. Mol Cell 2023; 83:1786-1797.e5. [PMID: 37137302 PMCID: PMC10247422 DOI: 10.1016/j.molcel.2023.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 02/18/2023] [Accepted: 04/10/2023] [Indexed: 05/05/2023]
Abstract
We measure transcriptional noise in yeast by analyzing chromatin structure and transcription of an 18-kb region of DNA whose sequence was randomly generated. Nucleosomes fully occupy random-sequence DNA, but nucleosome-depleted regions (NDRs) are much less frequent, and there are fewer well-positioned nucleosomes and shorter nucleosome arrays. Steady-state levels of random-sequence RNAs are comparable to yeast mRNAs, although transcription and decay rates are higher. Transcriptional initiation from random-sequence DNA occurs at numerous sites, indicating very low intrinsic specificity of the RNA Pol II machinery. In contrast, poly(A) profiles of random-sequence RNAs are roughly comparable to those of yeast mRNAs, suggesting limited evolutionary restraints on poly(A) site choice. Random-sequence RNAs show higher cell-to-cell variability than yeast mRNAs, suggesting that functional elements limit variability. These observations indicate that transcriptional noise occurs at high levels in yeast, and they provide insight into how chromatin and transcription patterns arise from the evolved yeast genome.
Collapse
Affiliation(s)
- Zlata Gvozdenov
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Zeno Barcutean
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | - Kevin Struhl
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
| |
Collapse
|
16
|
Chen B, MacAlpine HK, Hartemink AJ, MacAlpine DM. Spatiotemporal kinetics of CAF-1-dependent chromatin maturation ensures transcription fidelity during S-phase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.25.541209. [PMID: 37292814 PMCID: PMC10245875 DOI: 10.1101/2023.05.25.541209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Proper maintenance of epigenetic information after replication is dependent on the rapid assembly and maturation of chromatin. Chromatin Assembly Complex 1 (CAF-1) is a conserved histone chaperone that deposits (H3-H4)2 tetramers as part of the replication-dependent chromatin assembly process. Loss of CAF-1 leads to a delay in chromatin maturation, albeit with minimal impact on steady-state chromatin structure. However, the mechanisms by which CAF-1 mediates the deposition of (H3-H4)2 tetramers and the phenotypic consequences of CAF-1-associated assembly defects are not well understood. We used nascent chromatin occupancy profiling to track the spatiotemporal kinetics of chromatin maturation in both wild-type (WT) and CAF-1 mutant yeast cells. Our results show that loss of CAF-1 leads to a heterogeneous rate of nucleosome assembly, with some nucleosomes maturing at near WT kinetics and others exhibiting significantly slower maturation kinetics. The slow-to-mature nucleosomes are enriched in intergenic and poorly transcribed regions, suggesting that transcription-dependent assembly mechanisms can reset the slow-to-mature nucleosomes following replication. Nucleosomes with slow maturation kinetics are also associated with poly(dA:dT) sequences, which implies that CAF-1 deposits histones in a manner that counteracts resistance from the inflexible DNA sequence, promoting the formation of histone octamers as well as ordered nucleosome arrays. In addition, we demonstrate that the delay in chromatin maturation is accompanied by a transient and S-phase specific loss of gene silencing and transcriptional regulation, revealing that the DNA replication program can directly shape the chromatin landscape and modulate gene expression through the process of chromatin maturation.
Collapse
Affiliation(s)
- Boning Chen
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| | - Heather K. MacAlpine
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| | | | - David M. MacAlpine
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710
| |
Collapse
|
17
|
Hermawaty D, Cahn J, Lister R, Considine MJ. Systematic evaluation of chromatin immunoprecipitation sequencing to study histone occupancy in dormancy transitions of grapevine buds. TREE PHYSIOLOGY 2023; 43:675-689. [PMID: 36637421 PMCID: PMC10094961 DOI: 10.1093/treephys/tpac146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 11/17/2022] [Accepted: 12/21/2022] [Indexed: 05/03/2023]
Abstract
The regulation of DNA accessibility by histone modification has emerged as a paradigm of developmental and environmental programming. Chromatin immunoprecipitation followed by sequencing (ChIP-seq) is a versatile tool to investigate in vivo protein-DNA interaction and has enabled advances in mechanistic understanding of physiologies. The technique has been successfully demonstrated in several plant species and tissues; however, it has remained challenging in woody tissues, in particular complex structures such as perennating buds. Here we developed a ChIP method specifically for mature dormant buds of grapevine (Vitis vinifera cv. Cabernet Sauvignon). Each step of the protocol was systematically optimized, including crosslinking, chromatin extraction, sonication and antibody validation. Analysis of histone H3-enriched DNA was performed to evaluate the success of the protocol and identify occupancy of histone H3 along grapevine bud chromatin. To our best knowledge, this is the first ChIP experiment protocol optimized for the grapevine bud system.
Collapse
Affiliation(s)
- Dina Hermawaty
- The UWA Institute of Agriculture, The University of Western Australia, M082/35 Striling Hwy, Perth, WA 6009, Australia
| | - Jonathan Cahn
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, M310/35 Striling Hwy, Perth, WA 6009, Australia
| | - Ryan Lister
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, M310/35 Striling Hwy, Perth, WA 6009, Australia
| | - Michael J Considine
- The UWA Institute of Agriculture, The University of Western Australia, M082/35 Striling Hwy, Perth, WA 6009, Australia
- ARC Centre of Excellence in Plant Energy Biology, The University of Western Australia, M310/35 Striling Hwy, Perth, WA 6009, Australia
- Horticulture and Irrigated Agriculture, Department of Primary Industries and Regional Development, 1 Nash St, Perth, 6000, Australia
| |
Collapse
|
18
|
Luengo-Márquez J, Zalvide-Pombo J, Pérez R, Assenza S. Force-dependent elasticity of nucleic acids. NANOSCALE 2023; 15:6738-6744. [PMID: 36942727 DOI: 10.1039/d2nr06324g] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The functioning of double-stranded (ds) nucleic acids (NAs) in cellular processes is strongly mediated by their elastic response. These processes involve proteins that interact with dsDNA or dsRNA and distort their structures. The perturbation of the elasticity of NAs arising from these deformations is not properly considered by most theoretical frameworks. In this work, we introduce a novel method to assess the impact of mechanical stress on the elastic response of dsDNA and dsRNA through the analysis of the fluctuations of the double helix. Application of this approach to atomistic simulations reveals qualitative differences in the force dependence of the mechanical properties of dsDNA with respect to those of dsRNA, which we relate to structural features of these molecules by means of physically-sound minimalistic models.
Collapse
Affiliation(s)
- Juan Luengo-Márquez
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
- Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Juan Zalvide-Pombo
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
| | - Rubén Pérez
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain.
| | - Salvatore Assenza
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, 28049 Madrid, Spain.
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain.
- Instituto Nicolás Cabrera, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| |
Collapse
|
19
|
Ma X, Fan L, Zhang Z, Yang X, Liu Y, Ma Y, Pan Y, Zhou G, Zhang M, Ning H, Kong F, Ma J, Liu S, Tian Z. Global dissection of the recombination landscape in soybean using a high-density 600K SoySNP array. PLANT BIOTECHNOLOGY JOURNAL 2023; 21:606-620. [PMID: 36458856 PMCID: PMC9946146 DOI: 10.1111/pbi.13975] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 12/09/2022] [Accepted: 11/27/2022] [Indexed: 05/17/2023]
Abstract
Recombination is crucial for crop breeding because it can break linkage drag and generate novel allele combinations. However, the high-resolution recombination landscape and its driving forces in soybean are largely unknown. Here, we constructed eight recombinant inbred line (RIL) populations and genotyped individual lines using the high-density 600K SoySNP array, which yielded a high-resolution recombination map with 5636 recombination sites at a resolution of 1.37 kb. The recombination rate was negatively correlated with transposable element density and GC content but positively correlated with gene density. Interestingly, we found that meiotic recombination was enriched at the promoters of active genes. Further investigations revealed that chromatin accessibility and active epigenetic modifications promoted recombination. Our findings provide important insights into the control of homologous recombination and thus will increase our ability to accelerate soybean breeding by manipulating meiotic recombination rate.
Collapse
Affiliation(s)
- Xin Ma
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy for Seed DesignChinese Academy of SciencesBeijingChina
| | - Lei Fan
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy for Seed DesignChinese Academy of SciencesBeijingChina
| | - Zhifang Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy for Seed DesignChinese Academy of SciencesBeijingChina
| | - Xia Yang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy for Seed DesignChinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Yucheng Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy for Seed DesignChinese Academy of SciencesBeijingChina
| | - Yanming Ma
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy for Seed DesignChinese Academy of SciencesBeijingChina
| | - Yi Pan
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy for Seed DesignChinese Academy of SciencesBeijingChina
| | - Guoan Zhou
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy for Seed DesignChinese Academy of SciencesBeijingChina
| | - Min Zhang
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy for Seed DesignChinese Academy of SciencesBeijingChina
| | - Hailong Ning
- Key Laboratory of Soybean Biology, Chinese Ministry of EducationNortheast Agricultural UniversityHarbinChina
| | - Fanjiang Kong
- Innovative Center of Molecular Genetics and Evolution, School of Life SciencesGuangzhou UniversityGuangzhouChina
| | - Junkui Ma
- The Industrial Crop InstituteShanxi Agricultural UniversityTaiyuanChina
| | - Shulin Liu
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy for Seed DesignChinese Academy of SciencesBeijingChina
| | - Zhixi Tian
- State Key Laboratory of Plant Cell and Chromosome Engineering, Institute of Genetics and Developmental Biology, Innovative Academy for Seed DesignChinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| |
Collapse
|
20
|
Abeyratne CR, Macaya-Sanz D, Zhou R, Barry KW, Daum C, Haiby K, Lipzen A, Stanton B, Yoshinaga Y, Zane M, Tuskan GA, DiFazio SP. High-resolution mapping reveals hotspots and sex-biased recombination in Populus trichocarpa. G3 (BETHESDA, MD.) 2023; 13:jkac269. [PMID: 36250890 PMCID: PMC9836356 DOI: 10.1093/g3journal/jkac269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 09/28/2022] [Indexed: 12/14/2022]
Abstract
Fine-scale meiotic recombination is fundamental to the outcome of natural and artificial selection. Here, dense genetic mapping and haplotype reconstruction were used to estimate recombination for a full factorial Populus trichocarpa cross of 7 males and 7 females. Genomes of the resulting 49 full-sib families (N = 829 offspring) were resequenced, and high-fidelity biallelic SNP/INDELs and pedigree information were used to ascertain allelic phase and impute progeny genotypes to recover gametic haplotypes. The 14 parental genetic maps contained 1,820 SNP/INDELs on average that covered 376.7 Mb of physical length across 19 chromosomes. Comparison of parental and progeny haplotypes allowed fine-scale demarcation of cross-over regions, where 38,846 cross-over events in 1,658 gametes were observed. Cross-over events were positively associated with gene density and negatively associated with GC content and long-terminal repeats. One of the most striking findings was higher rates of cross-overs in males in 8 out of 19 chromosomes. Regions with elevated male cross-over rates had lower gene density and GC content than windows showing no sex bias. High-resolution analysis identified 67 candidate cross-over hotspots spread throughout the genome. DNA sequence motifs enriched in these regions showed striking similarity to those of maize, Arabidopsis, and wheat. These findings, and recombination estimates, will be useful for ongoing efforts to accelerate domestication of this and other biomass feedstocks, as well as future studies investigating broader questions related to evolutionary history, perennial development, phenology, wood formation, vegetative propagation, and dioecy that cannot be studied using annual plant model systems.
Collapse
Affiliation(s)
| | - David Macaya-Sanz
- Department of Forest Ecology & Genetics, CIFOR-INIA, CSIC, Madrid 28040, Spain
| | - Ran Zhou
- Warnell School of Forestry and Natural Resources, Department of Genetics, and Department of Plant Biology, University of Georgia, Athens, GA 30602, USA
| | - Kerrie W Barry
- Department of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | - Christopher Daum
- Department of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | | | - Anna Lipzen
- Department of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | | | - Yuko Yoshinaga
- Department of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | - Matthew Zane
- Department of Energy Joint Genome Institute, Berkeley, CA 94720, USA
| | - Gerald A Tuskan
- Biosciences Division, Center for Bioenergy Innovation, Oak Ridge National Laboratory, Oak Ridge, TN 37830, USA
| | - Stephen P DiFazio
- Department of Biology, West Virginia University, Morgantown, WV 26506, USA
| |
Collapse
|
21
|
Khan SR, Sakib S, Rahman MS, Samee MAH. DeepBend: An interpretable model of DNA bendability. iScience 2023; 26:105945. [PMID: 36866046 PMCID: PMC9971889 DOI: 10.1016/j.isci.2023.105945] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 12/05/2022] [Accepted: 01/05/2023] [Indexed: 01/09/2023] Open
Abstract
The bendability of genomic DNA impacts chromatin packaging and protein-DNA binding. However, we do not have a comprehensive understanding of the motifs influencing DNA bendability. Recent high-throughput technologies such as Loop-Seq offer an opportunity to address this gap but the lack of accurate and interpretable machine learning models still remains. Here we introduce DeepBend, a convolutional neural network model with convolutions designed to directly capture the motifs underlying DNA bendability and their periodic occurrences or relative arrangements that modulate bendability. DeepBend consistently performs on par with alternative models while giving an extra edge through mechanistic interpretations. Besides confirming the known motifs of DNA bendability, DeepBend also revealed several novel motifs and showed how the spatial patterns of motif occurrences influence bendability. DeepBend's genome-wide prediction of bendability further showed how bendability is linked to chromatin conformation and revealed the motifs controlling the bendability of topologically associated domains and their boundaries.
Collapse
Affiliation(s)
- Samin Rahman Khan
- Bangladesh University of Engineering and Technology, Dhaka, Bangladesh
| | - Sadman Sakib
- Bangladesh University of Engineering and Technology, Dhaka, Bangladesh
| | - M. Sohel Rahman
- Bangladesh University of Engineering and Technology, Dhaka, Bangladesh,Corresponding author
| | | |
Collapse
|
22
|
Erkelens AM, Henneman B, van der Valk RA, Kirolos NCS, Dame RT. Specific DNA binding of archaeal histones HMfA and HMfB. Front Microbiol 2023; 14:1166608. [PMID: 37143534 PMCID: PMC10151503 DOI: 10.3389/fmicb.2023.1166608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Accepted: 03/27/2023] [Indexed: 05/06/2023] Open
Abstract
In archaea, histones play a role in genome compaction and are involved in transcription regulation. Whereas archaeal histones bind DNA without sequence specificity, they bind preferentially to DNA containing repeats of alternating A/T and G/C motifs. These motifs are also present on the artificial sequence "Clone20," a high-affinity model sequence for binding of the histones from Methanothermus fervidus. Here, we investigate the binding of HMfA and HMfB to Clone20 DNA. We show that specific binding at low protein concentrations (<30 nM) yields a modest level of DNA compaction, attributed to tetrameric nucleosome formation, whereas nonspecific binding strongly compacts DNA. We also demonstrate that histones impaired in hypernucleosome formation are still able to recognize the Clone20 sequence. Histone tetramers indeed exhibit a higher binding affinity for Clone20 than nonspecific DNA. Our results indicate that a high-affinity DNA sequence does not act as a nucleation site, but is bound by a tetramer which we propose is geometrically different from the hypernucleosome. Such a mode of histone binding might permit sequence-driven modulation of hypernucleosome size. These findings might be extrapolated to histone variants that do not form hypernucleosomes. Versatile binding modes of histones could provide a platform for functional interplay between genome compaction and transcription.
Collapse
Affiliation(s)
| | - Bram Henneman
- Leiden Institute of Chemistry, Leiden University, Leiden, Netherlands
| | | | | | - Remus T. Dame
- Leiden Institute of Chemistry, Leiden University, Leiden, Netherlands
- Centre for Microbial Cell Biology, Leiden University, Leiden, Netherlands
- *Correspondence: Remus T. Dame,
| |
Collapse
|
23
|
Crespo-Piazuelo D, Acloque H, González-Rodríguez O, Mongellaz M, Mercat MJ, Bink MCAM, Huisman AE, Ramayo-Caldas Y, Sánchez JP, Ballester M. Identification of transcriptional regulatory variants in pig duodenum, liver, and muscle tissues. Gigascience 2022; 12:giad042. [PMID: 37354463 PMCID: PMC10290502 DOI: 10.1093/gigascience/giad042] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 04/13/2023] [Accepted: 05/25/2023] [Indexed: 06/26/2023] Open
Abstract
BACKGROUND In humans and livestock species, genome-wide association studies (GWAS) have been applied to study the association between variants distributed across the genome and a phenotype of interest. To discover genetic polymorphisms affecting the duodenum, liver, and muscle transcriptomes of 300 pigs from 3 different breeds (Duroc, Landrace, and Large White), we performed expression GWAS between 25,315,878 polymorphisms and the expression of 13,891 genes in duodenum, 12,748 genes in liver, and 11,617 genes in muscle. RESULTS More than 9.68 × 1011 association tests were performed, yielding 14,096,080 significantly associated variants, which were grouped in 26,414 expression quantitative trait locus (eQTL) regions. Over 56% of the variants were within 1 Mb of their associated gene. In addition to the 100-kb region upstream of the transcription start site, we identified the importance of the 100-kb region downstream of the 3'UTR for gene regulation, as most of the cis-regulatory variants were located within these 2 regions. We also observed 39,874 hotspot regulatory polymorphisms associated with the expression of 10 or more genes that could modify the protein structure or the expression of a regulator gene. In addition, 2 motifs (5'-GATCCNGYGTTGCYG-3' and a poly(A) sequence) were enriched across the 3 tissues within the neighboring sequences of the most significant single-nucleotide polymorphisms in each cis-eQTL region. CONCLUSIONS The 14 million significant associations obtained in this study are publicly available and have enabled the identification of expression-associated cis-, trans-, and hotspot regulatory variants within and across tissues, thus shedding light on the molecular mechanisms of regulatory variations that shape end-trait phenotypes.
Collapse
Affiliation(s)
- Daniel Crespo-Piazuelo
- Animal Breeding and Genetics Program, IRTA, Torre Marimon, Caldes de Montbui (08140), Spain
| | - Hervé Acloque
- GABI, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas (78350), France
| | | | - Mayrone Mongellaz
- GABI, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas (78350), France
| | | | - Marco C A M Bink
- Hendrix Genetics Research Technology & Services B.V., Boxmeer (5830 AC), The Netherlands
| | | | - Yuliaxis Ramayo-Caldas
- Animal Breeding and Genetics Program, IRTA, Torre Marimon, Caldes de Montbui (08140), Spain
| | - Juan Pablo Sánchez
- Animal Breeding and Genetics Program, IRTA, Torre Marimon, Caldes de Montbui (08140), Spain
| | - Maria Ballester
- Animal Breeding and Genetics Program, IRTA, Torre Marimon, Caldes de Montbui (08140), Spain
| |
Collapse
|
24
|
Optical Tweezers to Force Information out of Biological and Synthetic Systems One Molecule at a Time. BIOPHYSICA 2022. [DOI: 10.3390/biophysica2040047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Over the last few decades, in vitro single-molecule manipulation techniques have enabled the use of force and displacement as controlled variables in biochemistry. Measuring the effect of mechanical force on the real-time kinetics of a biological process gives us access to the rates, equilibrium constants and free-energy landscapes of the mechanical steps of the reaction; this information is not accessible by ensemble assays. Optical tweezers are the current method of choice in single-molecule manipulation due to their versatility, high force and spatial and temporal resolutions. The aim of this review is to describe the contributions of our lab in the single-molecule manipulation field. We present here several optical tweezers assays refined in our laboratory to probe the dynamics and mechano-chemical properties of biological molecular motors and synthetic molecular devices at the single-molecule level.
Collapse
|
25
|
A Poly(dA:dT) Tract in the IGF1 Gene Is a Genetic Marker for Growth Traits in Pigs. Animals (Basel) 2022; 12:ani12233316. [PMID: 36496837 PMCID: PMC9738049 DOI: 10.3390/ani12233316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 11/25/2022] [Accepted: 11/25/2022] [Indexed: 11/29/2022] Open
Abstract
Insulin-like growth factor 1 (IGF1) is an important regulator of body growth, development, and metabolism. The poly(dA:dT) tract affects the accessibility of transcription factor binding sites to regulate transcription. Therefore, this study assessed the effects of two poly(dA:dT) tracts on the transcriptional activity of porcine IGF1. The luciferase assay results demonstrated that the poly(dA:dT) tract 2 (−264/−255) was a positive regulatory element for IGF1 gene expression, and the activities between the different lengths of the poly(dA:dT) tract 2 were significant (p<0.01). The transcription factor C/EBPα inhibited the transcription of IGF1 by binding to tract 2, and the expression levels between the lengths of tract 2 after C/EBPα binding were also statistically different (p<0.01). Only the alleles 10T and 11T were found in the tract 2 in commercial pig breeds, while the 9T, 10T, and 11T alleles were found in Chinese native pig breeds. The allele frequencies were in Hardy−Weinberg equilibrium in all pig breeds. The genotypes of tract 2 were significantly associated with the growth traits (days to 115 kg and average daily gain) (p<0.05) in commercial pig breeds. Based on these findings, it can be concluded that the tract 2 mutation could be applied as a candidate genetic marker for growth trait selection in pig breeding programs.
Collapse
|
26
|
Zuiddam M, Shakiba B, Schiessel H. Multiplexing mechanical and translational cues on genes. Biophys J 2022; 121:4311-4324. [PMID: 36230003 PMCID: PMC9703045 DOI: 10.1016/j.bpj.2022.10.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 07/06/2022] [Accepted: 10/07/2022] [Indexed: 12/14/2022] Open
Abstract
The genetic code gives precise instructions on how to translate codons into amino acids. Due to the degeneracy of the genetic code-18 out of 20 amino acids are encoded for by more than one codon-more information can be stored in a basepair sequence. Indeed, various types of additional information have been discussed in the literature, e.g., the positioning of nucleosomes along eukaryotic genomes and the modulation of the translating efficiency in ribosomes to influence cotranslational protein folding. The purpose of this study is to show that it is indeed possible to carry more than one additional layer of information on top of a gene. In particular, we show how much translation efficiency and nucleosome positioning can be adjusted simultaneously without changing the encoded protein. We achieve this by mapping genes on weighted graphs that contain all synonymous genes, and then finding shortest paths through these graphs. This enables us, for example, to readjust the disrupted translational efficiency profile after a gene has been introduced from one organism (e.g., human) into another (e.g., yeast) without greatly changing the nucleosome landscape intrinsically encoded by the DNA molecule.
Collapse
Affiliation(s)
- Martijn Zuiddam
- Institute Lorentz for Theoretical Physics, Leiden University, Leiden, the Netherlands
| | - Bahareh Shakiba
- Institute Lorentz for Theoretical Physics, Leiden University, Leiden, the Netherlands
| | - Helmut Schiessel
- Cluster of Excellence Physics of Life, TU Dresden, Dresden, Germany.
| |
Collapse
|
27
|
Pholtaisong J, Chaiyaratana N, Aporntewan C, Mutirangura A. Mononucleotide A-repeats may Play a Regulatory Role in Endothermic Housekeeping Genes. Evol Bioinform Online 2022; 18:11769343221110656. [PMID: 35860694 PMCID: PMC9290108 DOI: 10.1177/11769343221110656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 07/02/2022] [Indexed: 11/24/2022] Open
Abstract
Background: Coding and non-coding short tandem repeats (STRs) facilitate a great diversity of phenotypic traits. The imbalance of mononucleotide A-repeats around transcription start sites (TSSs) was found in 3 mammals: H. sapiens, M. musculus, and R. norvegicus. Principal Findings: We found that the imbalance pattern originated in some vertebrates. A similar pattern was observed in mammals and birds, but not in amphibians and reptiles. We proposed that the enriched A-repeats upstream of TSSs is a novel hallmark of endotherms or warm-blooded animals. Gene ontology analysis indicates that the primary function of upstream A-repeats involves metabolism, cellular transportation, and sensory perception (smell and chemical stimulus) through housekeeping genes. Conclusions: Upstream A-repeats may play a regulatory role in the metabolic process of endothermic animals.
Collapse
Affiliation(s)
- Jatuphol Pholtaisong
- Program in Bioinformatics and Computational Biology, Graduate School, Chulalongkorn University, Pathumwan, Bangkok, Thailand
| | - Nachol Chaiyaratana
- Department of Electrical and Computer Engineering, Faculty of Engineering, King Mongkut's University of Technology North Bangkok, Bangkok, Thailand.,Division of Medical Genetics Research and Laboratory, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Chatchawit Aporntewan
- Program in Bioinformatics and Computational Biology, Graduate School, Chulalongkorn University, Pathumwan, Bangkok, Thailand.,Department of Mathematics and Computer Science, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok, Thailand.,Omics Sciences and Bioinformatics Center, Chulalongkorn University, Pathumwan, Bangkok, Thailand
| | - Apiwat Mutirangura
- Center of Excellence in Molecular Genetics of Cancer and Human Diseases, Department of Anatomy, Faculty of Medicine, Chulalongkorn University, Pathumwan, Bangkok, Thailand
| |
Collapse
|
28
|
Ruggiero E, Lavezzo E, Grazioli M, Zanin I, Marušič M, Plavec J, Richter SN, Toppo S. Human Virus Genomes Are Enriched in Conserved Adenine/Thymine/Uracil Multiple Tracts That Pause Polymerase Progression. Front Microbiol 2022; 13:915069. [PMID: 35722311 PMCID: PMC9198555 DOI: 10.3389/fmicb.2022.915069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/02/2022] [Indexed: 11/13/2022] Open
Abstract
The DNA secondary structures that deviate from the classic Watson and Crick base pairing are increasingly being reported to form transiently in the cell and regulate specific cellular mechanisms. Human viruses are cell parasites that have evolved mechanisms shared with the host cell to support their own replication and spreading. Contrary to human host cells, viruses display a diverse array of nucleic acid types, which include DNA or RNA in single-stranded or double-stranded conformations. This heterogeneity improves the possible occurrence of non-canonical nucleic acid structures. We have previously shown that human virus genomes are enriched in G-rich sequences that fold in four-stranded nucleic acid secondary structures, the G-quadruplexes.Here, by extensive bioinformatics analysis on all available genomes, we showed that human viruses are enriched in highly conserved multiple A (and T or U) tracts, with such an array that they could in principle form quadruplex structures. By circular dichroism, NMR, and Taq polymerase stop assays, we proved that, while A/T/U-quadruplexes do not form, these tracts still display biological significance, as they invariably trigger polymerase pausing within two bases from the A/T/U tract. “A” bases display the strongest effect. Most of the identified A-tracts are in the coding strand, both at the DNA and RNA levels, suggesting their possible relevance during viral translation. This study expands on the presence and mechanism of nucleic acid secondary structures in human viruses and provides a new direction for antiviral research.
Collapse
Affiliation(s)
| | - Enrico Lavezzo
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Marco Grazioli
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Irene Zanin
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Maja Marušič
- Slovenian NMR Centre, National Institute of Chemistry, Ljubljana, Slovenia
| | - Janez Plavec
- Slovenian NMR Centre, National Institute of Chemistry, Ljubljana, Slovenia
| | - Sara N Richter
- Department of Molecular Medicine, University of Padua, Padua, Italy
| | - Stefano Toppo
- Department of Molecular Medicine, University of Padua, Padua, Italy.,CRIBI Biotechnology Center, University of Padua, Padua, Italy
| |
Collapse
|
29
|
Assenza S, Pérez R. Accurate Sequence-Dependent Coarse-Grained Model for Conformational and Elastic Properties of Double-Stranded DNA. J Chem Theory Comput 2022; 18:3239-3256. [PMID: 35394775 PMCID: PMC9097290 DOI: 10.1021/acs.jctc.2c00138] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
![]()
We introduce MADna,
a sequence-dependent coarse-grained model of
double-stranded DNA (dsDNA), where each nucleotide is described by
three beads localized at the sugar, at the base moiety, and at the
phosphate group, respectively. The sequence dependence is included
by considering a step-dependent parametrization of the bonded interactions,
which are tuned in order to reproduce the values of key observables
obtained from exhaustive atomistic simulations from the literature.
The predictions of the model are benchmarked against an independent
set of all-atom simulations, showing that it captures with high fidelity
the sequence dependence of conformational and elastic features beyond
the single step considered in its formulation. A remarkably good agreement
with experiments is found for both sequence-averaged and sequence-dependent
conformational and elastic features, including the stretching and
torsion moduli, the twist–stretch and twist–bend couplings,
the persistence length, and the helical pitch. Overall, for the inspected
quantities, the model has a precision comparable to atomistic simulations,
hence providing a reliable coarse-grained description for the rationalization
of single-molecule experiments and the study of cellular processes
involving dsDNA. Owing to the simplicity of its formulation, MADna
can be straightforwardly included in common simulation engines. Particularly,
an implementation of the model in LAMMPS is made available on an online
repository to ease its usage within the DNA research community.
Collapse
|
30
|
Han GS, Li Q, Li Y. Nucleosome positioning based on DNA sequence embedding and deep learning. BMC Genomics 2022; 23:301. [PMID: 35418074 PMCID: PMC9006412 DOI: 10.1186/s12864-022-08508-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 03/28/2022] [Indexed: 11/25/2022] Open
Abstract
Background Nucleosome positioning is the precise determination of the location of nucleosomes on DNA sequence. With the continuous advancement of biotechnology and computer technology, biological data is showing explosive growth. It is of practical significance to develop an efficient nucleosome positioning algorithm. Indeed, convolutional neural networks (CNN) can capture local features in DNA sequences, but ignore the order of bases. While the bidirectional recurrent neural network can make up for CNN's shortcomings in this regard and extract the long-term dependent features of DNA sequence. Results In this work, we use word vectors to represent DNA sequences and propose three new deep learning models for nucleosome positioning, and the integrative model NP_CBiR reaches a better prediction performance. The overall accuracies of NP_CBiR on H. sapiens, C. elegans, and D. melanogaster datasets are 86.18%, 89.39%, and 85.55% respectively. Conclusions Benefited by different network structures, NP_CBiR can effectively extract local features and bases order features of DNA sequences, thus can be considered as a complementary tool for nucleosome positioning.
Collapse
Affiliation(s)
- Guo-Sheng Han
- Department of Mathematics and Computational Science, Xiangtan University, Xiangtan, 411105, Hunan, China. .,Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education and Hunan Key Laboratory for Computation and Simulation in Science and Engineering, Xiangtan University, Xiangtan, 411105, Hunan, China.
| | - Qi Li
- Department of Mathematics and Computational Science, Xiangtan University, Xiangtan, 411105, Hunan, China.,Xiangtan Medicine Health Vocational College, Xiangtan, 411102, Hunan, China
| | - Ying Li
- Department of Mathematics and Computational Science, Xiangtan University, Xiangtan, 411105, Hunan, China.,Key Laboratory of Intelligent Computing and Information Processing of Ministry of Education and Hunan Key Laboratory for Computation and Simulation in Science and Engineering, Xiangtan University, Xiangtan, 411105, Hunan, China
| |
Collapse
|
31
|
Trotta E. GC content strongly influences the role of poly(dA) in the intrinsic nucleosome positioning in Saccharomyces cerevisiae. Yeast 2022; 39:262-271. [PMID: 35348238 PMCID: PMC9541940 DOI: 10.1002/yea.3701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 11/08/2022] Open
Abstract
The nucleosome is the basic structural element of genomic DNA packaging and plays a role in transcription, replication, and recombination. Poly(dA) tracts are considered major sequence determinants of nucleosome positioning, although their role is not well understood. Here, we show that the homopolymeric character and the low GC content of poly(dA)s play different roles in nucleosome formation. We found that the inherent low GC content of poly(dA) alone can account for the deep and anisotropic nucleosome depletion at structurally and functionally important regions of promoters and origins of replication. We also show that the level of nucleosome occupancy at poly(dA) is strongly related to the local nucleotide background and its high frequency of occurrence in Saccharomyces cerevisiae does not appear merely to be associated with its intrinsic nucleosome-excluding properties. In addition, we show that the GC content alone can predict more than 60% of the in vitro nucleosome map, providing further evidence that the intrinsic nucleosome positioning is more greatly determined by GC content than poly(dA) stretches. Our results are consistent with a model in which poly(dA) stretches act at two distinct levels: first, by its low GC content, which intrinsically contributes to hinder nucleosome formation, and second, by its contiguous runs of dA that selectively drive the recruitment of non-histone proteins with structural and functional roles.
Collapse
Affiliation(s)
- Edoardo Trotta
- Institute of Translational Pharmacology, Consiglio Nazionale delle Ricerche (CNR), Rome, Italy
| |
Collapse
|
32
|
Li F, Wang M, Chi Z, Zhang Z, Wang X, Xing M, Chi Z, Liu G. A novel transcriptional activation mechanism of inulinase gene in Kluyveromyces marxianus involving a glycolysis regulator KmGcr1p with unique and functional Q-rich repeats. Mol Microbiol 2022; 117:1063-1079. [PMID: 35218085 DOI: 10.1111/mmi.14889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 11/28/2022]
Abstract
Kluyveromyces marxianus is the most suitable fungus for inulinase industrial production. However, the underlying transcriptional activation mechanism of the inulinase gene (INU1) is hitherto unclear. Here, we undertook genetic and biochemical analyses to elucidate that a glycolysis regulator KmGcr1p with unique Q-rich repeats is the key transcriptional activator of INU1. We determined that INU1 and glycolytic genes share similar transcriptional activation patterns, and that inulinase activity is induced by fermentable carbon sources including the hydrolysis products of inulin (fructose and glucose), which suggests a novel model of product feedback activation. Furthermore, all four CT-boxes in the INU1 promoter are important for KmGcr1p DNA binding in vitro, but the most downstream CT-box 1 primarily confers upstream activating sequence activity in vivo. More intriguingly, the use of artificial and natural GCR1 mutants suggests that the Q-rich repeats act as a functional module to maintain KmGcr1p transcriptional activity by contributing to its solubility and DNA binding affinity. Altogether, this study uncovers a novel transcriptional activation mechanism for the inulinase gene that is different from the previous understanding for filamentous fungi, but might have universal significance among inulinase-producing yeasts, thereby leading to a better understanding of the regulation mechanism of yeast inulinase genes.
Collapse
Affiliation(s)
- Fengyi Li
- College of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, Shandong, China
| | - Mengqi Wang
- College of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, Shandong, China
| | - Zhe Chi
- College of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, Shandong, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| | - Zhaoxuan Zhang
- College of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, Shandong, China
| | - Xiaoxiang Wang
- College of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, Shandong, China
| | - Mengdan Xing
- College of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, Shandong, China
| | - Zhenming Chi
- College of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, Shandong, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, China
| | - Guanglei Liu
- College of Marine Life Science, Ocean University of China, Yushan Road, No. 5, Qingdao, Shandong, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Key Laboratory of Marine Genetics and Breeding (Ocean University of China), Ministry of Education, Qingdao, China
| |
Collapse
|
33
|
Chaudhary A, Singh D. In-silico analysis of the regulatory region of effector protein genes in Verticillium dahliae. GENE REPORTS 2022. [DOI: 10.1016/j.genrep.2022.101533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
34
|
Han S, Lee H, Lee AJ, Kim SK, Jung I, Koh GY, Kim TK, Lee D. CHD4 Conceals Aberrant CTCF-Binding Sites at TAD Interiors by Regulating Chromatin Accessibility in Mouse Embryonic Stem Cells. Mol Cells 2021; 44:805-829. [PMID: 34764232 PMCID: PMC8627837 DOI: 10.14348/molcells.2021.0224] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 09/06/2021] [Indexed: 11/27/2022] Open
Abstract
CCCTC-binding factor (CTCF) critically contributes to 3D chromatin organization by determining topologically associated domain (TAD) borders. Although CTCF primarily binds at TAD borders, there also exist putative CTCF-binding sites within TADs, which are spread throughout the genome by retrotransposition. However, the detailed mechanism responsible for masking the putative CTCF-binding sites remains largely elusive. Here, we show that the ATP-dependent chromatin remodeler, chromodomain helicase DNA-binding 4 (CHD4), regulates chromatin accessibility to conceal aberrant CTCF-binding sites embedded in H3K9me3-enriched heterochromatic B2 short interspersed nuclear elements (SINEs) in mouse embryonic stem cells (mESCs). Upon CHD4 depletion, these aberrant CTCF-binding sites become accessible and aberrant CTCF recruitment occurs within TADs, resulting in disorganization of local TADs. RNA-binding intrinsically disordered domains (IDRs) of CHD4 are required to prevent this aberrant CTCF binding, and CHD4 is critical for the repression of B2 SINE transcripts. These results collectively reveal that a CHD4-mediated mechanism ensures appropriate CTCF binding and associated TAD organization in mESCs.
Collapse
Affiliation(s)
- Sungwook Han
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Hosuk Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
- Center for Vascular Research, Institute for Basic Sciences, Daejeon 34141, Korea
| | - Andrew J. Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Seung-Kyoon Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Inkyung Jung
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| | - Gou Young Koh
- Center for Vascular Research, Institute for Basic Sciences, Daejeon 34141, Korea
| | - Tae-Kyung Kim
- Department of Life Sciences, Pohang University of Science and Technology, Pohang 37673, Korea
| | - Daeyoup Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea
| |
Collapse
|
35
|
Guo S, Lin S. mRNA alternative polyadenylation (APA) in regulation of gene expression and diseases. Genes Dis 2021; 10:165-174. [PMID: 37013028 PMCID: PMC10066270 DOI: 10.1016/j.gendis.2021.09.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 08/26/2021] [Accepted: 09/07/2021] [Indexed: 11/16/2022] Open
Abstract
The mRNA polyadenylation plays essential function in regulation of mRNA metabolism. Mis-regulations of mRNA polyadenylation are frequently linked with aberrant gene expression and disease progression. Under the action of polyadenylate polymerase, poly(A) tail is synthesized after the polyadenylation signal (PAS) sites on the mRNAs. Alternative polyadenylation (APA) often occurs in mRNAs with multiple poly(A) sites, producing different 3' ends for transcript variants, and therefore plays important functions in gene expression regulation. In this review, we first summarize the classical process of mRNA 3'-terminal formation and discuss the length control mechanisms of poly(A) in nucleus and cytoplasm. Then we review the research progress on alternative polyadenylation regulation and the APA site selection mechanism. Finally, we summarize the functional roles of APA in the regulation of gene expression and diseases including cancers.
Collapse
Affiliation(s)
- Siyao Guo
- Center for Translational Medicine, Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong 510060, China
| | - Shuibin Lin
- Center for Translational Medicine, Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
- State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong 510060, China
- Corresponding author. Center for Translational Medicine, Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
| |
Collapse
|
36
|
Barnes T, Korber P. The Active Mechanism of Nucleosome Depletion by Poly(dA:dT) Tracts In Vivo. Int J Mol Sci 2021; 22:ijms22158233. [PMID: 34360997 PMCID: PMC8347975 DOI: 10.3390/ijms22158233] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 07/27/2021] [Accepted: 07/29/2021] [Indexed: 12/16/2022] Open
Abstract
Poly(dA:dT) tracts cause nucleosome depletion in many species, e.g., at promoters and replication origins. Their intrinsic biophysical sequence properties make them stiff and unfavorable for nucleosome assembly, as probed by in vitro nucleosome reconstitution. The mere correlation between nucleosome depletion over poly(dA:dT) tracts in in vitro reconstituted and in in vivo chromatin inspired an intrinsic nucleosome exclusion mechanism in vivo that is based only on DNA and histone properties. However, we compile here published and new evidence that this correlation does not reflect mechanistic causation. (1) Nucleosome depletion over poly(dA:dT) in vivo is not universal, e.g., very weak in S. pombe. (2) The energy penalty for incorporating poly(dA:dT) tracts into nucleosomes is modest (<10%) relative to ATP hydrolysis energy abundantly invested by chromatin remodelers. (3) Nucleosome depletion over poly(dA:dT) is much stronger in vivo than in vitro if monitored without MNase and (4) actively maintained in vivo. (5) S. cerevisiae promoters evolved a strand-biased poly(dA) versus poly(dT) distribution. (6) Nucleosome depletion over poly(dA) is directional in vivo. (7) The ATP dependent chromatin remodeler RSC preferentially and directionally displaces nucleosomes towards 5′ of poly(dA). Especially distribution strand bias and displacement directionality would not be expected for an intrinsic mechanism. Together, this argues for an in vivo mechanism where active and species-specific read out of intrinsic sequence properties, e.g., by remodelers, shapes nucleosome organization.
Collapse
|
37
|
Brandani GB, Tan C, Takada S. The kinetic landscape of nucleosome assembly: A coarse-grained molecular dynamics study. PLoS Comput Biol 2021; 17:e1009253. [PMID: 34314440 PMCID: PMC8345847 DOI: 10.1371/journal.pcbi.1009253] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 08/06/2021] [Accepted: 07/06/2021] [Indexed: 11/23/2022] Open
Abstract
The organization of nucleosomes along the Eukaryotic genome is maintained over time despite disruptive events such as replication. During this complex process, histones and DNA can form a variety of non-canonical nucleosome conformations, but their precise molecular details and roles during nucleosome assembly remain unclear. In this study, employing coarse-grained molecular dynamics simulations and Markov state modeling, we characterized the complete kinetics of nucleosome assembly. On the nucleosome-positioning 601 DNA sequence, we observe a rich transition network among various canonical and non-canonical tetrasome, hexasome, and nucleosome conformations. A low salt environment makes nucleosomes stable, but the kinetic landscape becomes more rugged, so that the system is more likely to be trapped in off-pathway partially assembled intermediates. Finally, we find that the co-operativity between DNA bending and histone association enables positioning sequence motifs to direct the assembly process, with potential implications for the dynamic organization of nucleosomes on real genomic sequences. Nucleosomes are biomolecular complexes formed by DNA wrapped around histone proteins. They represent the basic units of Eukaryotic chromosomes, compacting the genome so that it fits into the small nucleus, and regulating important biological processes such as gene expression. Nucleosomes are disassembled during disruptive events such as DNA replication, and re-assembled afterwards to preserve the correct organization of chromatin. However, the molecular details of nucleosome assembly are still not well understood. In particular, experiments found that histones and DNA may associate into a variety of non-canonical complexes, but their precise conformation and role during assembly remain unclear. In this study, we addressed these problems by performing extensive molecular dynamics simulations of nucleosomes undergoing assembly and disassembly. The simulations reveal many insights into the kinetics of assembly, the structure of non-canonical nucleosome intermediates, and the influence of salt concentration and DNA sequence on the assembly process.
Collapse
Affiliation(s)
- Giovanni B. Brandani
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
- * E-mail: (GBB); (ST)
| | - Cheng Tan
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
| | - Shoji Takada
- Department of Biophysics, Graduate School of Science, Kyoto University, Kyoto, Japan
- * E-mail: (GBB); (ST)
| |
Collapse
|
38
|
Abstract
DNA dynamics can only be understood by taking into account its complex mechanical behavior at different length scales. At the micrometer level, the mechanical properties of single DNA molecules have been well-characterized by polymer models and are commonly quantified by a persistence length of 50 nm (~150 bp). However, at the base pair level (~3.4 Å), the dynamics of DNA involves complex molecular mechanisms that are still being deciphered. Here, we review recent single-molecule experiments and molecular dynamics simulations that are providing novel insights into DNA mechanics from such a molecular perspective. We first discuss recent findings on sequence-dependent DNA mechanical properties, including sequences that resist mechanical stress and sequences that can accommodate strong deformations. We then comment on the intricate effects of cytosine methylation and DNA mismatches on DNA mechanics. Finally, we review recently reported differences in the mechanical properties of DNA and double-stranded RNA, the other double-helical carrier of genetic information. A thorough examination of the recent single-molecule literature permits establishing a set of general 'rules' that reasonably explain the mechanics of nucleic acids at the base pair level. These simple rules offer an improved description of certain biological systems and might serve as valuable guidelines for future design of DNA and RNA nanostructures.
Collapse
|
39
|
Discovery of widespread transcription initiation at microsatellites predictable by sequence-based deep neural network. Nat Commun 2021; 12:3297. [PMID: 34078885 PMCID: PMC8172540 DOI: 10.1038/s41467-021-23143-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 04/13/2021] [Indexed: 02/04/2023] Open
Abstract
Using the Cap Analysis of Gene Expression (CAGE) technology, the FANTOM5 consortium provided one of the most comprehensive maps of transcription start sites (TSSs) in several species. Strikingly, ~72% of them could not be assigned to a specific gene and initiate at unconventional regions, outside promoters or enhancers. Here, we probe these unassigned TSSs and show that, in all species studied, a significant fraction of CAGE peaks initiate at microsatellites, also called short tandem repeats (STRs). To confirm this transcription, we develop Cap Trap RNA-seq, a technology which combines cap trapping and long read MinION sequencing. We train sequence-based deep learning models able to predict CAGE signal at STRs with high accuracy. These models unveil the importance of STR surrounding sequences not only to distinguish STR classes, but also to predict the level of transcription initiation. Importantly, genetic variants linked to human diseases are preferentially found at STRs with high transcription initiation level, supporting the biological and clinical relevance of transcription initiation at STRs. Together, our results extend the repertoire of non-coding transcription associated with DNA tandem repeats and complexify STR polymorphism.
Collapse
|
40
|
Accurate modeling of DNA conformational flexibility by a multivariate Ising model. Proc Natl Acad Sci U S A 2021; 118:2021263118. [PMID: 33876759 DOI: 10.1073/pnas.2021263118] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The sequence-dependent structure and deformability of DNA play a major role for binding of proteins and regulation of gene expression. So far, most efforts to model DNA flexibility are based on unimodal harmonic stiffness models at base-pair resolution. However, multimodal behavior due to distinct conformational substates also contributes significantly to the conformational flexibility of DNA. Moreover, these local substates are correlated to their nearest-neighbor substates. A description for DNA elasticity which includes both multimodality and nearest-neighbor coupling has remained a challenge, which we solve by combining our multivariate harmonic approximation with an Ising model for the substates. In a series of applications to DNA fluctuations and protein-DNA complexes, we demonstrate substantial improvements over the unimodal stiffness model. Furthermore, our multivariate Ising model reveals a mechanical destabilization for adenine (A)-tracts to undergo nucleosome formation. Our approach offers a wide range of applications to determine sequence-dependent deformation energies of DNA and to investigate indirect readout contributions to protein-DNA recognition.
Collapse
|
41
|
Menichelli C, Guitard V, Martins RM, Lèbre S, Lopez-Rubio JJ, Lecellier CH, Bréhélin L. Identification of long regulatory elements in the genome of Plasmodium falciparum and other eukaryotes. PLoS Comput Biol 2021; 17:e1008909. [PMID: 33861755 PMCID: PMC8081344 DOI: 10.1371/journal.pcbi.1008909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 04/28/2021] [Accepted: 03/24/2021] [Indexed: 01/15/2023] Open
Abstract
Long regulatory elements (LREs), such as CpG islands, polydA:dT tracts or AU-rich elements, are thought to play key roles in gene regulation but, as opposed to conventional binding sites of transcription factors, few methods have been proposed to formally and automatically characterize them. We present here a computational approach named DExTER (Domain Exploration To Explain gene Regulation) dedicated to the identification of candidate LREs (cLREs) and apply it to the analysis of the genomes of P. falciparum and other eukaryotes. Our analyses show that all tested genomes contain several cLREs that are somewhat conserved along evolution, and that gene expression can be predicted with surprising accuracy on the basis of these long regions only. Regulation by cLREs exhibits very different behaviours depending on species and conditions. In P. falciparum and other Apicomplexan organisms as well as in Dictyostelium discoideum, the process appears highly dynamic, with different cLREs involved at different phases of the life cycle. For multicellular organisms, the same cLREs are involved in all tissues, but a dynamic behavior is observed along embryonic development stages. In P. falciparum, whose genome is known to be strongly depleted of transcription factors, cLREs are predictive of expression with an accuracy above 70%, and our analyses show that they are associated with both transcriptional and post-transcriptional regulation signals. Moreover, we assessed the biological relevance of one LRE discovered by DExTER in P. falciparum using an in vivo reporter assay. The source code (python) of DExTER is available at https://gite.lirmm.fr/menichelli/DExTER.
Collapse
Affiliation(s)
| | - Vincent Guitard
- Laboratory of Pathogen-Host Interactions (LPHI), UMR5235, CNRS, Montpellier University, INSERM, Montpellier, France
| | - Rafael M. Martins
- Laboratory of Pathogen-Host Interactions (LPHI), UMR5235, CNRS, Montpellier University, INSERM, Montpellier, France
| | - Sophie Lèbre
- IMAG, Univ. Montpellier, CNRS, Montpellier, France
- Univ. Paul-Valéry-Montpellier 3, Montpellier, France
| | - Jose-Juan Lopez-Rubio
- Laboratory of Pathogen-Host Interactions (LPHI), UMR5235, CNRS, Montpellier University, INSERM, Montpellier, France
| | - Charles-Henri Lecellier
- LIRMM, Univ Montpellier, CNRS, Montpellier, France
- Institut de Génétique Moléculaire de Montpellier, University of Montpellier, CNRS, Montpellier, France
| | | |
Collapse
|
42
|
Brouwer T, Pham C, Kaczmarczyk A, de Voogd WJ, Botto M, Vizjak P, Mueller-Planitz F, van Noort J. A critical role for linker DNA in higher-order folding of chromatin fibers. Nucleic Acids Res 2021; 49:2537-2551. [PMID: 33589918 PMCID: PMC7969035 DOI: 10.1093/nar/gkab058] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 12/04/2020] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Nucleosome-nucleosome interactions drive the folding of nucleosomal arrays into dense chromatin fibers. A better physical account of the folding of chromatin fibers is necessary to understand the role of chromatin in regulating DNA transactions. Here, we studied the unfolding pathway of regular chromatin fibers as a function of single base pair increments in linker length, using both rigid base-pair Monte Carlo simulations and single-molecule force spectroscopy. Both computational and experimental results reveal a periodic variation of the folding energies due to the limited flexibility of the linker DNA. We show that twist is more restrictive for nucleosome stacking than bend, and find the most stable stacking interactions for linker lengths of multiples of 10 bp. We analyzed nucleosomes stacking in both 1- and 2-start topologies and show that stacking preferences are determined by the length of the linker DNA. Moreover, we present evidence that the sequence of the linker DNA also modulates nucleosome stacking and that the effect of the deletion of the H4 tail depends on the linker length. Importantly, these results imply that nucleosome positioning in vivo not only affects the phasing of nucleosomes relative to DNA but also directs the higher-order structure of chromatin.
Collapse
Affiliation(s)
- Thomas Brouwer
- Biological and Soft Matter Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
| | - Chi Pham
- Biological and Soft Matter Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
| | - Artur Kaczmarczyk
- Biological and Soft Matter Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
| | - Willem-Jan de Voogd
- Biological and Soft Matter Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
| | - Margherita Botto
- Biological and Soft Matter Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
| | - Petra Vizjak
- Biomedical Center, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany
| | - Felix Mueller-Planitz
- Biomedical Center, Ludwig-Maximilians-Universität München, 82152 Martinsried, Germany.,Institute of Physiological Chemistry, Faculty of Medicine Carl Gustav Carus, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany
| | - John van Noort
- Biological and Soft Matter Physics, Huygens-Kamerlingh Onnes Laboratory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
| |
Collapse
|
43
|
D'Oliveira Albanus R, Kyono Y, Hensley J, Varshney A, Orchard P, Kitzman JO, Parker SCJ. Chromatin information content landscapes inform transcription factor and DNA interactions. Nat Commun 2021; 12:1307. [PMID: 33637709 PMCID: PMC7910283 DOI: 10.1038/s41467-021-21534-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Accepted: 01/29/2021] [Indexed: 01/31/2023] Open
Abstract
Interactions between transcription factors and chromatin are fundamental to genome organization and regulation and, ultimately, cell state. Here, we use information theory to measure signatures of organized chromatin resulting from transcription factor-chromatin interactions encoded in the patterns of the accessible genome, which we term chromatin information enrichment (CIE). We calculate CIE for hundreds of transcription factor motifs across human samples and identify two classes: low and high CIE. The 10-20% of common and tissue-specific high CIE transcription factor motifs, associate with higher protein-DNA residence time, including different binding site subclasses of the same transcription factor, increased nucleosome phasing, specific protein domains, and the genetic control of both chromatin accessibility and gene expression. These results show that variations in the information encoded in chromatin architecture reflect functional biological variation, with implications for cell state dynamics and memory.
Collapse
Affiliation(s)
| | - Yasuhiro Kyono
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, USA
- Department of Human Genetics, University of Michigan, Ann Arbor, USA
- Tempus Labs, Inc. Chicago, IL, Chicago, USA
| | - John Hensley
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, USA
| | - Arushi Varshney
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, USA
| | - Peter Orchard
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, USA
| | - Jacob O Kitzman
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, USA
- Department of Human Genetics, University of Michigan, Ann Arbor, USA
| | - Stephen C J Parker
- Department of Computational Medicine & Bioinformatics, University of Michigan, Ann Arbor, USA.
- Department of Human Genetics, University of Michigan, Ann Arbor, USA.
| |
Collapse
|
44
|
Gamarra N, Narlikar GJ. Collaboration through chromatin: motors of transcription and chromatin structure. J Mol Biol 2021; 433:166876. [PMID: 33556407 DOI: 10.1016/j.jmb.2021.166876] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 01/09/2023]
Abstract
Packaging of the eukaryotic genome into chromatin places fundamental physical constraints on transcription. Clarifying how transcription operates within these constraints is essential to understand how eukaryotic gene expression programs are established and maintained. Here we review what is known about the mechanisms of transcription on chromatin templates. Current models indicate that transcription through chromatin is accomplished by the combination of an inherent nucleosome disrupting activity of RNA polymerase and the action of ATP-dependent chromatin remodeling motors. Collaboration between these two types of molecular motors is proposed to occur at all stages of transcription through diverse mechanisms. Further investigation of how these two motors combine their basic activities is essential to clarify the interdependent relationship between genome structure and transcription.
Collapse
Affiliation(s)
- Nathan Gamarra
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States; TETRAD Graduate Program, University of California, San Francisco, San Francisco, United States
| | - Geeta J Narlikar
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States.
| |
Collapse
|
45
|
Routhier E, Pierre E, Khodabandelou G, Mozziconacci J. Genome-wide prediction of DNA mutation effect on nucleosome positions for yeast synthetic genomics. Genome Res 2021; 31:317-326. [PMID: 33355297 PMCID: PMC7849406 DOI: 10.1101/gr.264416.120] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 12/11/2020] [Indexed: 12/15/2022]
Abstract
Genetically modified genomes are often used today in many areas of fundamental and applied research. In many studies, coding or noncoding regions are modified in order to change protein sequences or gene expression levels. Modifying one or several nucleotides in a genome can also lead to unexpected changes in the epigenetic regulation of genes. When designing a synthetic genome with many mutations, it would thus be very informative to be able to predict the effect of these mutations on chromatin. We develop here a deep learning approach that quantifies the effect of every possible single mutation on nucleosome positions on the full Saccharomyces cerevisiae genome. This type of annotation track can be used when designing a modified S. cerevisiae genome. We further highlight how this track can provide new insights on the sequence-dependent mechanisms that drive nucleosomes' positions in vivo.
Collapse
Affiliation(s)
- Etienne Routhier
- Sorbonne Universite, CNRS, Laboratoire de Physique Théorique de la Matière Condensée, LPTMC, Paris F-75252, France
| | - Edgard Pierre
- Sorbonne Universite, CNRS, Laboratoire de Physique Théorique de la Matière Condensée, LPTMC, Paris F-75252, France
| | | | - Julien Mozziconacci
- Sorbonne Universite, CNRS, Laboratoire de Physique Théorique de la Matière Condensée, LPTMC, Paris F-75252, France
- Muséum National d'Histoire Naturelle, Structure et Instabilité des Génomes, UMR7196, Paris 75231, France
- Institut Universitaire de France, Paris 75005, France
| |
Collapse
|
46
|
Kharerin H, Bai L. Thermodynamic modeling of genome-wide nucleosome depleted regions in yeast. PLoS Comput Biol 2021; 17:e1008560. [PMID: 33428627 PMCID: PMC7822557 DOI: 10.1371/journal.pcbi.1008560] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 01/22/2021] [Accepted: 11/25/2020] [Indexed: 01/09/2023] Open
Abstract
Nucleosome positioning in the genome is essential for the regulation of many nuclear processes. We currently have limited capability to predict nucleosome positioning in vivo, especially the locations and sizes of nucleosome depleted regions (NDRs). Here, we present a thermodynamic model that incorporates the intrinsic affinity of histones, competitive binding of sequence-specific factors, and nucleosome remodeling to predict nucleosome positioning in budding yeast. The model shows that the intrinsic affinity of histones, at near-saturating histone concentration, is not sufficient in generating NDRs in the genome. However, the binding of a few factors, especially RSC towards GC-rich and poly(A/T) sequences, allows us to predict ~ 66% of genome-wide NDRs. The model also shows that nucleosome remodeling activity is required to predict the correct NDR sizes. The validity of the model was further supported by the agreement between the predicted and the measured nucleosome positioning upon factor deletion or on exogenous sequences introduced into yeast. Overall, our model quantitatively evaluated the impact of different genetic components on NDR formation and illustrated the vital roles of sequence-specific factors and nucleosome remodeling in this process. Nucleosome is the basic unit of chromatin, containing 147 base-pairs of DNA wrapped around a histone core. The positioning of nucleosomes, i.e., which parts of DNA are inside nucleosome and which parts are nucleosome-free, is highly regulated. In particular, regulatory sequences tend to be exposed in nucleosome-depleted regions (NDRs), and such exposure is crucial for a variety of processes including DNA replication, repair, and gene expression. Here, we used a thermodynamics model to predict nucleosome positioning on the yeast genome. The model shows that the intrinsic sequence preference of histones is not sufficient in generating NDRs. In contrast, binding of a few transcription factors, especially RSC, is largely responsible for NDR formation. Nucleosome remodeling activity is also required in the model to recapitulate the NDR sizes. This model contributes to our understanding of the mechanisms that regulate nucleosome positioning. It can also be used to predict nucleosome positioning in mutant yeast or on novel DNA sequences.
Collapse
Affiliation(s)
- Hungyo Kharerin
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, Pennsylvania, United States of America
| | - Lu Bai
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Center for Eukaryotic Gene Regulation, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- Department of Physics, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
47
|
Jiang Z, Zhang B. On the role of transcription in positioning nucleosomes. PLoS Comput Biol 2021; 17:e1008556. [PMID: 33417594 PMCID: PMC7819601 DOI: 10.1371/journal.pcbi.1008556] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 01/21/2021] [Accepted: 11/23/2020] [Indexed: 12/12/2022] Open
Abstract
Nucleosome positioning is crucial for the genome’s function. Though the role of DNA sequence in positioning nucleosomes is well understood, a detailed mechanistic understanding on the impact of transcription remains lacking. Using numerical simulations, we investigated the dependence of nucleosome density profiles on transcription level across multiple species. We found that the low nucleosome affinity of yeast, but not mouse, promoters contributes to the formation of phased nucleosomes arrays for inactive genes. For the active genes, a heterogeneous distribution of +1 nucleosomes, caused by a tug-of-war between two types of remodeling enzymes, is essential for reproducing their density profiles. In particular, while positioning enzymes are known to remodel the +1 nucleosome and align it toward the transcription start site (TSS), spacer enzymes that use a pair of nucleosomes as their substrate can shift the nucleosome array away from the TSS. Competition between these enzymes results in two types of nucleosome density profiles with well- and ill-positioned +1 nucleosome. Finally, we showed that Pol II assisted histone exchange, if occurring at a fast speed, can abolish the impact of remodeling enzymes. By elucidating the role of individual factors, our study reconciles the seemingly conflicting results on the overall impact of transcription in positioning nucleosomes across species. Nucleosome positioning plays a key role in the genome’s function by regulating the accessibility of protein binding sites as well as higher-order chromatin organization. Though significant progress has been made towards studying the role of DNA sequence in positioning the nucleosomes, our understanding on the impact of transcription lags behind. Our study uses kinetic simulations to explore the role of DNA sequence specificity, transcription factor binding, enzyme remodeling, and Pol II elongation in positioning nucleosomes. It suggests that the differences in nucleosome density profiles observed at various transcription levels in yeast and mouse embryonic stem cells can be understood from a tug-of-war between two types of remodeling enzymes.
Collapse
Affiliation(s)
- Zhongling Jiang
- Departments of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Bin Zhang
- Departments of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
- * E-mail:
| |
Collapse
|
48
|
Abstract
Mechanical deformations of DNA such as bending are ubiquitous and implicated in diverse cellular functions1. However, the lack of high-throughput tools to directly measure the mechanical properties of DNA limits our understanding of whether and how DNA sequences modulate DNA mechanics and associated chromatin transactions genome-wide. We developed an assay called loop-seq to measure the intrinsic cyclizability of DNA – a proxy for DNA bendability – in high throughput. We measured the intrinsic cyclizabilities of 270,806 50 bp DNA fragments that span the entire length of S. cerevisiae chromosome V and other genomic regions, and also include random sequences. We discovered sequence-encoded regions of unusually low bendability upstream of Transcription Start Sites (TSSs). These regions disfavor the sharp DNA bending required for nucleosome formation and are co-centric with known Nucleosome Depleted Regions (NDRs). We show biochemically that low bendability of linker DNA located about 40 bp away from a nucleosome edge inhibits nucleosome sliding into the linker by the chromatin remodeler INO80. The observation explains how INO80 can create promoter-proximal nucleosomal arrays in the absence of any other factors2 by reading the DNA mechanical landscape. We show that chromosome wide, nucleosomes are characterized by high DNA bendability near dyads and low bendability near the linkers. This contrast increases for nucleosomes deeper into gene bodies, suggesting that DNA mechanics plays a previously unappreciated role in organizing nucleosomes far from the TSS, where nucleosome remodelers predominate. Importantly, random substitution of synonymous codons does not preserve this contrast, suggesting that the evolution of codon choice has been impacted by selective pressure to preserve sequence-encoded mechanical modulations along genes. We also provide evidence that transcription through the TSS-proximal nucleosomes is impacted by local DNA mechanics. Overall, this first genome-scale map of DNA mechanics hints at a ‘mechanical code’ with broad functional implications.
Collapse
|
49
|
Jenull S, Tscherner M, Mair T, Kuchler K. ATAC-Seq Identifies Chromatin Landscapes Linked to the Regulation of Oxidative Stress in the Human Fungal Pathogen Candida albicans. J Fungi (Basel) 2020; 6:jof6030182. [PMID: 32967096 PMCID: PMC7559329 DOI: 10.3390/jof6030182] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 12/12/2022] Open
Abstract
Human fungal pathogens often encounter fungicidal stress upon host invasion, but they can swiftly adapt by transcriptional reprogramming that enables pathogen survival. Fungal immune evasion is tightly connected to chromatin regulation. Hence, fungal chromatin modifiers pose alternative treatment options to combat fungal infections. Here, we present an assay for transposase-accessible chromatin using sequencing (ATAC-seq) protocol adapted for the opportunistic pathogen Candida albicans to gain further insight into the interplay of chromatin accessibility and gene expression mounted during fungal adaptation to oxidative stress. The ATAC-seq workflow not only facilitates the robust detection of genomic regions with accessible chromatin but also allows for the precise modeling of nucleosome positions in C. albicans. Importantly, the data reveal genes with altered chromatin accessibility in upstream regulatory regions, which correlate with transcriptional regulation during oxidative stress. Interestingly, many genes show increased chromatin accessibility without change in gene expression upon stress exposure. Such chromatin signatures could predict yet unknown regulatory factors under highly dynamic transcriptional control. Additionally, de novo motif analysis in genomic regions with increased chromatin accessibility upon H2O2 treatment shows significant enrichment for Cap1 binding sites, a major factor of oxidative stress responses in C. albicans. Taken together, the ATAC-seq workflow enables the identification of chromatin signatures and highlights the dynamics of regulatory mechanisms mediating environmental adaptation of C. albicans.
Collapse
|
50
|
Marin-Gonzalez A, Pastrana CL, Bocanegra R, Martín-González A, Vilhena JG, Pérez R, Ibarra B, Aicart-Ramos C, Moreno-Herrero F. Understanding the paradoxical mechanical response of in-phase A-tracts at different force regimes. Nucleic Acids Res 2020; 48:5024-5036. [PMID: 32282908 PMCID: PMC7229863 DOI: 10.1093/nar/gkaa225] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 03/23/2020] [Accepted: 03/25/2020] [Indexed: 12/31/2022] Open
Abstract
A-tracts are A:T rich DNA sequences that exhibit unique structural and mechanical properties associated with several functions in vivo. The crystallographic structure of A-tracts has been well characterized. However, the mechanical properties of these sequences is controversial and their response to force remains unexplored. Here, we rationalize the mechanical properties of in-phase A-tracts present in the Caenorhabditis elegans genome over a wide range of external forces, using single-molecule experiments and theoretical polymer models. Atomic Force Microscopy imaging shows that A-tracts induce long-range (∼200 nm) bending, which originates from an intrinsically bent structure rather than from larger bending flexibility. These data are well described with a theoretical model based on the worm-like chain model that includes intrinsic bending. Magnetic tweezers experiments show that the mechanical response of A-tracts and arbitrary DNA sequences have a similar dependence with monovalent salt supporting that the observed A-tract bend is intrinsic to the sequence. Optical tweezers experiments reveal a high stretch modulus of the A-tract sequences in the enthalpic regime. Our work rationalizes the complex multiscale flexibility of A-tracts, providing a physical basis for the versatile character of these sequences inside the cell.
Collapse
Affiliation(s)
- Alberto Marin-Gonzalez
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, 28049 Cantoblanco, Madrid, Spain
| | - Cesar L Pastrana
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, 28049 Cantoblanco, Madrid, Spain
| | - Rebeca Bocanegra
- IMDEA Nanociencia, C/Faraday 9, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain
| | - Alejandro Martín-González
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, 28049 Cantoblanco, Madrid, Spain
| | - J G Vilhena
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.,Department of Physics, University of Basel, Klingelbergstrasse 82, CH 4056 Basel, Switzerland
| | - Rubén Pérez
- Departamento de Física Teórica de la Materia Condensada, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.,Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, E-28049 Madrid, Spain
| | - Borja Ibarra
- IMDEA Nanociencia, C/Faraday 9, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain.,Instituto Madrileño de Estudios Avanzados en Nanociencia (IMDEA Nanociencia) & CNB-CSIC-IMDEA Nanociencia Associated Unit 'Unidad de Nanobiotecnología', 28049 Madrid, Spain
| | - Clara Aicart-Ramos
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, 28049 Cantoblanco, Madrid, Spain
| | - Fernando Moreno-Herrero
- Department of Macromolecular Structures, Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, 28049 Cantoblanco, Madrid, Spain
| |
Collapse
|