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1.
Arerugi ; 73(3): 268-278, 2024.
Artigo em Japonês | MEDLINE | ID: mdl-38749711

RESUMO

BACKGROUND: In 2022, the "New Capitalism Grand Design and Implementation Plan" was adopted in Japan, emphasizing the promotion and environmental development of startups. Given this context, an investigation into the startup and investment landscape in the allergy sector, both domestically and internationally, becomes imperative. METHODS: We analyzed 156 allergy-related startups from Japan, the US, and Europe from 2010 to 2021. Data on corporate information and investment trends were extracted from databases and VC websites. RESULTS: The total investment reached approximately 7.2 billion USD, with a ratio of 20:6:1 for the US, Europe, and Japan, respectively. The US showed a decline post its peak from 2016-2018, while Europe and Japan experienced growth. Notably, the US primarily invested in biopharmaceuticals for atopic dermatitis and food allergies, Europe in asthma-related apps, and Japan in healthcare apps and cross-border startups. DISCUSSION AND CONCLUSION: While Japan's investment environment in the allergy sector remains in its nascent stages and has room for development, the US and Europe are evidently ahead. Considering the rise of startups and funding limitations in Japan, external funding from regions like the US becomes a potential avenue. These findings are anticipated to contribute to the strategic activation of startups in allergy research and development.


Assuntos
Alergia e Imunologia , Humanos , Alergia e Imunologia/economia , Hipersensibilidade/terapia , Hipersensibilidade/imunologia , Japão , Investimentos em Saúde , Europa (Continente) , Estados Unidos
2.
Nihon Ronen Igakkai Zasshi ; 61(1): 1-12, 2024.
Artigo em Japonês | MEDLINE | ID: mdl-38583963

RESUMO

The epigenome can adequately regulate the on/off states of genes in response to external environmental factors and stress. In recent years, it has been observed that the epigenome, which is modulated through DNA methylation, histone modifications, and chromatin remodeling, changes with age. Alterations in the epigenome lead to the loss of cell-specific epigenome/identity, which in turn triggers a decline in tissue function. In mammals, postnatal epigenomic variations are not only caused by metabolic diseases, such as diabetes or DNA damage, but also by social stress and infectious diseases. Unlike Genome-Wide Association Studies (GWAS), dynamically changing epigenomes, along with their cellular roles, need to be established as objective biomarkers in conjunction with various biological signals, such as walking speed, brain waves, and clinical data. The biological age/aging clock, determined by methylated DNA, has attracted attention, and calorie restriction not only slows the progression of aging, but also seems to suppress it. However, as indicated by gene expression analysis in aging mice, aging is not a linear model, but is represented by nonlinear dynamic changes. Consequently, the development of experimental models and analytical methods that enhance temporal resolution through time-series analysis, tailored to spatial resolution, such as cell distribution and organ specificity, is progressing. Moreover, in recent years, in addition to anti-aging efforts targeting epigenomic variations, global attention has increasingly focused on research and development aimed at rejuvenating treatments, thus leading to the birth of many biotech companies. Aging Hallmarks such as inflammation, stem cells, metabolism, genomic instability, and autophagy, interact closely with the epigenome. Various postnatal and reversible epigenomic controls of aging, including Yamanaka factors (OKSM and OSK), are now entering a new phase. In the future, the development of aging control using diverse modalities, such as mRNA, artificial peptides, and genome editing, is expected, along with an improved molecular understanding of aging and identification of useful biomarkers.


Assuntos
Epigenoma , Histonas , Animais , Camundongos , Histonas/genética , Histonas/metabolismo , Estudo de Associação Genômica Ampla , Biomarcadores , Envelhecimento/genética , Mamíferos/genética , Mamíferos/metabolismo
5.
Life Sci Alliance ; 6(4)2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36750367

RESUMO

The architecture and nuclear location of chromosomes affect chromatin events. Rif1, a crucial regulator of replication timing, recognizes G-quadruplex and inhibits origin firing over the 50-100-kb segment in fission yeast, Schizosaccharomyces pombe, leading us to postulate that Rif1 may generate chromatin higher order structures inhibitory for initiation. However, the effects of Rif1 on chromatin localization in nuclei have not been known. We show here that Rif1 overexpression causes growth inhibition and eventually, cell death in fission yeast. Chromatin-binding activity of Rif1, but not recruitment of phosphatase PP1, is required for growth inhibition. Overexpression of a PP1-binding site mutant of Rif1 does not delay the S-phase, but still causes cell death, indicating that cell death is caused not by S-phase problems but by issues in other phases of the cell cycle, most likely the M-phase. Indeed, Rif1 overexpression generates cells with unequally segregated chromosomes. Rif1 overexpression relocates chromatin near nuclear periphery in a manner dependent on its chromatin-binding ability, and this correlates with growth inhibition. Thus, coordinated progression of S- and M-phases may require regulated Rif1-mediated chromatin association with the nuclear periphery.


Assuntos
Cromatina , Mitose , Proteínas de Schizosaccharomyces pombe , Schizosaccharomyces , Cromatina/genética , Cromatina/metabolismo , Cromossomos/metabolismo , Replicação do DNA , Mitose/genética , Schizosaccharomyces/genética , Proteínas de Schizosaccharomyces pombe/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteínas de Ligação a Telômeros/genética
6.
Cell ; 186(2): 305-326.e27, 2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36638792

RESUMO

All living things experience an increase in entropy, manifested as a loss of genetic and epigenetic information. In yeast, epigenetic information is lost over time due to the relocalization of chromatin-modifying proteins to DNA breaks, causing cells to lose their identity, a hallmark of yeast aging. Using a system called "ICE" (inducible changes to the epigenome), we find that the act of faithful DNA repair advances aging at physiological, cognitive, and molecular levels, including erosion of the epigenetic landscape, cellular exdifferentiation, senescence, and advancement of the DNA methylation clock, which can be reversed by OSK-mediated rejuvenation. These data are consistent with the information theory of aging, which states that a loss of epigenetic information is a reversible cause of aging.


Assuntos
Envelhecimento , Epigênese Genética , Animais , Envelhecimento/genética , Metilação de DNA , Epigenoma , Mamíferos/genética , Nucleoproteínas , Saccharomyces cerevisiae/genética
7.
Sci Rep ; 12(1): 18348, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36319814

RESUMO

We investigated and characterized the prevalence of dry eye disease (DED) in Parkinson's disease (PD). PubMed and EMBASE databases were searched for relevant studies between January 1, 1979 and March 10, 2022. Quality was assessed using the Joanna Briggs Institute Critical Appraisal Checklist. Study-specific estimates were combined using the DerSimonian-Laird random-effects model. Prevalence of subjective DED symptoms in patients with PD and mean differences in blink rate, corneal thickness, tear film breakup time, and tear secretion volume on Schirmer test I were compared to those in controls. Of 383 studies, 13 (1519 patients with PD) and 12 were included in qualitative and quantitative syntheses, respectively. Meta-analysis revealed a 61.1% prevalence of subjective DED symptoms in PD and that, compared with controls, patients with PD had significantly lower blink rate, thinner corneal thickness, shorter tear film breakup time, and lower tear secretion volumes on Schirmer test I, without and with anesthesia.


Assuntos
Síndromes do Olho Seco , Doença de Parkinson , Humanos , Lágrimas , Prevalência , Síndromes do Olho Seco/diagnóstico , Piscadela
8.
Dev Cell ; 56(24): 3309-3320.e5, 2021 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-34932948

RESUMO

Maintaining genomic integrity and stability is crucial for life; yet, no tissue-driven mechanism that robustly safeguards the epithelial genome has been discovered. Epidermal stem cells (EpiSCs) continuously replenish the stratified layers of keratinocytes that protect organisms against various environmental stresses. To study the dynamics of DNA-damaged cells in tissues, we devised an in vivo fate tracing system for EpiSCs with DNA double-strand breaks (DSBs) and demonstrated that those cells exit from their niches. The clearance of EpiSCs with DSBs is caused by selective differentiation and delamination through the DNA damage response (DDR)-p53-Notch/p21 axis, with the downregulation of ITGB1. Moreover, concomitant enhancement of symmetric cell divisions of surrounding stem cells indicates that the selective elimination of cells with DSBs is coupled with the augmented clonal expansion of intact stem cells. These data collectively demonstrate that tissue autonomy through the dynamic coupling of cell-autonomous and non-cell-autonomous mechanisms coordinately maintains the genomic quality of the epidermis.


Assuntos
Epiderme/metabolismo , Genoma , Células-Tronco/citologia , Animais , Apoptose/genética , Diferenciação Celular/genética , Divisão Celular/genética , Proliferação de Células/genética , Células Clonais , Quebras de DNA de Cadeia Dupla , Dano ao DNA/genética , Reparo do DNA/genética , Humanos , Integrina beta1/metabolismo , Camundongos Endogâmicos C57BL , Modelos Biológicos , Receptores Notch/metabolismo , Transdução de Sinais/genética , Nicho de Células-Tronco , Células-Tronco/metabolismo
9.
Brain Nerve ; 73(11): 1201-1207, 2021 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-34759056

RESUMO

Brain function is greatly affected by light, including the daylight hours and light intensity, which are known to have various effects on sleep, cognitive function, and symptoms of depression and Parkinson's disease. On the other hand, light has various colors, such as red and blue, depending on the wavelength, and light receivers also have a diversity of colors, not only to "see" it as visual information but also to "feel" it as a signal of non-visual information. In this section, I would like to introduce the recent findings on the specific regulation of brain functions by the eye, focusing on violet light receptors in the 360-400nm range such as OPN5.


Assuntos
Luz , Fenômenos Fisiológicos do Sistema Nervoso , Encéfalo , Humanos
10.
J Pers Med ; 11(6)2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-34203878

RESUMO

Photobiological neuromodulation and its clinical application has been investigated in recent years. The response of the gamma-oscillation to human visual stimuli is known to be both burst and resonant in nature, and the coupling between alpha and gamma oscillations may play a functional role in visual processing. To date, there is no study that examined the effects of gamma-frequency violet light (VL) stimulation on human electroencephalography (EEG). In this study, we investigated the neurophysiological changes induced by light stimulation using EEG. The purpose of this study was to evaluate the specific effects of 40 Hz gamma-frequency VL stimulation on EEG activity by comparing the effects of white light (WL) with the same condition. Twenty healthy participants (10 females: 37.5 ± 14.3 years; 10 males: 38.0 ± 13.3 years) participated in this study and the following results were observed. First, when compared with the power spectrum density (PSD) of baseline EEG, 40 Hz-WL induced significant increase of PSD in theta band. Second, compared the PSDs between EEG with 40 Hz-VL and EEG with 40 Hz-WL, 40 Hz-VL induced significantly lower enhancement in delta and theta bands than 40 Hz-WL. Third, when focused on the occipital area, negative peak of VEP with 40 Hz-VL was smaller than that of 40 Hz-WL. Fourth, 40 Hz-VL induced an increase of alpha-gamma coupling during the VEP at the F5 electrode site as well as post-EEG at the C4 electrode site, compared with baseline EEG. Thus, the present study suggested that 40 Hz-VL stimulation may induce unique photobiological neuromodulations on human EEG activity.

11.
Sci Rep ; 11(1): 2174, 2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33500490

RESUMO

A decrease in the elasticity of the ocular lens during aging is associated with loss of the accommodative ability of the eye, leading to presbyopia. Although near vision impairment is a social issue affecting the length of healthy life expectancy and productivity of elderly people, an effective treatment to improve near vision has not yet become available. Here we examined the effect of Enterococcus faecium WB2000, Lactobacillus pentosus TJ515, and resveratrol on lens elasticity in rats, where the stiffness of the ocular lens increases exponentially during the aging process. A combination of WB2000 and resveratrol improved lens elasticity not only in the long term but also with just short-term treatment. In addition, TJ515 decreased stiffness in the eye lens with long-term treatment. Therefore, the oral administration of WB2000 and resveratrol or TJ515 may be a potential approach for managing the progression of near vision impairment.


Assuntos
Elasticidade , Lactobacillales/fisiologia , Cristalino/fisiologia , Resveratrol/administração & dosagem , Resveratrol/farmacologia , Administração Oral , Envelhecimento/fisiologia , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Cristalino/efeitos dos fármacos , Masculino , Ratos Wistar
12.
FASEB J ; 34(8): 10778-10800, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32619061

RESUMO

Chronic graft-vs-host disease (cGVHD) is a multifactorial inflammatory disease that affects patients undergoing hematopoietic stem cell transplantation. Multiple organs, including the lacrimal glands (LGs), are negatively affected by cGVHD and lose function due to the resultant fibrosis. An abnormal immune response is thought to be a major factor in the development of chronic ocular GVHD, which is currently treated primarily with immunosuppressive therapies. However, all the treatments yield unsatisfactory outcomes, and additional treatment strategies are needed. To meet this unmet medical need, we aimed to elucidate an additional pathway of chronic ocular GVHD. Our findings suggest a potential association between chronic ocular GVHD pathogenesis and stress-induced cellular senescence through the senescence-associated secretory phenotype (SASP). Senescent cells produce cytokines and chemokines, such as IL-6 and CXCL9. Indeed, senescent cell accumulation was presumably associated with cGVHD development in LGs, as evidenced by the improvement in LGs after the selective elimination of senescent cells (senolysis) with ABT-263. Results in the sclerodermatous cGVHD mouse model suggest that inhibiting the major components of the SASP, including IL-6 and CXCL9, with senolytics is a potential novel strategy for treating cGVHD-affected LGs. Taken together, our results indicate a potential association between the SASP and cGVHD development in LGs and suggest that targeted senolytic treatment may be a new therapeutic option for this disease.


Assuntos
Senescência Celular/fisiologia , Olho/patologia , Doença Enxerto-Hospedeiro/patologia , Animais , Quimiocina CXCL9/metabolismo , Doença Crônica , Citocinas/metabolismo , Modelos Animais de Doenças , Olho/metabolismo , Feminino , Fibrose/metabolismo , Fibrose/patologia , Doença Enxerto-Hospedeiro/metabolismo , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Interleucina-6/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C
13.
Mol Cell Biol ; 37(7)2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28069740

RESUMO

Mrc1 is a conserved checkpoint mediator protein that transduces the replication stress signal to the downstream effector kinase. The loss of mrc1 checkpoint activity results in the aberrant activation of late/dormant origins in the presence of hydroxyurea. Mrc1 was also suggested to regulate orders of early origin firing in a checkpoint-independent manner, but its mechanism was unknown. Here we identify HBS (Hsk1 bypass segment) on Mrc1. An ΔHBS mutant does not activate late/dormant origin firing in the presence of hydroxyurea but causes the precocious and enhanced activation of weak early-firing origins during normal S-phase progression and bypasses the requirement for Hsk1 for growth. This may be caused by the disruption of intramolecular binding between HBS and NTHBS (N-terminal target of HBS). Hsk1 binds to Mrc1 through HBS and phosphorylates a segment adjacent to NTHBS, disrupting the intramolecular interaction. We propose that Mrc1 exerts a "brake" on initiation (through intramolecular interactions) and that this brake can be released (upon the loss of intramolecular interactions) by either the Hsk1-mediated phosphorylation of Mrc1 or the deletion of HBS (or a phosphomimic mutation of putative Hsk1 target serine/threonine), which can bypass the function of Hsk1 for growth. The brake mechanism may explain the checkpoint-independent regulation of early origin firing in fission yeast.


Assuntos
Pontos de Checagem do Ciclo Celular , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Origem de Replicação , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Sequência de Aminoácidos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Hidroxiureia/farmacologia , Modelos Biológicos , Mutação/genética , Peptídeos/farmacologia , Fosforilação/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Origem de Replicação/efeitos dos fármacos , Schizosaccharomyces/efeitos dos fármacos , Schizosaccharomyces/crescimento & desenvolvimento , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/genética , Transdução de Sinais/efeitos dos fármacos
14.
Trends Genet ; 29(8): 449-60, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23809990

RESUMO

Origins of DNA replication on eukaryotic genomes have been observed to fire during S phase in a coordinated manner. Studies in yeast indicate that origin firing is affected by several factors, including checkpoint regulators and chromatin modifiers. However, it is unclear what the mechanisms orchestrating this coordinated process are. Recent studies have identified factors that regulate the timing of origin activation, including Rif1 which plays crucial roles in the regulation of the replication timing program in yeast as well as in higher eukaryotes. In mammalian cells, Rif1 appears to regulate the structures of replication timing domains through its ability to organize chromatin loop structures. Regulation of chromatin architecture by Rif1 may be linked to other chromosome transactions including recombination, repair, or transcription. This review summarizes recent progress in the effort to elucidate the regulatory mechanisms of replication timing of eukaryotic replicons.


Assuntos
Replicação do DNA , Origem de Replicação/genética , Proteínas Repressoras/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Ligação a Telômeros/metabolismo , Animais , Cromatina/genética , Cromossomos/genética , Cromossomos/metabolismo , Humanos , Proteínas Repressoras/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Ligação a Telômeros/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
15.
Genes Dev ; 26(2): 137-50, 2012 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-22279046

RESUMO

One of the long-standing questions in eukaryotic DNA replication is the mechanisms that determine where and when a particular segment of the genome is replicated. Cdc7/Hsk1 is a conserved kinase required for initiation of DNA replication and may affect the site selection and timing of origin firing. We identified rif1Δ, a null mutant of rif1(+), a conserved telomere-binding factor, as an efficient bypass mutant of fission yeast hsk1. Extensive deregulation of dormant origins over a wide range of the chromosomes occurs in rif1Δ in the presence or absence of hydroxyurea (HU). At the same time, many early-firing, efficient origins are suppressed or delayed in firing timing in rif1Δ. Rif1 binds not only to telomeres, but also to many specific locations on the arm segments that only partially overlap with the prereplicative complex assembly sites, although Rif1 tends to bind in the vicinity of the late/dormant origins activated in rif1Δ. The binding to the arm segments occurs through M to G1 phase in a manner independent of Taz1 and appears to be essential for the replication timing program during the normal cell cycle. Our data demonstrate that Rif1 is a critical determinant of the origin activation program on the fission yeast chromosomes.


Assuntos
Período de Replicação do DNA/genética , Origem de Replicação/fisiologia , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Ligação a Telômeros/metabolismo , Proteínas de Ciclo Celular/metabolismo , Sobrevivência Celular/fisiologia , Centrômero/metabolismo , Replicação do DNA/genética , Fase G1 , Deleção de Genes , Ligação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Schizosaccharomyces/crescimento & desenvolvimento , Proteínas de Schizosaccharomyces pombe/genética , Complexo Shelterina , Telômero/metabolismo , Proteínas de Ligação a Telômeros/genética
16.
J Cell Biol ; 195(3): 387-401, 2011 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-22024164

RESUMO

Cdc7/Hsk1 is a conserved kinase required for initiation of DNA replication that potentially regulates timing and locations of replication origin firing. Here, we show that viability of fission yeast hsk1Δ cells can be restored by loss of mrc1, which is required for maintenance of replication fork integrity, by cds1Δ, or by a checkpoint-deficient mutant of mrc1. In these mutants, normally inactive origins are activated in the presence of hydroxyurea and binding of Cdc45 to MCM is stimulated. mrc1Δ bypasses hsk1Δ more efficiently because of its checkpoint-independent inhibitory functions. Unexpectedly, hsk1Δ is viable at 37°C. More DNA is synthesized, and some dormant origins fire in the presence of hydroxyurea at 37°C. Furthermore, hsk1Δ bypass strains grow poorly at 25°C compared with higher temperatures. Our results show that Hsk1 functions for DNA replication can be bypassed by different genetic backgrounds as well as under varied physiological conditions, providing additional evidence for plasticity of the replication program in eukaryotes.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Replicação do DNA , DNA Fúngico/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/enzimologia , Schizosaccharomyces/genética , Transdução de Sinais/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Quinases/genética , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/genética , Origem de Replicação , Schizosaccharomyces/citologia , Proteínas de Schizosaccharomyces pombe/genética , Temperatura
17.
Mol Cell Biol ; 31(12): 2380-91, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21518960

RESUMO

How early- and late-firing origins are selected on eukaryotic chromosomes is largely unknown. Here, we show that Mrc1, a conserved factor required for stabilization of stalled replication forks, selectively binds to the early-firing origins in a manner independent of Cdc45 and Hsk1 kinase in the fission yeast Schizosaccharomyces pombe. In mrc1Δ cells (and in swi1Δ cells to some extent), efficiency of firing is stimulated, and its timing is advanced selectively at those origins that are normally bound by Mrc1. In contrast, the late or inefficient origins which are not bound by Mrc1 are not activated in mrc1Δ cells. The enhanced firing and precocious Cdc45 loading at Mrc1-bound early-firing origins are not observed in a checkpoint mutant of mrc1, suggesting that non-checkpoint function is involved in maintaining the normal program of early-firing origins. We propose that prefiring binding of Mrc1 is an important marker of early-firing origins which are precociously activated by the absence of this protein.


Assuntos
Replicação do DNA , Proteínas de Ligação a DNA/metabolismo , Origem de Replicação/genética , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Cromossomos Fúngicos , DNA Fúngico/genética , DNA Fúngico/metabolismo , Proteínas de Ligação a DNA/genética , Humanos , Componente 4 do Complexo de Manutenção de Minicromossomo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Ligação Proteica , Proteínas de Schizosaccharomyces pombe/genética , Sítio de Iniciação de Transcrição
18.
Cell Cycle ; 9(23): 4627-37, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21099360

RESUMO

In fission yeast, replication fork arrest activates the replication checkpoint effector kinase Cds1(Chk2/Rad53) through the Rad3(ATR/Mec1)-Mrc1(Claspin) pathway. Hsk1, the Cdc7 homologue of fission yeast required for efficient initiation of DNA replication, is also required for Cds1 activation. Hsk1 kinase activity is required for induction and maintenance of Mrc1 hyperphosphorylation, which is induced by replication fork block and mediated by Rad3. Rad3 kinase activity does not change in an hsk1 temperature-sensitive mutant, and Hsk1 kinase activity is not affected by rad3 mutation. Hsk1 kinase vigorously phosphorylates Mrc1 in vitro, predominantly at non-SQ/TQ sites, but this phosphorylation does not seem to affect the Rad3 action on Mrc1. Interestingly, the replication stress-induced activation of Cds1 and hyperphosphorylation of Mrc1 is almost completely abrogated in an initiation-defective mutant of cdc45, but not in an mcm2 or polε mutant. The results suggest that Hsk1-mediated loading of Cdc45 onto replication origins may play important roles in replication stress-induced checkpoint.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/metabolismo , Proteínas de Ciclo Celular/genética , Quinase do Ponto de Checagem 2 , Replicação do DNA , Fosforilação , Proteínas Quinases/metabolismo , Origem de Replicação , Schizosaccharomyces/enzimologia , Proteínas de Schizosaccharomyces pombe/genética , Estresse Fisiológico
19.
J Biol Chem ; 284(35): 23260-71, 2009 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-19556246

RESUMO

Recent studies indicate that the balance between cell survival and proapoptotic signals determines which cells commit to life or death. We have shown that the balance between follicle-stimulating hormone and prolactin determines differentiation or apoptosis in 7th generation spermatogonia during newt spermatogenesis; however, the molecular mechanisms specifying their fate are poorly understood. Here we show that the newt RNA-binding protein (nRBP) plays a critical role in determining their fate. nRBP was identified as a clone whose mRNA is decreased by prolactin, resulting in the reduction of the protein, which is otherwise expressed predominantly in the spermatogonia. nRBP protein associated with the mRNA for newt programmed cell death protein 4 (nPdcd4) at the 3'-untranslated region. nRBP reduction increased nPdcd4 mRNA but decreased its protein. In a cell-free system, cytoplasmic extracts containing reduced amounts of nRBP and nPdcd4 protein induced apoptosis, whereas adding nRBP protein to the extracts blocked apoptosis. Furthermore, overexpression of nRBP protected cells from apoptosis, stabilized the chimeric transcript containing the nPdcd4 3'-untranslated region, and accelerated its translation. These data suggest that, in the absence of nRBP, nPdcd4 mRNA is not stabilized and its translation is suppressed, leading to apoptosis in the spermatogonia.


Assuntos
Proteínas de Anfíbios/genética , Proteínas Reguladoras de Apoptose/genética , Apoptose , Prolactina/metabolismo , Interferência de RNA , Salamandridae/metabolismo , Espermatogônias/metabolismo , Sequência de Aminoácidos , Proteínas de Anfíbios/química , Proteínas de Anfíbios/metabolismo , Animais , Proteínas Reguladoras de Apoptose/química , Proteínas Reguladoras de Apoptose/metabolismo , Feminino , Masculino , Dados de Sequência Molecular , Prolactina/química , Prolactina/genética , Ligação Proteica , Biossíntese de Proteínas , Proteínas de Ligação a RNA/química , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Salamandridae/genética , Alinhamento de Sequência , Espermatogônias/química , Espermatogônias/citologia
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