Evolution of Arabidopsis protection of telomeres 1 alters nucleic acid recognition and telomerase regulation
Protection of telomeres (POT1) binds chromosome ends, recognizing single-strand telomeric DNA via two oligonucleotide/oligosaccharide binding folds (OB-folds). The Arabidopsis thaliana POT1a and POT1b paralogs are atypical: they do not exhibit telomeric DNA binding, and they have opposing roles in regulating telomerase activity. AtPOT1a stimulates repeat addition processivity of the canonical telomerase enzyme, while AtPOT1b interacts with a regulatory lncRNA that represses telomerase activity. Here, we show that OB1 of POT1a, but not POT1b, has an intrinsic affinity for telomeric DNA. DNA binding was dependent upon a high...
Source: Nucleic Acids Research - November 28, 2016 Category: Research Authors: Arora, A., Beilstein, M. A., Shippen, D. E. Tags: Molecular Biology Source Type: research
Human AATF/Che-1 forms a nucleolar protein complex with NGDN and NOL10 required for 40S ribosomal subunit synthesis
Mammalian AATF/Che-1 is essential for embryonic development, however, the underlying molecular mechanism is unclear. By immunoprecipitation of human AATF we discovered that AATF forms a salt-stable protein complex together with neuroguidin (NGDN) and NOL10, and demonstrate that the AATF-NGDN-NOL10 (ANN) complex functions in ribosome biogenesis. All three ANN complex members localize to nucleoli and display a mutual dependence with respect to protein stability. Mapping of protein-protein interaction domains revealed the importance of both the evolutionary conserved WD40 repeats in NOL10 and the UTP3/SAS10 domain in NGDN for...
Source: Nucleic Acids Research - November 28, 2016 Category: Research Authors: Bammert, L., Jonas, S., Ungricht, R., Kutay, U. Tags: Molecular Biology Source Type: research
Exposure to the widely used herbicide atrazine results in deregulation of global tissue-specific RNA transcription in the third generation and is associated with a global decrease of histone trimethylation in mice
In this study, we examine the transgenerational effects promoted by widely used herbicide atrazine (ATZ). We exposed pregnant outbred CD1 female mice and the male progeny was crossed for three generations with untreated females. We demonstrate here that exposure to ATZ affects meiosis, spermiogenesis and reduces the spermatozoa number in the third generation (F3) male mice. We suggest that changes in testis cell types originate from modified transcriptional network in undifferentiated spermatogonia. Importantly, exposure to ATZ dramatically increases the number of transcripts with novel transcription initiation sites, spli...
Source: Nucleic Acids Research - November 28, 2016 Category: Research Authors: Hao, C., Gely-Pernot, A., Kervarrec, C., Boudjema, M., Becker, E., Khil, P., Tevosian, S., Jegou, B., Smagulova, F. Tags: Genomics Source Type: research
Fluorescent sensors of PARP-1 structural dynamics and allosteric regulation in response to DNA damage
Poly(ADP-ribose) (PAR) is a posttranslational modification predominantly synthesized by PAR polymerase-1 (PARP-1) in genome maintenance. PARP-1 detects DNA damage, and damage detection is coupled to a massive increase PAR production, primarily attached to PARP-1 (automodification). Automodified PARP-1 then recruits repair factors to DNA damage sites. PARP-1 automodification eventually leads to release from DNA damage thus turning off catalytic activity, although the effects of PAR on PARP-1 structure are poorly understood. The multiple domains of PARP-1 are organized upon detecting DNA damage, creating a network of domain ...
Source: Nucleic Acids Research - November 28, 2016 Category: Research Authors: Steffen, J. D., McCauley, M. M., Pascal, J. M. Tags: Genome Integrity, Repair and Replication Source Type: research
A programmable Cas9-serine recombinase fusion protein that operates on DNA sequences in mammalian cells
We describe the development of ‘recCas9’, an RNA-programmed small serine recombinase that functions in mammalian cells. We fused a catalytically inactive dCas9 to the catalytic domain of Gin recombinase using an optimized fusion architecture. The resulting recCas9 system recombines DNA sites containing a minimal recombinase core site flanked by guide RNA-specified sequences. We show that these recombinases can operate on DNA sites in mammalian cells identical to genomic loci naturally found in the human genome in a manner that is dependent on the guide RNA sequences. DNA sequencing reveals that recCas9 catalyze...
Source: Nucleic Acids Research - November 28, 2016 Category: Research Authors: Chaikind, B., Bessen, J. L., Thompson, D. B., Hu, J. H., Liu, D. R. Tags: Targeted gene modification Genome integrity, repair and replication Source Type: research
