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The SWI/SNF ATP-Dependent Chromatin Remodeling Complex in Arabidopsis Responds to Environmental Changes in Temperature-Dependent Manner
Get PDFSWI/SNF ATP-dependent chromatin remodeling complexes (CRCs) play important roles in the regulation of transcription, cell cycle, DNA replication, repair, and hormone signaling in eukaryotes. The core of SWI/SNF CRCs composed of a SWI2/SNF2 type ATPase, a SNF5 and two of SWI3 subunits is sufficient for execution of nucleosome remodeling in vitro. The Arabidopsis genome encodes four SWI2/SNF2 ATPases, four SWI3, a single SNF5 and two SWP73 subunits. Genes of the core SWI/SNF components have critical but not fully overlapping roles during plant growth, embryogenesis, and sporophyte development. Here we show that the Arabidopsis swi3c mutant exhibits a phenotypic reversion when grown at lower temperature resulting in partial restoration of its embryo, root development and fertility defects. Our data indicates that the swi3c mutation alters the expression of several genes engaged in low temperature responses. The location of SWI3C-containing SWI/SNF CRCs on the ICE1, MYB15 and CBF1 target genes depends on the temperature conditions, and the swi3c mutation thus also influences the transcription of several cold-responsive (COR) genes. These findings, together with genetic analysis of swi3c/ice1 double mutant and enhanced freezing tolerance of swi3c plants illustrate that SWI/SNF CRCs contribute to fine-tuning of plant growth responses to different temperature regimes
A new potential mode of cardiorenal protection of KLOTHO gene variability in type 1 diabetic adolescents
Get PDFFerritins in Chordata: potential evolutionary trajectory marked by discrete selective pressures
Get PDFFerritins (FTs) are iron storage proteins that are involved in managing iron-oxygen balance. In our work, we present a hypothesis on the putative effect of geological changes that have affected the evolution and radiation of ferritin proteins. Based on sequence analysis and phylogeny reconstruction, we hypothesize that two significant factors have been involved in the evolution of ferritin proteins: fluctuations of atmospheric oxygen concentrations, altering redox potential, and changing availability of water rich in bioavailable ferric ions.
Fish, ancient amphibians, reptiles, and placental mammals developed the broadest repertoire of singular FTs, attributable embryonic growth in aquatic environments containing low oxygen levels and abundant forms of soluble iron. In contrast, oviparous land vertebrates, like reptiles and birds, that have developed in high oxygen levels and limited levels of environmental Fe2+exhibit a lower diversity of singular FTs, but display a broad repertoire of subfamilies, particularly notable in early reptiles
The Peroxisomal Targeting Signal 3 (PTS3) of the Budding Yeast Acyl-CoA Oxidase Is a Signal Patch
Get PDFThe specificity of import of peroxisomal matrix proteins is dependent on the targeting
signals encoded within their amino acid sequences. Two known import signals,
peroxisomal targeting signal 1 (PTS1), positioned at the C-termini and PTS2 located
close to N-termini of these proteins are recognized by the Pex5p and Pex7p receptors,
respectively. However, in several yeast species, including Saccharomyces cerevisiae,
proteins exist that are efficiently imported into peroxisomes despite having neither PTS1
nor PTS2 and for which no other import signal has been determined. An example of such
a protein is S. cerevisiae acyl-CoA oxidase (AOx) encoded by the POX1 gene. While it is
known that its import is driven by its interaction with the N-terminal segment of Pex5p,
which is separate from its C-terminal PTS1-recognizing tetratricopeptide domain, to
date, no AOx polypeptide region has been implicated as critical for this interaction,
and thus would constitute the long-sought PTS3 signal. Using random mutagenesis
combined with a two-hybrid screen, we identified single amino acid residues within the
AOx polypeptide that are crucial for this interaction and for the peroxisomal import of
this protein. Interestingly, while scattered throughout the primary sequence, these amino
acids come close to each other within two domains of the folded AOx. Although the
role of one or both of these regions as the PTS3 signal is not finally proven, our data
indicate that the signal guiding AOx into peroxisomal matrix is not a linear sequence but
a signal patch
Changes in MicroRNA Expression during Rabbit Hemorrhagic Disease Virus (RHDV) Infection.
Get PDFCurrent knowledge on the role of microRNAs (miRNAs) in rabbit hemorrhagic disease
virus (RHDV) infection and the pathogenesis of rabbit hemorrhagic disease (RHD) is still limited.
RHDV replicates in the liver, causing hepatic necrosis and liver failure. MiRNAs are a class of short
RNA molecules, and their expression profiles vary over the course of diseases, both in the tissue
environment and in the bloodstream. This paper evaluates the expression of miRNAs in the liver
tissue (ocu-miR-122-5p, ocu-miR-155-5p, and ocu-miR-16b-5p) and serum (ocu-miR-122-5p) of rabbits
experimentally infected with RHDV. The expression levels of ocu-miR-122-5p, ocu-miR-155-5p,
and ocu-miR-16b-5p in liver tissue were determined using reverse transcription quantitative real-time
PCR (RT-qPCR), and the expression level of circulating ocu-miR-122-5p was established using
droplet digital PCR (ddPCR). The expression levels of ocu-miR-155-5p and ocu-miR-16b-5p were
significantly higher in the infected rabbits compared to the healthy rabbits (a fold-change of 5.8 and 2.5,
respectively). The expression of ocu-miR-122-5p was not significantly di�erent in the liver tissue from
the infected rabbits compared to the healthy rabbits (p = 0.990), while the absolute expression level of
the circulating ocu-miR-122-5p was significantly higher in the infected rabbits than in the healthy
rabbits (p < 0.0001). Furthermore, a functional analysis showed that ocu-miR-155-5p, ocu-miR-16b-5p,
and ocu-miR-122-5p can regulate the expression of genes involved in processes correlated with acute
liver failure (ALF) in rabbits. Search tool for the retrieval of interacting genes/proteins (STRING)
analysis showed that the potential target genes of the three selected miRNAs may interact with
each other in di�erent pathways. The results indicate the roles of these miRNAs in RHDV infection
and over the course of RHD and may reflect hepatic inflammation and impairment/dysfunction
in RHD
Proteasomal Degradation of Proteins is Important for the Proper Transcriptional Response to Sulfur Deficiency Conditions in Plants
Get PDFPlants are continuously exposed to different abiotic and biotic stresses; therefore, to protect themselves they depend on the fast reprogramming of large gene repertoires to prioritize the expression of a given stress-induced gene set over normal cellular household genes. The activity of the proteasome, a large proteolytic complex that degrades proteins, is vital to coordinate the expression of such genes. Proteins are labeled for degradation by the action of E3 ligases that site-specifically alter their substrates by adding chains of ubiquitin. Recent publications have revealed an extensive role of ubiquitination in nutrients utilization. This study presents the transcriptomic profiles of sulfur-deficient rosettes and roots of Arabidopsis thaliana rpt2a mutant with proteasomal malfunction. We found that genes connected with sulfur metabolism are regulated to the lesser extent in rpt2a mutant while genes encoding tRNAs and snoRNAs are highly upregulated. Several genes encoding E3 ligases are specifically regulated by sulfur deficiency. Furthermore, we show that a key transcription factor of sulfur deficiency response, SLIM1, undergoes proteasomal degradation and is able to interact with F-box protein, EBF1
A selective autophagy cargo receptor NBR1 modulates abscisic acid signalling in Arabidopsis thaliana
Get PDFThe plant selective autophagy cargo receptor neighbour of breast cancer 1 gene (NBR1) has been
scarcely studied in the context of abiotic stress. We wanted to expand this knowledge by using
Arabidopsis thaliana lines with constitutive ectopic overexpression of the AtNBR1 gene (OX lines) and
the AtNBR1 Knock-Out (KO lines). Transcriptomic analysis of the shoots and roots of one representative
OX line indicated differences in gene expression relative to the parental (WT) line. In shoots, many
differentially expressed genes, either up- or down-regulated, were involved in responses to stimuli
and stress. In roots the most significant difference was observed in a set of downregulated genes
that is mainly related to translation and formation of ribonucleoprotein complexes. The link between
AtNBR1 overexpression and abscisic acid (ABA) signalling was suggested by an interaction network
analysis of these differentially expressed genes. Most hubs of this network were associated with ABA
signalling. Although transcriptomic analysis suggested enhancement of ABA responses, ABA levels were unchanged in the OX shoots. Moreover, some of the phenotypes of the OX (delayed germination, increased number of closed stomata) and the KO lines (increased number of lateral root initiation sites) indicate that AtNBR1 is essential for fine-tuning of the ABA signalling pathway. The interaction of AtNBR1 with three regulatory proteins of ABA pathway (ABI3, ABI4 and ABI5) was observed in planta. It suggests that AtNBR1 might play role in maintaining the balance of ABA signalling by controlling their level and/or activity
