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Chen Z, Zhao F, He Z, Sun H, Xi Q, Yu X, Ding Y, An Z, Wang J, Liu X, Li M, Hao Z, Li S. Expression Localization of the KRT32 Gene and Its Association of Genetic Variation with Wool Traits. Curr Issues Mol Biol 2024; 46:2961-2974. [PMID: 38666915 PMCID: PMC11049001 DOI: 10.3390/cimb46040185] [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: 01/29/2024] [Revised: 03/02/2024] [Accepted: 03/05/2024] [Indexed: 04/28/2024] Open
Abstract
Changes in keratin gene expression and spatiotemporal regulation determine the compositional content and cellular localization of wool keratin, thereby affecting wool traits. Therefore, keratin gene family member 32 (KRT32) was selected for a study using RT-qPCR, immunofluorescence, and penta-primer amplification refractory mutation system (PARMS) techniques. The results showed that KRT32 mRNA was highly expressed in the skin and localized to the inner root sheath (IRS), outer root sheath (ORS) and dermal papilla (DP). Sequencing results identified eight SNPs in KRT32, and association analyses revealed that the variations were significantly associated with multiple traits in wool (p < 0.05), including MFD, CF and MFC. The constructed haplotype combination H2H3 has higher CF and smaller MFD than other haplotype combination (p < 0.05). In conclusion, KRT32 can be used as a candidate gene for molecular genetic improvement of wool in Gansu Alpine Fine-wool sheep.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Shaobin Li
- Gansu Key Laboratory of Herbivorous Animal Biotechnology, Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; (Z.C.); (F.Z.); (Z.H.); (H.S.); (Q.X.); (X.Y.); (Y.D.); (Z.A.); (J.W.); (X.L.); (M.L.); (Z.H.)
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2
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Chen Z, Cao J, Zhao F, He Z, Sun H, Wang J, Liu X, Li S. Identification of the Keratin-Associated Protein 22-2 Gene in the Capra hircus and Association of Its Variation with Cashmere Traits. Animals (Basel) 2023; 13:2806. [PMID: 37685070 PMCID: PMC10487131 DOI: 10.3390/ani13172806] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/20/2023] [Accepted: 08/31/2023] [Indexed: 09/10/2023] Open
Abstract
The Cashmere goat is an excellent local goat breed in Gansu Province of China, and it is expected to improve cashmere production and cashmere quality through selection and breeding to enhance its commercial value. Keratin-associated proteins (KAPs) play an important role in maintaining wool structure. The gene encoding the keratin-associated protein 22-2 (KAP22-2) gene has been identified in selected species other than goats, such as humans, mice, and sheep. In this study, the sequence of the sheep KAP22-2 gene (KRTAP22-2) was aligned into the goat genome, and the sequence with the highest homology was assumed to be the goat KRTAP22-2 sequence and used to design primers to amplify the goat gene sequence. A total of 356 Longdong Cashmere goats (Gansu Province, China) were used for screening of genetic variants. Four specific bands were detected by polymerase chain reaction-single-stranded conformational polymorphism (PCR-SSCP) analysis, and they formed a total of six band types individually or in combination. Four alleles were identified by DNA sequencing of PCR amplification products. A total of four single nucleotide polymorphic sites (SNPs) were detected in the four sequenced KRTAP22-2 alleles. Two of them are in the 5'UTR region and the other two are in the coding region, and the variants in the coding region are all non-synonymous mutations. In addition, there was a 6 bp length variation in allele C. The gene was expressed in the cortical layer of primary and secondary hair follicles, the inner root sheath, as well as hair papillae and hair maternal cells in goats. The results of the correlation analysis between genotypes and cashmere traits showed that after excluding genotypes with a gene frequency of less than 5%, the mean fiber diameter (MFD) of cashmere was significantly higher in the AB genotype than in the AA and AC genotypes. That is, the KRTAP22-2 gene variants are associated with mean fiber diameter in cashmere. The above results suggest that the goat KRTAP22-2 variant can be utilized as a molecular marker candidate gene for cashmere traits.
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Affiliation(s)
- Zhanzhao Chen
- Gansu Key Laboratory of Herbivorous Animal Biotechnology, Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; (Z.C.); (F.Z.); (Z.H.); (H.S.); (J.W.); (X.L.)
| | - Jian Cao
- Faculty of Bioengineering, Jiuquan Vocational Technical College, Jiuquan 735000, China;
| | - Fangfang Zhao
- Gansu Key Laboratory of Herbivorous Animal Biotechnology, Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; (Z.C.); (F.Z.); (Z.H.); (H.S.); (J.W.); (X.L.)
| | - Zhaohua He
- Gansu Key Laboratory of Herbivorous Animal Biotechnology, Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; (Z.C.); (F.Z.); (Z.H.); (H.S.); (J.W.); (X.L.)
| | - Hongxian Sun
- Gansu Key Laboratory of Herbivorous Animal Biotechnology, Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; (Z.C.); (F.Z.); (Z.H.); (H.S.); (J.W.); (X.L.)
| | - Jiqing Wang
- Gansu Key Laboratory of Herbivorous Animal Biotechnology, Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; (Z.C.); (F.Z.); (Z.H.); (H.S.); (J.W.); (X.L.)
| | - Xiu Liu
- Gansu Key Laboratory of Herbivorous Animal Biotechnology, Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; (Z.C.); (F.Z.); (Z.H.); (H.S.); (J.W.); (X.L.)
| | - Shaobin Li
- Gansu Key Laboratory of Herbivorous Animal Biotechnology, Faculty of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; (Z.C.); (F.Z.); (Z.H.); (H.S.); (J.W.); (X.L.)
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3
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Wright SE, Todd PK. Native functions of short tandem repeats. eLife 2023; 12:e84043. [PMID: 36940239 PMCID: PMC10027321 DOI: 10.7554/elife.84043] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 03/08/2023] [Indexed: 03/21/2023] Open
Abstract
Over a third of the human genome is comprised of repetitive sequences, including more than a million short tandem repeats (STRs). While studies of the pathologic consequences of repeat expansions that cause syndromic human diseases are extensive, the potential native functions of STRs are often ignored. Here, we summarize a growing body of research into the normal biological functions for repetitive elements across the genome, with a particular focus on the roles of STRs in regulating gene expression. We propose reconceptualizing the pathogenic consequences of repeat expansions as aberrancies in normal gene regulation. From this altered viewpoint, we predict that future work will reveal broader roles for STRs in neuronal function and as risk alleles for more common human neurological diseases.
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Affiliation(s)
- Shannon E Wright
- Department of Neurology, University of Michigan–Ann ArborAnn ArborUnited States
- Neuroscience Graduate Program, University of Michigan–Ann ArborAnn ArborUnited States
- Department of Neuroscience, Picower InstituteCambridgeUnited States
| | - Peter K Todd
- Department of Neurology, University of Michigan–Ann ArborAnn ArborUnited States
- VA Ann Arbor Healthcare SystemAnn ArborUnited States
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Bukhari SAS, Razzaq A, Jabeen J, Khan S, Khan Z. Deep-BSC: Predicting Raw DNA Binding Pattern in Arabidopsis Thaliana. Curr Bioinform 2021. [DOI: 10.2174/1574893615999200707142852] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
With the rapid development of the sequencing methods in recent years,
binding sites have been systematically identified in such projects as Nested-MICA and MEME.
Prediction of DNA motifs with higher accuracy and precision has been a very important task for
bioinformaticians. Nevertheless, experimental approaches are still time-consuming for big data set,
making computational identification of binding sites indispensable.
Objective:
To facilitate the identification of the binding site, we proposed a deep learning architecture, named Deep-BSC
(Deep-Learning Binary Search Classification), to predict binding sites in a raw DNA sequence with more precision and
accuracy.
Methods:
Our proposed architecture purely relies on the raw DNA sequence to predict the binding
sites for protein by using a convolutional neural network (CNN). We trained our deep learning
model on binding sites at the nucleotide level. DNA sequence of A. thaliana is used in this study
because it is a model plant.
Results:
The results demonstrate the effectiveness and efficiency of our method in the classification
of binding sites against random sequences, using deep learning. We construct a CNN with different
layers and filters to show the usefulness of max-pooling technique in the proposed method. To gain
the interpretability of our approach, we further visualized binding sites in the saliency map and
successfully identified similar motifs in the raw sequence. The proposed computational framework
is time and resource efficient.
Conclusion:
Deep-BSC enables the identification of binding sites in the DNA sequences via a highly accurate CNN. The
proposed computational framework can also be applied to problems such as operator, repeats in the genome, DNA
markers, and recognition sites for enzymes, thereby promoting the use of Deep-BSC method in life sciences.
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Affiliation(s)
- Syed Adnan Shah Bukhari
- Department of Computer Science, Faculty of Social Science and Humanities, Muhammad Nawaz Sharif University of Agriculture, Multan, Pakistan
| | - Abdul Razzaq
- Department of Computer Science, Faculty of Social Science and Humanities, Muhammad Nawaz Sharif University of Agriculture, Multan, Pakistan
| | - Javeria Jabeen
- Department of Computer Science, Faculty of Social Science and Humanities, Muhammad Nawaz Sharif University of Agriculture, Multan, Pakistan
| | - Shaheer Khan
- Department of Computer Science, Faculty of Social Science and Humanities, Muhammad Nawaz Sharif University of Agriculture, Multan, Pakistan
| | - Zulqurnain Khan
- Department of Biotechnology, Institute of Plant Breeding and Biotechnology, Muhammad Nawaz Sharif University of Agriculture, Multan, Pakistan
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Algama M, Oldmeadow C, Tasker E, Mengersen K, Keith JM. Drosophila 3' UTRs are more complex than protein-coding sequences. PLoS One 2014; 9:e97336. [PMID: 24824035 PMCID: PMC4019593 DOI: 10.1371/journal.pone.0097336] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 04/18/2014] [Indexed: 01/03/2023] Open
Abstract
The 3′ UTRs of eukaryotic genes participate in a variety of post-transcriptional (and some transcriptional) regulatory interactions. Some of these interactions are well characterised, but an undetermined number remain to be discovered. While some regulatory sequences in 3′ UTRs may be conserved over long evolutionary time scales, others may have only ephemeral functional significance as regulatory profiles respond to changing selective pressures. Here we propose a sensitive segmentation methodology for investigating patterns of composition and conservation in 3′ UTRs based on comparison of closely related species. We describe encodings of pairwise and three-way alignments integrating information about conservation, GC content and transition/transversion ratios and apply the method to three closely related Drosophila species: D. melanogaster, D. simulans and D. yakuba. Incorporating multiple data types greatly increased the number of segment classes identified compared to similar methods based on conservation or GC content alone. We propose that the number of segments and number of types of segment identified by the method can be used as proxies for functional complexity. Our main finding is that the number of segments and segment classes identified in 3′ UTRs is greater than in the same length of protein-coding sequence, suggesting greater functional complexity in 3′ UTRs. There is thus a need for sustained and extensive efforts by bioinformaticians to delineate functional elements in this important genomic fraction. C code, data and results are available upon request.
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Affiliation(s)
- Manjula Algama
- School of Mathematical Sciences, Monash University, Clayton, Victoria, Australia
| | - Christopher Oldmeadow
- School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
| | - Edward Tasker
- School of Mathematical Sciences, Monash University, Clayton, Victoria, Australia
| | - Kerrie Mengersen
- School of Mathematical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Jonathan M. Keith
- School of Mathematical Sciences, Monash University, Clayton, Victoria, Australia
- * E-mail:
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6
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Abstract
Several studies have shown that synthesis of new proteins at the synapse is a prerequisite for the storage of long-term memories. Relatively little is known about the availability of distinct mRNA populations for translation at specific synapses, the process that determines mRNA localization, and the temporal designations of localized mRNA translation during memory storage. Techniques such as synaptosome preparation and microdissection of distal neuronal processes of cultured neurons and dendritic layers in brain slices are general approaches used to identify localized RNAs. Exploration of the association of RNA-binding proteins to the axonal transport machinery has led to the development of a strategy to identify RNAs that are transported from the cell body to synapses by molecular motor kinesin. In this article, RNA localization at the synapse, as well as its mechanisms and significance in understanding long-term memory storage, are discussed.
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7
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Dassi E, Quattrone A. Tuning the engine: an introduction to resources on post-transcriptional regulation of gene expression. RNA Biol 2012; 9:1224-32. [PMID: 22995832 DOI: 10.4161/rna.22035] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
In the last years post-transcriptional regulation (PTR) of gene expression has been increasingly recognized to be a powerful and general determinant of the quantitative changes in proteomes, and therefore a driving force for cell phenotypes. By means of networks of trans-factors on one hand, and cis-elements found primarily in untranslated regions (UTRs) of mRNA on the other hand, mRNA availability to translation and translation rates are tightly controlled and can be rapidly tuned according to the changing state of the cell. A number of dedicated resources and tools, including databases and predictive algorithms, have been proposed as bioinformatics aids for the study of this fundamental layer of gene expression regulation. Their use, however, is rendered difficult by heterogeneity and fragmentation. This review aims to locate these resources in their proper space, classifying them according to their goals, limitations and integration capabilities and, in the end, to provide the user with an initial toolbox for the bioinformatic analysis of post-transcriptional regulation of gene expression. The accompanying website, available at www.ptrguide.org, lists all resources, provides summary and features for each one and will be regularly updated in the future.
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Affiliation(s)
- Erik Dassi
- Laboratory of Translational Genomics, Centre for Integrative Biology, University of Trento, Trento, Italy
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8
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Liang R, Wang E. Full-length 3'-untranslated region reporter construction with recombineering. Anal Biochem 2012; 424:162-7. [PMID: 22366478 DOI: 10.1016/j.ab.2012.01.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Revised: 01/11/2012] [Accepted: 01/13/2012] [Indexed: 11/25/2022]
Abstract
Complexity in higher animals derives in part from various modalities of protein-coding gene expression regulation, including microRNA repression by binding to 3'-untranslated regions (UTRs) of specific genes. Reporter constructs containing candidate microRNA target sites are a popular approach of functional studies, and full-length 3'-UTR sequences are preferred because they contain all regulatory elements and preserve higher order structure as much as possible. However, this approach is often handicapped by the extreme length of the 3'-UTR. Here, we present a rapid and accurate cloning procedure to generate full-length 3'-UTR reporter constructs by recombinogenic engineering (recombineering) in vivo cloning. The approach includes making retrieval constructs by sequence- and ligation-independent cloning (SLIC) and retrieving the full-length 3'-UTR in one exon to the retrieval construct from a bacterial artificial chromosome (BAC) by recombineering to generate the final full-length 3'-UTR reporter construct for the gene of interest. This method is successfully implemented with mouse full-length 3'-UTRs of Igf1 (6.5 kb), Igf1r (7.5 kb), and Sp1 (5.5 kb). Expansion of this method is adaptable to retrieve 3'-UTRs encoded in more than one exon by removing the introns from the BAC first with recombineering. This method will advance functional studies of regulation of gene expression at the post-transcriptional level through microRNA suppression.
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Affiliation(s)
- Ruqiang Liang
- Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY 40202, USA
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9
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Abstract
Axon regeneration is a fundamental problem facing neuroscientists and clinicians. Failure of axon regeneration is caused by both extrinsic and intrinsic mechanisms. New techniques to examine gene expression such as Next Generation Sequencing of the Transcriptome (RNA-Seq) drastically increase our knowledge of both gene expression complexity (RNA isoforms) and gene expression regulation. By utilizing RNA-Seq, gene expression can now be defined at the level of isoforms, an essential step for understanding the mechanisms governing cell identity, growth and ultimately cellular responses to injury and disease.
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Affiliation(s)
- Jessica K Lerch
- The Miami Project to Cure Paralysis, The University of Miami, Miami, FL, USA
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10
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Vollmeister E, Feldbrügge M. Posttranscriptional control of growth and development in Ustilago maydis. Curr Opin Microbiol 2010; 13:693-9. [DOI: 10.1016/j.mib.2010.08.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Accepted: 08/31/2010] [Indexed: 11/16/2022]
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11
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Cuykendall TN, Houston DW. Identification of germ plasm-associated transcripts by microarray analysis of Xenopus vegetal cortex RNA. Dev Dyn 2010; 239:1838-48. [PMID: 20503379 DOI: 10.1002/dvdy.22304] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
RNA localization is a common mechanism for regulating cell structure and function. Localized RNAs in Xenopus oocytes are critical for early development, including germline specification by the germ plasm. Despite the importance of these localized RNAs, only approximately 25 have been identified and fewer are functionally characterized. Using microarrays, we identified a large set of localized RNAs from the vegetal cortex. Overall, our results indicate a minimum of 275 localized RNAs in oocytes, or 2-3% of maternal transcripts, which are in general agreement with previous findings. We further validated vegetal localization for 24 candidates and further characterized three genes expressed in the germ plasm. We identified novel germ plasm expression for reticulon 3.1, exd2 (a novel exonuclease-domain encoding gene), and a putative noncoding RNA. Further analysis of these and other localized RNAs will likely identify new functions of germ plasm and facilitate the identification of cis-acting RNA localization elements.
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Affiliation(s)
- Tawny N Cuykendall
- The University of Iowa, Department of Biology, Iowa City, Iowa 52242-1324, USA
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12
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Shumay E, Fowler JS, Volkow ND. Genomic features of the human dopamine transporter gene and its potential epigenetic States: implications for phenotypic diversity. PLoS One 2010; 5:e11067. [PMID: 20548783 PMCID: PMC2883569 DOI: 10.1371/journal.pone.0011067] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Accepted: 05/18/2010] [Indexed: 02/06/2023] Open
Abstract
Human dopamine transporter gene (DAT1 or SLC6A3) has been associated with various brain-related diseases and behavioral traits and, as such, has been investigated intensely in experimental- and clinical-settings. However, the abundance of research data has not clarified the biological mechanism of DAT regulation; similarly, studies of DAT genotype-phenotype associations yielded inconsistent results. Hence, our understanding of the control of the DAT protein product is incomplete; having this knowledge is critical, since DAT plays the major role in the brain's dopaminergic circuitry. Accordingly, we reevaluated the genomic attributes of the SLC6A3 gene that might confer sensitivity to regulation, hypothesizing that its unique genomic characteristics might facilitate highly dynamic, region-specific DAT expression, so enabling multiple regulatory modes. Our comprehensive bioinformatic analyzes revealed very distinctive genomic characteristics of the SLC6A3, including high inter-individual variability of its sequence (897 SNPs, about 90 repeats and several CNVs spell out all abbreviations in abstract) and pronounced sensitivity to regulation by epigenetic mechanisms, as evident from the GC-bias composition (0.55) of the SLC6A3, and numerous intragenic CpG islands (27 CGIs). We propose that this unique combination of the genomic features and the regulatory attributes enables the differential expression of the DAT1 gene and fulfills seemingly contradictory demands to its regulation; that is, robustness of region-specific expression and functional dynamics.
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Affiliation(s)
- Elena Shumay
- Brookhaven National Laboratory, Medical Department, Upton, New York, United States of America
- * E-mail: (ES); (JSF); (NDV)
| | - Joanna S. Fowler
- Brookhaven National Laboratory, Medical Department, Upton, New York, United States of America
- * E-mail: (ES); (JSF); (NDV)
| | - Nora D. Volkow
- National Institute on Drug Abuse, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail: (ES); (JSF); (NDV)
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Abstract
The localization and local translation of mRNAs constitute an important mechanism to promote the correct subcellular targeting of proteins. mRNA localization is mediated by the active transport of mRNPs, large assemblies consisting of mRNAs and associated factors such as RNA-binding proteins. Molecular motors move mRNPs along the actin or microtubule cytoskeleton for short-distance or long-distance trafficking, respectively. In filamentous fungi, microtubule-based long-distance transport of vesicles, which are involved in membrane and cell wall expansion, supports efficient hyphal growth. Recently, we discovered that the microtubule-mediated transport of mRNAs is essential for the fast polar growth of infectious filaments in the corn pathogen Ustilago maydis. Combining in vivo UV cross-linking and RNA live imaging revealed that the RNA-binding protein Rrm4, which constitutes an integral part of the mRNP transport machinery, mediates the transport of distinct mRNAs encoding polarity factors, protein synthesis factors, and mitochondrial proteins. Moreover, our results indicate that microtubule-dependent mRNA transport is evolutionarily conserved from fungi to higher eukaryotes. This raises the exciting possibility of U. maydis as a model system to uncover basic concepts of long-distance mRNA transport.
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Catania F, Lynch M. Evolutionary dynamics of a conserved sequence motif in the ribosomal genes of the ciliate Paramecium. BMC Evol Biol 2010; 10:129. [PMID: 20441586 PMCID: PMC2874801 DOI: 10.1186/1471-2148-10-129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2009] [Accepted: 05/04/2010] [Indexed: 01/08/2023] Open
Abstract
Background In protozoa, the identification of preserved motifs by comparative genomics is often impeded by difficulties to generate reliable alignments for non-coding sequences. Moreover, the evolutionary dynamics of regulatory elements in 3' untranslated regions (both in protozoa and metazoa) remains a virtually unexplored issue. Results By screening Paramecium tetraurelia's 3' untranslated regions for 8-mers that were previously found to be preserved in mammalian 3' UTRs, we detect and characterize a motif that is distinctly conserved in the ribosomal genes of this ciliate. The motif appears to be conserved across Paramecium aurelia species but is absent from the ribosomal genes of four additional non-Paramecium species surveyed, including another ciliate, Tetrahymena thermophila. Motif-free ribosomal genes retain fewer paralogs in the genome and appear to be lost more rapidly relative to motif-containing genes. Features associated with the discovered preserved motif are consistent with this 8-mer playing a role in post-transcriptional regulation. Conclusions Our observations 1) shed light on the evolution of a putative regulatory motif across large phylogenetic distances; 2) are expected to facilitate the understanding of the modulation of ribosomal genes expression in Paramecium; and 3) reveal a largely unexplored--and presumably not restricted to Paramecium--association between the presence/absence of a DNA motif and the evolutionary fate of its host genes.
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Affiliation(s)
- Francesco Catania
- Department of Biology, Indiana University, 1001E 3rd Street, Bloomington, IN 47405, USA.
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15
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Paix A, Yamada L, Dru P, Lecordier H, Pruliere G, Chenevert J, Satoh N, Sardet C. Cortical anchorages and cell type segregations of maternal postplasmic/PEM RNAs in ascidians. Dev Biol 2009; 336:96-111. [DOI: 10.1016/j.ydbio.2009.09.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2009] [Revised: 08/18/2009] [Accepted: 09/01/2009] [Indexed: 11/16/2022]
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16
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Triplet repeat length bias and variation in the human transcriptome. Proc Natl Acad Sci U S A 2009; 106:17095-100. [PMID: 19805156 DOI: 10.1073/pnas.0907112106] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Length variation in short tandem repeats (STRs) is an important family of DNA polymorphisms with numerous applications in genetics, medicine, forensics, and evolutionary analysis. Several major diseases have been associated with length variation of trinucleotide (triplet) repeats including Huntington's disease, hereditary ataxias and spinobulbar muscular atrophy. Using the reference human genome, we have catalogued all triplet repeats in genic regions. This data revealed a bias in noncoding DNA repeat lengths. It also enabled a survey of repeat-length polymorphisms (RLPs) in human genomes and a comparison of the rate of polymorphism in humans versus divergence from chimpanzee. For short repeats, this analysis of three human genomes reveals a relatively low RLP rate in exons and, somewhat surprisingly, in introns. All short RLPs observed in multiple genomes are biallelic (at least in this small sample). In contrast, long repeats are highly polymorphic and some long RLPs are multiallelic. For long repeats, the chimpanzee sequence frequently differs from all observed human alleles. This suggests a high expansion/contraction rate in all long repeats. Expansions and contractions are not, however, affected by natural selection discernable from our comparison of human-chimpanzee divergence with human RLPs. Our catalog of human triplet repeats and their surrounding flanking regions can be used to produce a cost-effective whole-genome assay to test individuals. This repeat assay could someday complement SNP arrays for producing tests that assess the risk of an individual to develop a disease, or become part of personalized genomic strategy that provides therapeutic guidance with respect to drug response.
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König J, Baumann S, Koepke J, Pohlmann T, Zarnack K, Feldbrügge M. The fungal RNA-binding protein Rrm4 mediates long-distance transport of ubi1 and rho3 mRNAs. EMBO J 2009; 28:1855-66. [PMID: 19494833 DOI: 10.1038/emboj.2009.145] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Accepted: 05/08/2009] [Indexed: 11/09/2022] Open
Abstract
Cytoskeletal transport promotes polar growth in filamentous fungi. In Ustilago maydis, the RNA-binding protein Rrm4 shuttles along microtubules and is crucial for polarity in infectious filaments. Mutations in the RNA-binding domain cause loss of function. However, it was unclear which RNAs are bound and transported. Here, we applied in vivo RNA binding studies and live imaging to determine the molecular function of Rrm4. This new combination revealed that Rrm4 mediates microtubule-dependent transport of distinct mRNAs encoding, for example, the ubiquitin fusion protein Ubi1 and the small G protein Rho3. These transcripts accumulate in ribonucleoprotein particles (mRNPs) that move bidirectionally along microtubules and co-localise with Rrm4. Importantly, the 3' untranslated region of ubi1 containing a CA-rich binding site functions as zipcode during mRNA transport. Furthermore, motile mRNPs are not formed when the RNA-binding domain of Rrm4 is deleted, although the protein is still shuttling. Thus, Rrm4 constitutes an integral component of the transport machinery. We propose that microtubule-dependent mRNP trafficking is crucial for hyphal growth introducing U. maydis as attractive model for studying mRNA transport in higher eukaryotes.
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Affiliation(s)
- Julian König
- Department of Organismic Interactions, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
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Heinrich B, Deshler JO. RNA localization to the Balbiani body in Xenopus oocytes is regulated by the energy state of the cell and is facilitated by kinesin II. RNA (NEW YORK, N.Y.) 2009; 15:524-536. [PMID: 19223445 PMCID: PMC2661827 DOI: 10.1261/rna.975309] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2007] [Accepted: 12/03/2008] [Indexed: 05/27/2023]
Abstract
Xenopus oocytes provide an excellent model system for understanding the cis-elements and protein factors that carry out mRNA localization in vertebrate cells. More than 20 mRNAs have been identified that localize to the vegetal cortex during stages II-IV of oogenesis. The earliest localizing RNAs are presorted to a subcellular structure, the Balbiani body (also called the mitochondrial cloud in Xenopus), of stage I oocytes prior to entering the vegetal cortex. While some evidence has suggested that diffusion drives RNA localization to the Balbiani body, a role for temperature and metabolic energy in this process has not been explored. To address this issue, we developed a quantitative assay to monitor RNA localization in stage I oocytes. Here we show that the rate of RNA accumulation to the Balbiani body is highly dependent on temperature and the intracellular concentration of ATP. In fact, while ATP depletion severely impairs RNA localization, increasing the intracellular concentration of ATP by a factor of two doubles the localization rate, indicating that ATP is limiting under normal conditions. We also show that RNA localization in stage I oocytes is reduced by inhibition of kinesin II, and that the Xcat-2 RNA localization element recruits kinesin II to the Balbiani body. We conclude from these studies that the energy state of the cell regulates the rate of RNA localization to the Balbiani body and that this process, at least to some extent, involves kinesin II.
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Affiliation(s)
- Bianca Heinrich
- Department of Biology, Boston University, Massachusetts 02215, USA
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