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1.
Plant Cell ; 35(9): 3345-3362, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37335899

RESUMO

Plants cope with various recurring stress conditions that often induce DNA damage, ultimately affecting plant genome integrity, growth, and productivity. The CROWDED NUCLEI (CRWN) family comprises lamin-like proteins with multiple functions, such as regulating gene expression, genome organization, and DNA damage repair in Arabidopsis (Arabidopsis thaliana). However, the mechanisms and consequences of CRWNs in DNA damage repair are largely unknown. Here, we reveal that CRWNs maintain genome stability by forming repairing nuclear bodies at DNA double-strand breaks. We demonstrate that CRWN1 and CRWN2 physically associate with the DNA damage repair proteins RAD51D and SUPPRESSOR OF NPR1-1 Inducible 1 (SNI1) and act in the same genetic pathway to mediate this process. Moreover, CRWN1 and CRWN2 partially localize at γ-H2AX foci upon DNA damage. Notably, CRWN1 and CRWN2 undergo liquid-liquid phase separation to form highly dynamic droplet-like structures with RAD51D and SNI1 to promote the DNA damage response (DDR). Collectively, our data shed light on the function of plant lamin-like proteins in the DDR and maintenance of genome stability.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Laminas/metabolismo , Proteínas Nucleares/metabolismo , Dano ao DNA/genética , Reparo do DNA/genética , Instabilidade Genômica , Proteínas Repressoras/metabolismo
2.
J Biol Chem ; 300(1): 105534, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38072050

RESUMO

Significant advances have been made in reprogramming various somatic cells into induced pluripotent stem cells (iPSCs) and in multi-lineage differentiation (transdifferentiation) into different tissues. These manipulable transdifferentiating techniques may be applied in cancer therapy. Limited works have been reported that cancer cell malignancy can be switched to benign phenotypes through reprogramming techniques. Here, we reported that two colorectal cancer (CRC) cell lines (DLD1, HT29) could be reprogrammed into iPSCs (D-iPSCs, H-iPSCs). D- and H-iPSCs showed reduced tumorigenesis. Furthermore, we successfully induced D- and H-iPSCs differentiation into terminally differentiated cell types such as cardiomyocyte, neuron, and adipocyte-like cells. Impressively, the differentiated cells exhibited further attenuated tumorigenesis in vitro and in vivo. RNA-Seq further indicated that epigenetic changes occurred after reprogramming and transdifferentiation that caused reduced tumorigenicity. Overall, our study indicated that CRC cells can be reprogrammed and further differentiated into terminally differentiated lineages with attenuation of their malignancy in vitro and in vivo. The current work sheds light on a potential multi-lineage differentiation therapeutic strategy for colorectal cancer.


Assuntos
Carcinogênese , Transdiferenciação Celular , Técnicas de Reprogramação Celular , Neoplasias Colorretais , Células-Tronco Pluripotentes Induzidas , Humanos , Carcinogênese/patologia , Diferenciação Celular/genética , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia
3.
Biochem Biophys Res Commun ; 724: 150233, 2024 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-38865814

RESUMO

Cryptochromes (CRYs) are blue light (BL) photoreceptors to regulate a variety of physiological processes including DNA double-strand break (DSB) repair. SUPPRESSOR OF GAMMA RADIATION 1 (SOG1) acts as the central transcription factor of DNA damage response (DDR) to induce the transcription of downstream genes, including DSB repair-related genes BRCA1 and RAD51. Whether CRYs regulate DSB repair by directly modulating SOG1 is unknown. Here, we demonstrate that CRYs physically interact with SOG1. Disruption of CRYs and SOG1 leads to increased sensitivity to DSBs and reduced DSB repair-related genes' expression under BL. Moreover, we found that CRY1 enhances SOG1's transcription activation of DSB repair-related gene BRCA1. These results suggest that the mechanism by which CRYs promote DSB repair involves positive regulation of SOG1's transcription of its target genes, which is likely mediated by CRYs-SOG1 interaction.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Criptocromos , Quebras de DNA de Cadeia Dupla , Reparo do DNA , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/metabolismo , Criptocromos/metabolismo , Criptocromos/genética , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética
4.
Biochem Biophys Res Commun ; 717: 150050, 2024 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-38718571

RESUMO

Cryptochromes (CRYs) act as blue light photoreceptors to regulate various plant physiological processes including photomorphogenesis and repair of DNA double strand breaks (DSBs). ADA2b is a conserved transcription co-activator that is involved in multiple plant developmental processes. It is known that ADA2b interacts with CRYs to mediate blue light-promoted DSBs repair. Whether ADA2b may participate in CRYs-mediated photomorphogenesis is unknown. Here we show that ADA2b acts to inhibit hypocotyl elongation and hypocotyl cell elongation in blue light. We found that the SWIRM domain-containing C-terminus mediates the blue light-dependent interaction of ADA2b with CRYs in blue light. Moreover, ADA2b and CRYs act to co-regulate the expression of hypocotyl elongation-related genes in blue light. Based on previous studies and these results, we propose that ADA2b plays dual functions in blue light-mediated DNA damage repair and photomorphogenesis.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Regulação da Expressão Gênica de Plantas , Hipocótilo , Luz , Arabidopsis/genética , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/efeitos da radiação , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/metabolismo , Hipocótilo/efeitos da radiação , Hipocótilo/genética , Criptocromos/metabolismo , Criptocromos/genética , Reparo do DNA/efeitos da radiação , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Morfogênese/efeitos da radiação , Luz Azul
5.
Plant Cell Environ ; 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39253954

RESUMO

Stomata are epidermal openings that facilitate plant-atmosphere gas and water exchange during photosynthesis, respiration and water evaporation. SPEECHLESS (SPCH) is a master basic helix-loop-helix (bHLH) transcription factor that determines the initiation of stomatal development. It is known that blue light promotes stomatal development through the blue light photoreceptor cryptochromes (CRYs, CRY1 and CRY2). Whether CRYs regulate stomatal development through directly modulating SPCH is unknown. Here, we demonstrate by biochemical studies that CRY1 physically interacts with SPCH in a blue light-dependent manner. Genetic studies show that SPCH acts downstream of CRY1 to promote stomatal development in blue light. Furthermore, we show that CRY1 enhances the DNA-binding activity of SPCH and promotes the expression of its target genes in blue light. These results suggest that the mechanism by which CRY1 promotes stomatal development involves positive regulation of the DNA-binding activity of SPCH, which is likely mediated by blue light-induced CRY1-SPCH interaction. The precise regulation of SPCH DNA-binding activity by CRY1 may allow plants to optimize stomatal density and pattern according to ambient light conditions.

6.
Microb Pathog ; 192: 106668, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38697232

RESUMO

OBJECTIVES: The emergence of carbapenem-resistant Pseudomonas putida (CRPP) has raised public awareness. This study investigated two strains from the Pseudomonas putida group that were resistant to carbapenem, tigecycline, and aztreonam-avibactam (ATM-AVI), with a focus on their microbial and genomic characteristics. METHODS: We assessed the antibiotic resistance profile using broth dilution, disk diffusion, and E-test methods. Efflux pump phenotype testing and real-time quantitative PCR were employed to evaluate efflux pump activity in tigecycline resistance, while polymerase chain reaction was utilized to detect common carbapenem genes. Additionally, whole-genome sequencing was performed to analyze genomic characteristics. The transferability of blaIMP-1 and blaAFM-4 was assessed through a conjugation experiment. Furthermore, growth kinetics and biofilm formation were examined using growth curves and crystal violet staining. RESULTS: Both strains demonstrated resistance to carbapenem, tigecycline, and ATM-AVI. Notably, NMP can restore sensitivity to tigecycline. Subsequent analysis revealed that they co-produced blaIMP-1, blaAFM-4, tmexCD-toprJ, and blaOXA-1041, belonging to a novel sequence type ST268. Although they were closely related on the phylogenetic tree, they exhibited different levels of virulence. Genetic environment analysis indicated variations compared to prior studies, particularly regarding the blaIMP-1 and blaAFM-4 genes, which showed limited horizontal transferability. Moreover, it was observed that temperature exerted a specific influence on their biological factors. CONCLUSION: We initially identified two P. putida ST268 strains co-producing blaIMP-1, blaAFM-4, blaOXA-1041, and tmexCD-toprJ. The resistance to tigecycline and ATM-AVI can be attributed to the presence of multiple drug resistance determinants. These findings underscore the significance of P. putida as a reservoir for novel antibiotic resistance genes. Therefore, it is imperative to develop alternative antibiotic therapies and establish effective monitoring of bacterial resistance.


Assuntos
Antibacterianos , Compostos Azabicíclicos , Aztreonam , Testes de Sensibilidade Microbiana , Pseudomonas putida , Tigeciclina , beta-Lactamases , Pseudomonas putida/genética , Pseudomonas putida/efeitos dos fármacos , Tigeciclina/farmacologia , Antibacterianos/farmacologia , China , Aztreonam/farmacologia , Compostos Azabicíclicos/farmacologia , beta-Lactamases/genética , beta-Lactamases/metabolismo , Farmacorresistência Bacteriana Múltipla/genética , Sequenciamento Completo do Genoma , Humanos , Combinação de Medicamentos , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Infecções por Pseudomonas/microbiologia , Carbapenêmicos/farmacologia
7.
Plant Cell ; 33(7): 2375-2394, 2021 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-34046684

RESUMO

Cryptochromes are blue light photoreceptors that mediate various light responses in plants and mammals. In Arabidopsis (Arabidopsis thaliana), cryptochrome 1 (CRY1) mediates blue light-induced photomorphogenesis, which is characterized by reduced hypocotyl elongation and enhanced anthocyanin production, whereas gibberellin (GA) signaling mediated by the GA receptor GA-INSENSITIVE DWARF1 (GID1) and DELLA proteins promotes hypocotyl elongation and inhibits anthocyanin accumulation. Whether CRY1 control of photomorphogenesis involves regulation of GA signaling is largely unknown. Here, we show that CRY1 signaling involves the inhibition of GA signaling through repression of GA-induced degradation of DELLA proteins. CRY1 physically interacts with DELLA proteins in a blue light-dependent manner, leading to their dissociation from SLEEPY1 (SLY1) and the inhibition of their ubiquitination. Moreover, CRY1 interacts directly with GID1 in a blue light-dependent but GA-independent manner, leading to the inhibition of the interaction between GID1 with DELLA proteins. These findings suggest that CRY1 controls photomorphogenesis through inhibition of GA-induced degradation of DELLA proteins and GA signaling, which is mediated by CRY1 inhibition of the interactions of DELLA proteins with GID1 and SCFSLY1, respectively.


Assuntos
Proteínas de Arabidopsis/metabolismo , Luz , Receptores de Superfície Celular/metabolismo , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas/fisiologia , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Giberelinas/metabolismo , Receptores de Superfície Celular/genética , Transdução de Sinais/fisiologia , Transdução de Sinais/efeitos da radiação
8.
Plant Cell ; 33(6): 1961-1979, 2021 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-33768238

RESUMO

Light is a key environmental cue that fundamentally regulates plant growth and development, which is mediated by the multiple photoreceptors including the blue light (BL) photoreceptor cryptochrome 1 (CRY1). The signaling mechanism of Arabidopsis thaliana CRY1 involves direct interactions with CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1)/SUPPRESSOR OF PHYA-105 1 and stabilization of COP1 substrate ELONGATED HYPOCOTYL 5 (HY5). H2A.Z is an evolutionarily conserved histone variant, which plays a critical role in transcriptional regulation through its deposition in chromatin catalyzed by SWR1 complex. Here we show that CRY1 physically interacts with SWC6 and ARP6, the SWR1 complex core subunits that are essential for mediating H2A.Z deposition, in a BL-dependent manner, and that BL-activated CRY1 enhances the interaction of SWC6 with ARP6. Moreover, HY5 physically interacts with SWC6 and ARP6 to direct the recruitment of SWR1 complex to HY5 target loci. Based on previous studies and our findings, we propose that CRY1 promotes H2A.Z deposition to regulate HY5 target gene expression and photomorphogenesis in BL through the enhancement of both SWR1 complex activity and HY5 recruitment of SWR1 complex to HY5 target loci, which is likely mediated by interactions of CRY1 with SWC6 and ARP6, and CRY1 stabilization of HY5, respectively.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiologia , Proteínas Cromossômicas não Histona/metabolismo , Criptocromos/metabolismo , Histonas/metabolismo , Arabidopsis/citologia , Proteínas de Arabidopsis/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Clorofila/biossíntese , Clorofila/metabolismo , Proteínas Cromossômicas não Histona/genética , Criptocromos/genética , Regulação da Expressão Gênica de Plantas , Histonas/genética , Hipocótilo/crescimento & desenvolvimento , Hipocótilo/metabolismo , Luz , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Fitocromo A/genética , Fitocromo A/metabolismo , Fitocromo B/genética , Fitocromo B/metabolismo , Plantas Geneticamente Modificadas , Mapas de Interação de Proteínas , Nicotiana/genética , Nicotiana/metabolismo
9.
New Phytol ; 234(4): 1347-1362, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34449898

RESUMO

Arabidopsis cryptochrome 1 (CRY1) is an important blue light photoreceptor that promotes photomorphogenesis under blue light. The blue light photoreceptors CRY2 and phototropin 1, and the red/far-red light photoreceptors phytochromes B and A undergo degradation in response to blue and red light, respectively. This study investigated whether and how CRY1 might undergo degradation in response to high-intensity blue light (HBL). We demonstrated that CRY1 is ubiquitinated and degraded through the 26S proteasome pathway in response to HBL. We found that the E3 ubiquitin ligase constitutive photomorphogenic 1 (COP1) is involved in mediating HBL-induced ubiquitination and degradation of CRY1. We also found that the E3 ubiquitin ligases LRBs physically interact with CRY1 and are also involved in mediating CRY1 ubiquitination and degradation in response to HBL. We further demonstrated that blue-light inhibitor of cryptochromes 1 interacts with CRY1 in a blue-light-dependent manner to inhibit CRY1 dimerization/oligomerization, leading to the repression of HBL-induced degradation of CRY1. Our findings indicate that the regulation of CRY1 stability in HBL is coordinated by COP1 and LRBs, which provides a mechanism by which CRY1 attenuates its own signaling and optimizes photomorphogenesis under HBL.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Criptocromos/metabolismo , Regulação da Expressão Gênica de Plantas , Luz , Fatores de Transcrição/metabolismo , Ubiquitina-Proteína Ligases/metabolismo
10.
Plant Physiol ; 184(1): 487-505, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32661061

RESUMO

Cryptochromes are photolyase-like, blue-light (BL) photoreceptors found in various organisms. Arabidopsis (Arabidopsis thaliana) cryptochromes (CRYs; CRY1, and CRY2) mediate many light responses including photoperiodic floral initiation. Cryptochromes interact with COP1 and SPA1, causing the stabilization of CONSTANS (CO) and promotion of FLOWERING LOCUS T (FT) transcription and flowering. The AP2-like transcriptional factor TOE1 negatively regulates FT expression and flowering by indirectly inhibiting CO transcriptional activation activity and directly binding to FT Here, we demonstrate that CRY1 and CRY2 physically interact with TOE1 and TOE2 in a BL-dependent manner in flowering regulation. Genetic studies showed that mutation of TOE1 and TOE2 partially suppresses the late-flowering phenotype of cry1 cry2 mutant plants. BL-triggered interactions of CRY2 with TOE1 and TOE2 promote the dissociation of TOE1 and TOE2 from CO, resulting in alleviation of their inhibition of CO transcriptional activity and enhanced transcription of FT Furthermore, we show that CRY2 represses TOE1 binding to the regulatory element within the Block E enhancer of FT These results reveal that TOE1 and TOE2 act as downstream components of CRY2, thus partially mediating CRY2 regulation of photoperiodic flowering through modulation of CO activity and FT transcription.


Assuntos
Arabidopsis/metabolismo , Criptocromos/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Criptocromos/genética , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
11.
Plant Cell ; 30(9): 1989-2005, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30131420

RESUMO

Cryptochromes (CRYs) are blue light photoreceptors that mediate a variety of light responses in plants and animals, including photomorphogenesis, flowering, and circadian rhythms. The signaling mechanism by which Arabidopsis thaliana cryptochromes CRY1 and CRY2 promote photomorphogenesis involves direct interactions with COP1, a RING motif-containing E3 ubiquitin ligase, and its enhancer SPA1. Brassinosteroid (BR) is a key phytohormone involved in the repression of photomorphogenesis, and here, we show that the signaling mechanism of Arabidopsis CRY1 involves the inhibition of BR signaling. CRY1 and CRY2 physically interact with BES1-INTERACTING MYC-LIKE1 (BIM1), a basic helix-loop-helix protein. BIM1, in turn, interacts with and enhances the activity of BRI1-EMS SUPPRESSOR1 (BES1), a master transcription factor in the BR signaling pathway. In addition, CRY1 and CRY2 interact specifically with dephosphorylated BES1, the physiologically active form of BES1 that is activated by BR in a blue light-dependent manner. The CRY1-BES1 interaction leads to both the inhibition of BES1 DNA binding activity and the repression of its target gene expression. Our study suggests that the blue light-dependent, BR-induced interaction of CRY1 with BES1 is a tightly regulated mechanism by which plants optimize photomorphogenesis according to the availability of external light and internal BR signals.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Brassinosteroides/metabolismo , Criptocromos/metabolismo , Luz , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Criptocromos/genética , Regulação da Expressão Gênica de Plantas/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Fosforilação/efeitos da radiação , Transdução de Sinais/genética , Transdução de Sinais/efeitos da radiação
12.
PLoS Genet ; 14(3): e1007247, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29522510

RESUMO

Light and microRNAs (miRNAs) are key external and internal signals for plant development, respectively. However, the relationship between the light signaling and miRNA biogenesis pathways remains unknown. Here we found that miRNA processer proteins DCL1 and HYL1 interact with a basic helix-loop-helix (bHLH) transcription factor, phytochrome-interacting factor 4 (PIF4), which mediates the destabilization of DCL1 during dark-to-red-light transition. PIF4 acts as a transcription factor for some miRNA genes and is necessary for the proper accumulation of miRNAs. DCL1, HYL1, and mature miRNAs play roles in the regulation of plant hypocotyl growth. These results uncovered a previously unknown crosstalk between miRNA biogenesis and red light signaling through the PIF4-dependent regulation of miRNA transcription and processing to affect red-light-directed plant photomorphogenesis.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Ciclo Celular/metabolismo , MicroRNAs/metabolismo , Ribonuclease III/metabolismo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Proteínas de Ciclo Celular/genética , Regulação da Expressão Gênica de Plantas , Hipocótilo/genética , Hipocótilo/crescimento & desenvolvimento , Luz , MicroRNAs/genética , Plantas Geneticamente Modificadas , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Ribonuclease III/genética , Transdução de Sinais/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
13.
J Integr Plant Biol ; 63(6): 1133-1146, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33982818

RESUMO

Light serves as a crucial environmental cue which modulates plant growth and development, and which is controlled by multiple photoreceptors including the primary red light photoreceptor, phytochrome B (phyB). The signaling mechanism of phyB involves direct interactions with a group of basic helix-loop-helix (bHLH) transcription factors, PHYTOCHROME-INTERACTING FACTORS (PIFs), and the negative regulators of photomorphogenesis, COP1 and SPAs. H2A.Z is an evolutionarily conserved H2A variant which plays essential roles in transcriptional regulation. The replacement of H2A with H2A.Z is catalyzed by the SWR1 complex. Here, we show that the Pfr form of phyB physically interacts with the SWR1 complex subunits SWC6 and ARP6. phyB and ARP6 co-regulate numerous genes in the same direction, some of which are associated with auxin biosynthesis and response including YUC9, which encodes a rate-limiting enzyme in the tryptophan-dependent auxin biosynthesis pathway. Moreover, phyB and HY5/HYH act to inhibit hypocotyl elongation partially through repression of auxin biosynthesis. Based on our findings and previous studies, we propose that phyB promotes H2A.Z deposition at YUC9 to inhibit its expression through direct phyB-SWC6/ARP6 interactions, leading to repression of auxin biosynthesis, and thus inhibition of hypocotyl elongation in red light.


Assuntos
Proteínas de Arabidopsis/isolamento & purificação , Arabidopsis/metabolismo , Luz , Fitocromo B/metabolismo , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica de Plantas , Hipocótilo/metabolismo , Hipocótilo/efeitos da radiação
14.
J Integr Plant Biol ; 63(11): 1967-1981, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34469075

RESUMO

Cryptochromes are blue light photoreceptors that mediate various light responses in plants and mammals. The heterotrimeric G-protein is known to regulate various physiological processes in plants and mammals. In Arabidopsis, cryptochrome 1 (CRY1) and the G-protein ß subunit AGB1 act antagonistically to regulate stomatal development. The molecular mechanism by which CRY1 and AGB1 regulate this process remains unknown. Here, we show that Arabidopsis CRY1 acts partially through AGB1, and AGB1 acts through SPEECHLESS (SPCH), a master transcription factor that drives stomatal initiation and proliferation, to regulate stomatal development. We demonstrate that AGB1 physically interacts with SPCH to block the bHLH DNA-binding domain of SPCH and inhibit its DNA-binding activity. Moreover, we demonstrate that photoexcited CRY1 represses the interaction of AGB1 with SPCH to release AGB1 inhibition of SPCH DNA-binding activity, leading to the expression of SPCH-target genes promoting stomatal development. Taken together, our results suggest that the mechanism by which CRY1 promotes stomatal development involves positive regulation of the DNA-binding activity of SPCH mediated by CRY1 inhibition of the AGB1-SPCH interaction. We propose that the antagonistic regulation of SPCH DNA-binding activity by CRY1 and AGB1 may allow plants to balance light and G-protein signaling and optimize stomatal density and pattern.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Criptocromos/metabolismo , Subunidades beta da Proteína de Ligação ao GTP/metabolismo , Estômatos de Plantas/crescimento & desenvolvimento , Arabidopsis/crescimento & desenvolvimento , Arabidopsis/efeitos da radiação , Regulação da Expressão Gênica de Plantas
15.
New Phytol ; 225(2): 848-865, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514232

RESUMO

Arabidopsis CRY1 and phyB are the primary blue and red light photoreceptors mediating blue and red light inhibition of hypocotyl elongation, respectively. Auxin is a pivotal phytohormone involved in promoting hypocotyl elongation. CRY1 and phyB interact with and stabilize auxin/indole acetic acid proteins (Aux/IAAs) to inhibit auxin signaling. The present study investigated whether photoreceptors might interact directly with Auxin Response Factors (ARFs) to regulate auxin signaling. Protein-protein interaction studies demonstrated that CRY1 and phyB interact physically with ARF6 and ARF8 through their N-terminal domains in a blue and red light-dependent manner, respectively. Moreover, the N-terminal DNA-binding domain of ARF6 and ARF8 is involved in mediating their interactions with CRY1. Genetic studies showed that ARF6 and ARF8 act partially downstream from CRY1 and PHYB to regulate hypocotyl elongation under blue and red light, respectively. Chromatin immunoprecipitation-PCR assays demonstrated that CRY1 and phyB mediate blue and red light repression of the DNA-binding activity of ARF6 and ARF6-target gene expression, respectively. Altogether, the results herein suggest that the direct repression of auxin-responsive gene expression mediated by the interactions of CRY1 and phyB with ARFs constitutes a new layer of the regulatory mechanisms by which light inhibits auxin-induced hypocotyl elongation.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , DNA de Plantas/metabolismo , Hipocótilo/crescimento & desenvolvimento , Ácidos Indolacéticos/farmacologia , Luz , Arabidopsis/efeitos dos fármacos , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/química , Criptocromos/química , Criptocromos/metabolismo , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Hipocótilo/efeitos dos fármacos , Hipocótilo/metabolismo , Modelos Biológicos , Fitocromo B/metabolismo , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/efeitos da radiação , Domínios Proteicos , Fatores de Transcrição/metabolismo
16.
PLoS Genet ; 11(10): e1005598, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26473486

RESUMO

The precise regulation of microRNA (miRNA) transcription and processing is important for eukaryotic development. Plant miRNAs are first transcribed as stem-loop primary miRNAs (pri-miRNAs) by RNA polymerase II,then cleaved in the nucleus into mature miRNAs by Dicer-like 1 (DCL1). We identified a cycling DOF transcription factor, CDF2, which interacts with DCL1 and regulates the accumulation of a population of miRNAs. CDF2 binds directly to the promoters of some miRNAs and works as a transcription activator or repressor for these miRNA genes. CDF2 binds preferentially to the pri-miRNAs regulated by itself and affects DCL1-mediated processing of these pri-miRNAs. Genetically, CDF2 works in the same pathway as miR156 or miR172 to control flowering. We conclude that CDF2 regulates a group of pri-miRNAs at both the transcriptional and posttranscriptional levels to maintain proper levels of their mature miRNAs to control plant development.


Assuntos
Proteínas de Arabidopsis/genética , Proteínas de Ciclo Celular/genética , MicroRNAs/genética , Ribonuclease III/genética , Fatores de Transcrição/genética , Transcrição Gênica , Arabidopsis/genética , Núcleo Celular/genética , Regulação da Expressão Gênica de Plantas , MicroRNAs/biossíntese , RNA Polimerase II/genética , Processamento Pós-Transcricional do RNA
17.
Ecotoxicol Environ Saf ; 163: 172-179, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30053587

RESUMO

Hg contamination is a critical environmental problem, and its remediation using cost-effective and environmentally friendly methods is highly desirable. In this study, a multi-metal-resistant bacterium showing strong Hg(II) volatilization ability, Pseudomonas sp. DC-B1, was isolated from heavy metal-contaminated soils. DC-B1 volatilized 81.1%, 79.2% and 74.3% of the initial Hg2+ from culture solutions with initial Hg2+ concentrations of 5.1, 10.4, and 15.7 mg/L, respectively, within 24 h. Microcosm experiments were performed to investigate the remediation of Hg(II)-spiked soils inoculated with DC-B1 coupled with sawdust biochar amendment. The efficiency of Hg removal from two types of soil samples with different properties and an initial Hg(II) content of approximately 100 mg/kg was enhanced 5.7-13.1% by bio-augmentation with inoculation of the bacterial strain DC-B1, 5.4-10.7% by amendment of 4% (w/w) biochar, and 10.7-23.2% by the combination of DC-B1 and biochar amendments over an incubation period of 24 d over the efficiency in the control treatment under flooded conditions. Longer root lengths were observed in lettuce grown in the treated soils than in lettuce from the control soil, confirming the bioremediation efficacy of the two bioagents for soil Hg contamination.


Assuntos
Biodegradação Ambiental , Carvão Vegetal , Mercúrio/química , Pseudomonas/fisiologia , Poluentes do Solo/química , Solo/química , Recuperação e Remediação Ambiental/métodos , Lactuca/crescimento & desenvolvimento , Metais Pesados/química , Raízes de Plantas/crescimento & desenvolvimento , Pseudomonas/classificação , Especificidade da Espécie , Volatilização
18.
Front Physiol ; 15: 1435157, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39473612

RESUMO

Objective: To identify trends in physical fitness test scores of college freshmen and their physical fitness from 2018 to 2021, and to analyze the relationship between college students' Body Mass Index (BMI) and Physical Fitness Index (PFI). Methods: This study obtained physical fitness test data from 7,541 freshmen at a university in Beijing, China, from 2018 to 2021. Analysis of variance (ANOVA) was used to compare the physical fitness indicators among different BMI levels by gender. A nonlinear quadratic regression model was used to evaluate the relationship between BMI and each indicator within gender groups. Results: The BMI of freshmen in China was generally increased over the study period, and BMI levels influenced students' physical fitness indexes to varying degrees. BMI was significantly correlated with the physical fitness indexes and PFI. The increase in BMI had a greater influence on the PFI of males than females. Conclusion: Students with a normal BMI show better physical fitness. A BMI below or above the normal range may result in poor physical fitness. The relationship between BMI and PFI has an inverted u-shaped curve. Physical education programs should be tailored to students with different fitness levels and fundamentals, including but not limited to the development of strength, speed, and other qualities.

19.
Diagn Microbiol Infect Dis ; 110(4): 116516, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39293320

RESUMO

Respiratory bacterial co-infections are frequently observed in COVID-19 patients. This retrospective study analysed clinical data from patients with COVID-19 and respiratory bacterial co-infections compared to those with COVID-19 alone. The findings suggest that inflammatory markers and lymphocyte subsets may be valuable for the early identification of co-infections in COVID-19 patients.


Assuntos
Infecções Bacterianas , Biomarcadores , COVID-19 , Coinfecção , Subpopulações de Linfócitos , Infecções Respiratórias , SARS-CoV-2 , Humanos , COVID-19/imunologia , COVID-19/complicações , Coinfecção/imunologia , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Biomarcadores/sangue , Infecções Bacterianas/imunologia , Infecções Bacterianas/sangue , Subpopulações de Linfócitos/imunologia , Idoso , SARS-CoV-2/imunologia , Infecções Respiratórias/imunologia , Infecções Respiratórias/virologia , Infecções Respiratórias/microbiologia , Adulto , Inflamação
20.
Infect Drug Resist ; 17: 1643-1652, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38707989

RESUMO

Purpose: The isolation rate of carbapenem-resistant Enterobacter cloacae complex (CREC) is continuously increasing. The aims of this study were to investigate the molecular characteristics and risk factors associated with CREC infections. Methods: Bacterial species were identified using the matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) (Bruker Daltonik GmbH, Bremen, Germany), and the hsp60 gene was utilized for further typing. Antimicrobial susceptibilities were assessed through the MicroScan WalkAway 96 Plus system (Siemens, Germany) and the microbroth dilution method. Antimicrobial resistance genes were screened through polymerase chain reaction (PCR), while the homologous relationship was assessed using multilocus sequence typing (MLST). Conjugation experiments were performed to verify whether the plasmid could be transferred. Additionally, logistic regression model was employed to analyze risk factors for CREC infections. Results: 32 strains of CREC bacteria were isolated during the study, yet only 20 were retained for preservation. While the isolates demonstrated resistance to the majority of antibiotics, they exhibited high sensitivity to polymyxin B and tigecycline. All isolates carried the blaNDM resistance gene, including 13 blaNDM-1 isolates and 7 blaNDM-5 isolates. MLST homology analysis revealed the presence of seven known ST types and one new ST type. Conjugation experiments confirmed that 13 isolates were capable of transferring the blaNDM resistance gene to Escherichia coli strain EC600. Single-factor analysis identified multiple primary risk factors for CREC infection, but multivariate analysis did not reveal independent risk factors. Conclusion: This study investigates the molecular characteristics and risk factors associated with CREC infections. The detection rate of CREC strains in our hospital is continuously rising and homology analysis suggested that strains might spread in our hospital, emphasizing the importance of implementing effective preventive measures to control the horizontal transmission of plasmid-mediated antimicrobial resistance genes.

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