scholarly journals Genome-wide transcription-coupled repair inEscherichia coliis mediated by the Mfd translocase

2017 ◽  
Vol 114 (11) ◽  
pp. E2116-E2125 ◽  
Author(s):  
Ogun Adebali ◽  
Yi-Ying Chiou ◽  
Jinchuan Hu ◽  
Aziz Sancar ◽  
Christopher P. Selby

We used high-throughput sequencing of short, cyclobutane pyrimidine dimer-containing ssDNA oligos generated during repair of UV-induced damage to study that process at both mechanistic and systemic levels inEscherichia coli. Numerous important insights on DNA repair were obtained, bringing clarity to the respective roles of UvrD helicase and Mfd translocase in repair of UV-induced damage. Mechanistically, experiments showed that the predominant role of UvrD in vivo is to unwind the excised 13-mer from dsDNA and that mutation ofuvrDresults in remarkable protection of that oligo from exonuclease activity as it remains hybridized to the dsDNA. Genome-wide analysis of the transcribed strand/nontranscribed strand (TS/NTS) repair ratio demonstrated that deletion ofmfdglobally shifts the distribution of TS/NTS ratios downward by a factor of about 2 on average for the most highly transcribed genes. Even for the least transcribed genes, Mfd played a role in preferential repair of the transcribed strand. On the other hand, mutation ofuvrD, if anything, slightly pushed the distribution of TS/NTS ratios to higher ratios. These results indicate that Mfd is the transcription repair-coupling factor whereas UvrD plays a role in excision repair by aiding the catalytic turnover of excision repair proteins.

2020 ◽  
Author(s):  
Sruti DebRoy ◽  
Victor Aliaga‐Tobar ◽  
Gabriel Galvez ◽  
Srishtee Arora ◽  
Xiaowen Liang ◽  
...  

2021 ◽  
Vol 22 (2) ◽  
pp. 643
Author(s):  
Xiao Li ◽  
Fen Wang ◽  
Yanyan Xu ◽  
Guijun Liu ◽  
Caihong Dong

Hydrophobins are a family of small secreted proteins found exclusively in fungi, and they play various roles in the life cycle. In the present study, genome wide analysis and transcript profiling of the hydrophobin family in Cordyceps militaris, a well-known edible and medicinal mushroom, were studied. The distribution of hydrophobins in ascomycetes with different lifestyles showed that pathogenic fungi had significantly more hydrophobins than saprotrophic fungi, and class II members accounted for the majority. Phylogenetic analysis of hydrophobin proteins from the species of Cordyceps s.l. indicated that there was more variability among the class II members than class I. Only a few hydrophobin-encoding genes evolved by duplication in Cordyceps s.l., which was inconsistent with the important role of gene duplication in basidiomycetes. Different transcript patterns of four hydrophobin-encoding genes during the life cycle indicated the possible different functions for each. The transcripts of Cmhyd2, 3 and 4 can respond to light and were related with the photoreceptors. CmQHYD, with four hydrophobin II domains, was first found in C. militaris, and multi-domain hydrophobins were only distributed in the species of Cordycipitaceae and Clavicipitaceae. These results could be helpful for further function research of hydrophobins and could provide valuable information for the evolution of hydrophobins.


2013 ◽  
Vol 42 (5) ◽  
pp. 2893-2905 ◽  
Author(s):  
Chunjing Bian ◽  
Xiaochun Yu

Abstract Ten-eleven translocation (TET) family enzymes convert 5-methylcytosine to 5-hydroxylmethylcytosine. However, the molecular mechanism that regulates this biological process is not clear. Here, we show the evidence that PGC7 (also known as Dppa3 or Stella) interacts with TET2 and TET3 both in vitro and in vivo to suppress the enzymatic activity of TET2 and TET3. Moreover, lacking PGC7 induces the loss of DNA methylation at imprinting loci. Genome-wide analysis of PGC7 reveals a consensus DNA motif that is recognized by PGC7. The CpG islands surrounding the PGC7-binding motifs are hypermethylated. Taken together, our study demonstrates a molecular mechanism by which PGC7 protects DNA methylation from TET family enzyme-dependent oxidation.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yong Shi ◽  
Heng Xia ◽  
Xiaoting Cheng ◽  
Libin Zhang

AbstractBackgroundOsmanthus fragransis an important economical plant containing multiple secondary metabolites including flavonoids and anthocyanins. During the past years, the roles of miRNAs in regulating the biosynthesis of secondary metabolites in plants have been widely investigated. However, few studies on miRNA expression profiles and the potential roles in regulating flavonoid biosynthesis have been reported inO. fragrans.ResultsIn this study, we used high-throughput sequencing technology to analyze the expression profiles of miRNAs in leaf and flower tissues ofO. fragrans. As a result, 106 conserved miRNAs distributed in 47 families and 88 novel miRNAs were identified. Further analysis showed there were 133 miRNAs differentially expressed in leaves and flowers. Additionally, the potential target genes of miRNAs as well as the related metabolic pathways were predicted. In the end, flavonoid content was measured in flower and leaf tissues and potential role of miR858 in regulating flavonoid synthesis was illustrated inO. fragrans.ConclusionsThis study not only provided the genome-wide miRNA profiles in the flower and leaf tissue ofO. fragrans, but also investigated the potential regulatory role of miR858a in flavonoid synthesis inO. fragrans. The results specifically indicated the connection of miRNAs to the regulation of secondary metabolite biosynthesis in non-model economical plant.


2021 ◽  
Vol 19 ◽  
Author(s):  
Md. Sahab Uddin ◽  
Md. Tanvir Kabir ◽  
Maroua Jalouli ◽  
Md. Ataur Rahman ◽  
Philippe Jeandet ◽  
...  

: Alzheimer’s disease (AD) is a chronic neurodegenerative disease characterized by the formation of intracellular neurofibrillary tangles (NFTs) and extracellular amyloid plaques. Growing evidence has suggested that AD pathogenesis is not only limited to the neuronal compartment but also strongly interacts with immunological processes in the brain. On the other hand, aggregated and misfolded proteins can bind with pattern recognition receptors located on astroglia and microglia and can in turn induce an innate immune response, characterized by the release of inflammatory mediators, ultimately playing a role in both the severity and the progression of the disease. It has been reported by genome-wide analysis that several genes which elevate the risk for sporadic AD encode for factors controlling the inflammatory response and glial clearance of misfolded proteins. Obesity and systemic inflammation are examples of external factors which may interfere with the immunological mechanisms of the brain and can induce disease progression. In this review, we discussed the mechanisms and essential role of inflammatory signaling pathways in AD pathogenesis. Indeed, interfering with immune processes and modulation of risk factors may lead to future therapeutic or preventive AD approaches.


Sign in / Sign up

Export Citation Format

Share Document