scholarly journals Dosage-sensitivity of human transcription factor genes

2019 ◽  
Author(s):  
Zhihua Ni ◽  
Xiao-Yu Zhou ◽  
Sidra Aslam ◽  
Deng-Ke Niu

AbstractChanges in the copy number of protein-coding genes would lead to detrimental effects if the consequent changes in protein concentration disrupt essential cellular functions. Large-scale genomic studies have identified thousands of dosage-sensitive genes in human genome. We are interested in the dosage-sensitivity of transcription factor (TF) genes whose products are essential for the growth, division and differentiation of cells by regulating the expression of the genetic information encoded in the genome. We first surveyed the enrichment of human TF genes in four recently curated datasets of dosage-sensitive genes, including the haploinsufficient genes identified by a large-scale genomic study, the haploinsufficient genes predicted by a machine learning approach, the genes with conserved copy number across mammals, and the ohnologs. Then we selected the dosage-sensitive genes that are present in all the four dataset and regarded them as the most reliable dosage-sensitive genes, and the genes that are absent from any one of the four datasets as the most reliable dosage-insensitive genes, and surveyed the enrichments of TFs genes in these two datasets. A large number of TF genes were found to be dosage-insensitive, which is beyond the expectation based on the role of TFs. In spite of this, the likeness of TF genes to be dosage-sensitive were supported by five datasets, with the conserved-copy-number genes as the exception. The nuclear receptors are the only one family of TFs whose dosage-sensitivity was consistently supported by all the six datasets. In addition, we found that TF families with very few members are also more likely to be dosage-sensitive while the largest TF family, C2H2-ZF, are most likely dosage-insensitive. The most extensively studied TFs, p53, are not special in dosage-sensitivity. They are significantly enriched in only three datasets. We also confirmed that dosage-sensitive genes generally have long coding sequences, high expression levels and experienced stronger selective pressure. Our results indicate some TFs function in a dose-dependent manner while some other not. Gene dosage changes in some TF families like nuclear receptor would result in disease phenotypes while the effects of such changes in some TFs like C2H2-ZF would be mild.

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0254447
Author(s):  
Marcos Francia ◽  
Martin Stortz ◽  
Camila Vazquez Echegaray ◽  
Camila Oses ◽  
Paula Verneri ◽  
...  

Akt/PKB is a kinase involved in the regulation of a wide variety of cell processes. Its activity is modulated by diverse post-translational modifications (PTMs). Particularly, conjugation of the small ubiquitin-related modifier (SUMO) to this kinase impacts on multiple cellular functions, such as proliferation and splicing. In embryonic stem (ES) cells, this kinase is key for pluripotency maintenance. Among other functions, Akt is known to promote the expression of Nanog, a central pluripotency transcription factor (TF). However, the relevance of this specific PTM of Akt has not been previously analyzed in this context. In this work, we study the effect of Akt1 variants with differential SUMOylation susceptibility on the expression of Nanog. Our results demonstrate that both, the Akt1 capability of being modified by SUMO conjugation and a functional SUMO conjugase activity are required to induce Nanog gene expression. Likewise, we found that the common oncogenic E17K Akt1 mutant affected Nanog expression in ES cells also in a SUMOylatability dependent manner. Interestingly, this outcome takes places in ES cells but not in a non-pluripotent heterologous system, suggesting the presence of a crucial factor for this induction in ES cells. Remarkably, the two major candidate factors to mediate this induction, GSK3-β and Tbx3, are non-essential players of this effect, suggesting a complex mechanism probably involving non-canonical pathways. Furthermore, we found that Akt1 subcellular distribution does not depend on its SUMOylatability, indicating that Akt localization has no influence on the effect on Nanog, and that besides the membrane localization of E17K Akt mutant, SUMOylation is also required for its hyperactivity. Our results highlight the impact of SUMO conjugation in the function of a kinase relevant for a plethora of cellular processes, including the control of a key pluripotency TF.


2016 ◽  
Vol 113 (31) ◽  
pp. 8855-8860 ◽  
Author(s):  
Geoffrey Benn ◽  
Marta Bjornson ◽  
Haiyan Ke ◽  
Amancio De Souza ◽  
Edward I. Balmond ◽  
...  

The general stress response (GSR) is an evolutionarily conserved rapid and transient transcriptional reprograming of genes central for transducing environmental signals into cellular responses, leading to metabolic and physiological readjustments to cope with prevailing conditions. Defining the regulatory components of the GSR will provide crucial insight into the design principles of early stress-response modules and their role in orchestrating master regulators of adaptive responses. Overaccumulation of methylerythritol cyclodiphosphate (MEcPP), a bifunctional chemical entity serving as both a precursor of isoprenoids produced by the plastidial methylerythritol phosphate (MEP) pathway and a stress-specific retrograde signal, in ceh1 (constitutively expressing hydroperoxide lyase1)-mutant plants leads to large-scale transcriptional alterations. Bioinformatic analyses of microarray data in ceh1 plants established the overrepresentation of a stress-responsive cis element and key GSR marker, the rapid stress response element (RSRE), in the promoters of robustly induced genes. ceh1 plants carrying an established 4×RSRE:Luciferase reporter for monitoring the GSR support constitutive activation of the response in this mutant background. Genetics and pharmacological approaches confirmed the specificity of MEcPP in RSRE induction via the transcription factor CALMODULIN-BINDING TRANSCRIPTION ACTIVATOR 3 (CAMTA3), in a calcium-dependent manner. Moreover, CAMTA3-dependent activation of IRE1a (inositol-requiring protein-1) and bZIP60 (basic leucine zipper 60), two RSRE containing unfolded protein-response genes, bridges MEcPP-mediated GSR induction to the potentiation of protein-folding homeostasis in the endoplasmic reticulum. These findings introduce the notion of transcriptional regulation by a key plastidial retrograde signaling metabolite that induces nuclear GSR, thereby offering a window into the role of interorgannellar communication in shaping cellular adaptive responses.


2021 ◽  
Author(s):  
Yutaro Hori ◽  
Akira Shimamoto ◽  
Takehiko Kobayashi

The structure of the human ribosomal DNA (rDNA) cluster has traditionally been hard to analyze owing to its highly repetitive nature. However, the recent development of long-read sequencing technology, such as Oxford Nanopore sequencing, has enabled us to study the large-scale structure of the genome. Using this technology, we found that human cells have a quite regular rDNA structure. Although each human rDNA copy has some variations in its noncoding region, contiguous copies of rDNA are similar, suggesting that homogenization through gene conversion frequently occurs between copies. Analysis of rDNA methylation by Nanopore sequencing further showed that all the noncoding regions are heavily methylated, whereas about half of the coding regions are clearly unmethylated. The ratio of unmethylated copies, which are speculated to be transcriptionally active, was lower in individuals with a higher rDNA copy number, suggesting that there is a mechanism that keeps the active copy number stable. In addition, the rDNA in progeroid syndrome patient cells with reduced DNA repair activity had more unstable copies compared with control normal cells, although the rate was much lower than previously reported using a fiber-FISH method. Collectively, our results clarify the view of rDNA stability and transcription regulation in human cells, indicating the presence of mechanisms for both homogenizations to ensure sequence quality and maintenance of active copies for cellular functions.


2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Yulia Rybakova ◽  
John T. Gonzalez ◽  
Roman Bogorad ◽  
Vikash P. Chauhan ◽  
Yize L. Dong ◽  
...  

AbstractGenomic studies have significantly improved our understanding of hepatocellular carcinoma (HCC) biology and have led to the discovery of multiple protein-coding genes driving hepatocarcinogenesis. In addition, these studies have identified thousands of new non-coding transcripts deregulated in HCC. We hypothesize that some of these transcripts may be involved in disease progression. Long non-coding RNAs are a large class of non-coding transcripts which participate in the regulation of virtually all cellular functions. However, a majority of lncRNAs remain dramatically understudied. Here, we applied a pooled shRNA-based screen to identify lncRNAs essential for HCC cell survival. We validated our screening results using RNAi, CRISPRi, and antisense oligonucleotides. We found a lncRNA, termed ASTILCS, that is critical for HCC cell growth and is overexpressed in tumors from HCC patients. We demonstrated that HCC cell death upon ASTILCS knockdown is associated with apoptosis induction and downregulation of a neighboring gene, protein tyrosine kinase 2 (PTK2), a crucial protein for HCC cell survival. Taken together, our study describes a new, non-coding RNA regulator of HCC.


2001 ◽  
Vol 21 (2) ◽  
pp. 614-623 ◽  
Author(s):  
Angel Hernández-Hernández ◽  
Alberto Ferrús

ABSTRACT The transcription factor TFIID is a multiprotein complex that includes the TATA box binding protein (TBP) and a number of associated factors, TAFII. Prodos (PDS) is a conserved protein that exhibits a histone fold domain (HFD). In yeast two-hybrid tests using PDS as bait, we cloned the Drosophila TAFII, dTAFII16, as a specific PDS target. dTAFII16 is closely related to human TAFII30 and to another recently discovered Drosophila TAF, dTAFII24. PDS and dTAFII24 do not interact, however, thus establishing a functional difference between these dTAFs. The PDS-dTAFII16 interaction is mediated by the HFD motif in PDS and the N terminus in dTAFII16, as indicated by yeast two-hybrid assays with protein fragments. Luciferase-reported transcription tests in transfected cells show that PDS or an HFD-containing fragment activates transcription only with the help of dTAFII16 and TBP. Consistent with this, the eye phenotype of flies expressing asev-Ras1 construct is modulated by PDS and dTAFII16 in a gene dosage-dependent manner. Finally, we show that PDS function is required for cell viability in somatic mosaics. These findings indicate that PDS is a novel transcriptional coactivator that associates with a member of the general transcription factor TFIID.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ramon Viñas ◽  
Tiago Azevedo ◽  
Eric R. Gamazon ◽  
Pietro Liò

A question of fundamental biological significance is to what extent the expression of a subset of genes can be used to recover the full transcriptome, with important implications for biological discovery and clinical application. To address this challenge, we propose two novel deep learning methods, PMI and GAIN-GTEx, for gene expression imputation. In order to increase the applicability of our approach, we leverage data from GTEx v8, a reference resource that has generated a comprehensive collection of transcriptomes from a diverse set of human tissues. We show that our approaches compare favorably to several standard and state-of-the-art imputation methods in terms of predictive performance and runtime in two case studies and two imputation scenarios. In comparison conducted on the protein-coding genes, PMI attains the highest performance in inductive imputation whereas GAIN-GTEx outperforms the other methods in in-place imputation. Furthermore, our results indicate strong generalization on RNA-Seq data from 3 cancer types across varying levels of missingness. Our work can facilitate a cost-effective integration of large-scale RNA biorepositories into genomic studies of disease, with high applicability across diverse tissue types.


2008 ◽  
Vol 06 (06) ◽  
pp. 1157-1175 ◽  
Author(s):  
DOMINIC ROSE ◽  
JULIAN JÖRIS ◽  
JÖRG HACKERMÜLLER ◽  
KRISTIN REICHE ◽  
QIANG LI ◽  
...  

Teleost fishes share a duplication of their entire genomes. We report here on a computational survey of structured non-coding RNAs (ncRNAs) in teleost genomes, focusing on the fate of fish-specific duplicates. As in other metazoan groups, we find evidence of a large number (11,543) of structured RNAs, most of which (~86%) are clade-specific or evolve so fast that their tetrapod homologs cannot be detected. In surprising contrast to protein-coding genes, the fish-specific genome duplication did not lead to a large number of paralogous ncRNAs: only 188 candidates, mostly microRNAs, appear in a larger copy number in teleosts than in tetrapods, suggesting that large-scale gene duplications do not play a major role in the expansion of the vertebrate ncRNA inventory.


2020 ◽  
Author(s):  
Yulia Rybakova ◽  
John T. Gonzalez ◽  
Roman Bogorad ◽  
Vikash P. Chauhan ◽  
Yize L. Dong ◽  
...  

ABSTRACTGenomic studies have significantly improved our understanding of hepatocellular carcinoma (HCC) biology and have led to the discovery of multiple protein-coding genes driving hepatocarcinogenesis. In addition, these studies have identified thousands of new non-coding transcripts deregulated in HCC. We hypothesize that some of these transcripts may be involved in disease progression. Long non-coding RNAs are a large class of non-coding transcripts which participate in the regulation of virtually all cellular functions. However, a majority of lncRNAs remain dramatically understudied. Here, we applied a pooled shRNA-based screen to identify lncRNAs essential for HCC cell survival. We validated our screening results using RNAi, CRISPRi, and antisense oligonucleotides. We found a lncRNA, termed ASTILCS, that is critical for HCC cell growth and is overexpressed in tumors from HCC patients. We demonstrated that HCC cell death upon ASTILCS knockdown is associated with apoptosis induction and downregulation of a neighboring gene, Protein Tyrosine Kinase 2 (PTK2), a crucial protein for HCC cell survival. Taken together, our study describes a new, non-coding RNA regulator of HCC.


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