Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Sestrins”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

8 recordsLinked to original sources
PubMed2004

Regeneration of peroxiredoxins by p53-regulated sestrins, homologs of bacterial AhpD.

Acting as a signal, hydrogen peroxide circumvents antioxidant defense by overoxidizing peroxiredoxins (Prxs), the enzymes that metabolize peroxides. We show that sestrins, a family of proteins whose expression is modulated by p53, are required for regeneration of Prxs containing Cys-SO(2)H, thus reestablishing the antioxidant firewall. Sestrins contain a predicted redox-active domain homologous to AhpD, the enzyme catalyzing the reduction of a bacterial Prx, AhpC. Purified Hi95 (sestrin 2) protein supports adenosine triphosphate-dependent reduction of overoxidized PrxI in vitro, indicating that unlike AhpD, which is a disulfide reductase, sestrins are cysteine sulfinyl reductases. As modulators of peroxide signaling and antioxidant defense, sestrins constitute potential therapeutic targets.

Amino Acid Sequence↗
PubMed2003

PA26 is a candidate gene for heterotaxia in humans: identification of a novel PA26-related gene family in human and mouse.

Heterotaxia is an aetiologically heterogeneous condition caused by an abnormal left-right axis formation, resulting in reversed left-right polarity of one or more organ systems. In a patient with heterotaxia and a de novo reciprocal translocation t(6;18)(q21;q21), we found that the PA26 gene was disrupted by the 6q21 breakpoint. Northern blot analysis showed decreased expression of the PA26 gene in an Epstein-Barr virus-transformed cell line of this patient. During early embryogenesis of Xenopus, the orthologue of PA26, XPA26 is exclusively expressed in the notochord, a midline structure. This further supports a possible role of PA26 in human situs determination. Mutation analysis of human PA26 gene in 40 unrelated individuals with unexplained heterotaxia failed to identify mutations, indicating that PA26 mutations are not a frequent cause of heterotaxia in humans. Analysis of the PA26 gene structure resulted in the identification of a novel PA26-related gene family, which we have named the sestrin family, and which comprises three closely related genes in human and in mouse.

Animals↗
PubMed2006

Identifying illness parameters in fatiguing syndromes using classical projection methods.

OBJECTIVES: To examine the potential of multivariate projection methods in identifying common patterns of change in clinical and gene expression data that capture the illness state of subjects with unexplained fatigue and nonfatigued control participants. METHODS: Data for 111 female subjects was examined. A total of 59 indicators, including multidimensional fatigue inventory (MFI), medical outcome Short Form 36 (SF-36), Centers for Disease Control and Prevention (CDC) symptom inventory and cognitive response described illness. Partial least squares (PLS) was used to construct two feature spaces: one describing the symptom space from gene expression in peripheral blood mononuclear cells (PBMC) and one based on 117 clinical variables. Multiplicative scatter correction followed by quantile normalization was applied for trend removal and range adjustment of microarray data. Microarray quality was assessed using mean Pearson correlation between samples. Benjamini-Hochberg multiple testing criteria served to identify significantly expressed probes. RESULTS: A single common trend in 59 symptom constructs isolates of nonfatigued subjects from the overall group. This segregation is supported by two co-regulation patterns representing 10% of the overall microarray variation. Of the 39 principal contributors, the 17 probes annotated related to basic cellular processes involved in cell signaling, ion transport and immune system function. The single most influential gene was sestrin 1 (SESN1), supporting recent evidence of oxidative stress involvement in chronic fatigue syndrome (CFS). Dominant variables in the clinical feature space described heart rate variability (HRV) during sleep. Potassium and free thyroxine (T4) also figure prominently. CONCLUSION: Combining multiple symptom, gene or clinical variables into composite features provides better discrimination of the illness state than even the most influential variable used alone. Although the exact mechanism is unclear, results suggest a common link between oxidative stress, immune system dysfunction and potassium imbalance in CFS patients leading to impaired sympatho-vagal balance strongly reflected in abnormal HRV.

Adult↗
PubMed2001

A Xenopus homolog of a human p53-activated gene, PA26, is specifically expressed in the notochord.

The LIM class homeodomain protein Xlim-1 is specifically expressed in the organizer and later in the notochord in Xenopus. By seeking genes which are activated by Xlim-1 in animal caps, we isolated a gene which encodes a protein highly homologous to human PA26-T2, a p53-inducible nuclear factor, which we refer to as XPA26. Northern blot analysis showed that maternal transcripts of XPA26 are detected at cleavage stages and reduced during gastrulation. Whole-mount in situ hybridization showed that zygotic transcripts of XPA26 were initially detected in the anterior portion of developing notochord at neurula stages, and later in the entire notochord except its posterior region at tailbud stages. Thus the zygotic expression of XPA26 was detected exclusively in the notochord.

Amino Acid Sequence↗
PubMed2003

Identification of amyloid beta-peptide responsive genes by cDNA microarray technology: involvement of RTP801 in amyloid beta-peptide toxicity.

Amyloid beta-peptide (Abeta), a causative molecule in the pathogenesis of Alzheimer's disease and the main component of senile plaques, is known to be neurotoxic in vitro and in vivo. The mechanisms involved in this Ab-mediated neurotoxicity are not fully understood, although there is evidence to suggest the involvement of oxidative stress, alterations in calcium homeostasis, and/or of CDK activators. Many studies have suggested that Ab may exert its toxic effect via the activation of transcription factors. Therefore, we investigated Ab- responsive genes in human neuroblastoma CHP134 cells using 3.1K human DNA microarrays. Among the several genes overexpressed or repressed by Ab, RTP801, Hi95/sestrin 2, and stanniocalcin 2 were confirmed to be Ab-mediated overexpression in the cells by semiquantitative RT-PCR. Transient expression of the sense RTP801 gene in CHP134 cells increased sensitivity to Abeta cytotoxicity and the expression of the antisense RTP801 gene protected the cells from the Abeta toxicity. These results suggest that RTP801 might play important roles in Abeta toxicity and the pathogenesis of Alzheimer's disease.

Alzheimer Disease↗
PubMed1999

PA26, a novel target of the p53 tumor suppressor and member of the GADD family of DNA damage and growth arrest inducible genes.

Exposure of mammalian cells to hypoxia, radiation and certain chemotherapeutic agents promotes cell cycle arrest and/or apoptosis. Activation of p53 responsive genes is believed to play an important role in mediating such responses. In this study we identified a novel gene, PA26, which maps to chromosome 6q21 and encodes at least three transcript isoforms, of which two are differentially induced by genotoxic stress (UV, gamma-irradiation and cytotoxic drugs) in a p53-dependent manner. A functional p53-responsive element was identified in the second intron of the PA26 gene, in consistance with a mechanism of transcriptional induction of the PA26 gene by p53. No clues to its functions were revealed by sequence analysis, although pronounced negative regulation by serum factors argues for a potential role of PA26 in growth regulation. Immunological analysis suggests that PA26 protein(s) is localized to the cell nucleus. Our results suggest that the PA26 gene is a novel p53 target gene with properties common to the GADD family of growth arrest and DNA damage-inducible stress-response genes, and, thus, a potential novel regulator of cellular growth.

Alternative Splicing↗
PubMed2002

Identification of a novel stress-responsive gene Hi95 involved in regulation of cell viability.

cDNA microarray hybridization was used in an attempt to identify novel genes participating in cellular responses to prolonged hypoxia. One of the identified novel genes, designated Hi95 shared significant homology to a p53-regulated GADD family member PA26. In addition to its induction in response to prolonged hypoxia, the increased Hi95 transcription was observed following DNA damage or oxidative stress, but not following hyperthermia or serum starvation. Whereas induction of Hi95 by prolonged hypoxia or by oxidative stress is most likely p53-independent, its induction in response to DNA damaging treatments (gamma- or UV-irradiation, or doxorubicin) occurs in a p53-dependent manner. Overexpression of Hi95 full-length cDNA was found toxic for many types of cultured cells directly leading either to their apoptotic death or to sensitization to serum starvation and DNA damaging treatments. Unexpectedly, conditional overexpression of the Hi95 cDNA in MCF7-tet-off cells resulted in their protection against cell death induced by hypoxia/glucose deprivation or H(2)O(2). Thus, Hi95 gene seems to be involved in complex regulation of cell viability in response to different stress conditions.

Amino Acid Sequence↗
PubMed2006

Sesn1 is a novel gene for left-right asymmetry and mediating nodal signaling.

Remarkable progress has been made in understanding the molecular mechanisms underlying left-right asymmetry in vertebrate animal models but little is known on left-right axis formation in humans. Previously, we identified SESN1 (also known as PA26) as a candidate gene for heterotaxia by positional cloning of the breakpoint regions of a de novo translocation in a heterotaxia patient. In this study, we show by means of a zebrafish sesn1-knockdown model that Sesn1 is required for normal embryonic left-right determination. In this model, developmental defects and expression data of genes implicated in vertebrate left-right asymmetry indicate a role for Sesn1 in mediating Nodal signaling. In the lateral plate mesoderm, Nodal signaling plays a central role in left-right axis formation in vertebrates and is mediated by FoxH1 transcriptional induction. In line with this, we show that Sesn1 physically interacts with FoxH1 or a FoxH1-containing complex. Mutation analysis in a panel of 234 patients with isolated heterotaxia did not reveal mutations, indicating that these are only exceptional causes of human heterotaxia. In this study, we identify SESN1 as an indispensable gene for vertebrate left-right asymmetry and a new player in mediating Nodal signaling.

Animals↗