scholarly journals Extended −10 Motif Is Critical for Activity of the cspA Promoter but Does Not Contribute to Low-Temperature Transcription

2005 ◽  
Vol 187 (18) ◽  
pp. 6584-6589 ◽  
Author(s):  
Sangita Phadtare ◽  
Konstantin Severinov
Keyword(s):  
Low Temperature ◽  
Cold Shock ◽  
Cold Shock Protein ◽  
Mrna Stabilization ◽  
Cold Sensitive ◽  
Temperature Downshift ◽  
Cspa Promoter ◽  
High Level

ABSTRACT Bacterial promoters belonging to the extended −10 class contain a conserved TGn motif upstream of the −10 promoter consensus element. Open promoter complexes can be formed on some extended −10 Escherichia coli promoters at temperatures as low as 6°C, when complexes on most promoters are closed. The promoter of cspA, a gene that codes for the major cold shock protein CspA of E. coli, contains an extended −10 motif. CspA is dramatically induced upon temperature downshift from 37 to 15°C, and its cold shock induction has been attributed to transcription, translation, and mRNA stabilization effects. Here, we show that though the extended −10 motif is critical for high-level expression of cspA, it does not contribute to low-temperature expression. In fact, transcription from the wild-type cspA promoter is cold sensitive in vitro and in vivo. Thus, transcription appears to play little or no role in low-temperature induction of cspA expression.

scholarly journals Role of the Cold-Box Region in the 5′ Untranslated Region of the cspA mRNA in Its Transient Expression at Low Temperature in Escherichia coli

1998 ◽  
Vol 180 (1) ◽  
pp. 90-95 ◽  
Author(s):  
Li Fang ◽  
Yan Hou ◽  
Masayori Inouye
Keyword(s):  
Escherichia Coli ◽  
Low Temperature ◽  
Untranslated Region ◽  
Cold Shock ◽  
Wild Type ◽  
Mrna Stabilization ◽  
High Level ◽  
Cold Box ◽  
In Cells

ABSTRACT Upon temperature downshift, a group of proteins called cold shock proteins, such as CspA, CspB, and CsdA, are transiently induced inEscherichia coli. However, when the 5′ untranslated region (5′ UTR) of cspA mRNA is overproduced at low temperature, the expression of cold shock genes is prolonged or derepressed. It has been proposed that this effect is due to highly conserved 11-base sequences designated the “cold box” existing in the 5′ UTRs ofcspA, cspB, and csdA. Here, we demonstrate that the overproduction of the 5′ UTR of not onlycspA but also cspB and csdA mRNAs causes derepression of all three genes at the same time. Conversely, when the cold-box region was deleted from the cspA 5′ UTR its derepression function was abolished. The amount of mRNA from the chromosomal cspA gene was much higher in cells overproducing the wild-type 5′ UTR by means of a plasmid than it was in cells overproducing the cold-box-deleted 5′ UTR. The stability of the chromosomal cspA mRNA in cells overproducing the wild-type 5′ UTR was almost identical to that in cells overproducing the cold-box-deleted 5′ UTR. Therefore, the derepression ofcspA caused by overproduction of 5′ UTR at the end of the acclimation phase occurs at the level of transcription but not by mRNA stabilization, indicating that the cold-box region plays a negative role in cspA transcription in cold shock-adapted cells. The role of the cold-box region was further confirmed with acspA mutant strain containing a cold-box-deletedcspA gene integrated into the chromosome, which showed a high level of constitutive production of CspA but not CspB during exponential growth at low temperature.

scholarly journals A Temperature-Independent Cold-Shock Protein Homolog Acts as a Virulence Factor in Xylella fastidiosa

2016 ◽  
Vol 29 (5) ◽  
pp. 335-344 ◽  
Author(s):  
Lindsey P. Burbank ◽  
Drake C. Stenger
Keyword(s):  
Deletion Mutant ◽  
Cold Shock ◽  
Rna Binding ◽  
Xylella Fastidiosa ◽  
Cold Shock Protein ◽  
Plant Colonization ◽  
Wild Type ◽  
Cold Temperatures ◽  
Mrna Stabilization

Xylella fastidiosa, causal agent of Pierce’s disease (PD) of grapevine, is a fastidious organism that requires very specific conditions for replication and plant colonization. Cold temperatures reduce growth and survival of X. fastidiosa both in vitro and in planta. However, little is known regarding physiological responses of X. fastidiosa to temperature changes. Cold-shock proteins (CSP), a family of nucleic acid–binding proteins, act as chaperones facilitating translation at low temperatures. Bacterial genomes often encode multiple CSP, some of which are strongly induced following exposure to cold. Additionally, CSP contribute to the general stress response through mRNA stabilization and posttranscriptional regulation. A putative CSP homolog (Csp1) with RNA-binding activity was identified in X. fastidiosa Stag’s Leap. The csp1 gene lacked the long 5′ untranslated region characteristic of cold-inducible genes and was expressed in a temperature-independent manner. As compared with the wild type, a deletion mutant of csp1 (∆csp1) had decreased survival rates following cold exposure and salt stress in vitro. The deletion mutant also was significantly less virulent in grapevine, as compared with the wild type, in the absence of cold stress. These results suggest an important function of X. fastidiosa Csp1 in response to cellular stress and during plant colonization.

scholarly journals A cold shock protein promotes high-temperature microbial growth through binding to diverse RNA species

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Zikang Zhou ◽  
Hongzhi Tang ◽  
Weiwei Wang ◽  
Lige Zhang ◽  
Fei Su ◽  
...  
Keyword(s):  
High Temperature ◽  
Cold Shock ◽  
Rna Binding ◽  
Cold Shock Protein ◽  
Mrna Accumulation ◽  
Temperature Resistance ◽  
High Temperature Resistance ◽  
Biomass Increase

AbstractEndowing mesophilic microorganisms with high-temperature resistance is highly desirable for industrial microbial fermentation. Here, we report a cold-shock protein (CspL) that is an RNA chaperone protein from a lactate producing thermophile strain (Bacillus coagulans 2–6), which is able to recombinantly confer strong high-temperature resistance to other microorganisms. Transgenic cspL expression massively enhanced high-temperature growth of Escherichia coli (a 2.4-fold biomass increase at 45 °C) and eukaryote Saccharomyces cerevisiae (a 2.6-fold biomass increase at 36 °C). Importantly, we also found that CspL promotes growth rates at normal temperatures. Mechanistically, bio-layer interferometry characterized CspL’s nucleotide-binding functions in vitro, while in vivo we used RNA-Seq and RIP-Seq to reveal CspL’s global effects on mRNA accumulation and CspL’s direct RNA binding targets, respectively. Thus, beyond establishing how a cold-shock protein chaperone provides high-temperature resistance, our study introduces a strategy that may facilitate industrial thermal fermentation.

scholarly journals Aberrantly high activation of a FoxM1–STMN1 axis contributes to progression and tumorigenesis in FoxM1-driven cancers

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Jun Liu ◽  
Jipeng Li ◽  
Ke Wang ◽  
Haiming Liu ◽  
Jianyong Sun ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Poor Prognosis ◽  
Soft Agar ◽  
Transcriptional Level ◽  
Regulation Mechanism ◽  
Strong Positive Correlation ◽  
Cell Viability Assay ◽  
High Level

AbstractFork-head box protein M1 (FoxM1) is a transcriptional factor which plays critical roles in cancer development and progression. However, the general regulatory mechanism of FoxM1 is still limited. STMN1 is a microtubule-binding protein which can inhibit the assembly of microtubule dimer or promote depolymerization of microtubules. It was reported as a major responsive factor of paclitaxel resistance for clinical chemotherapy of tumor patients. But the function of abnormally high level of STMN1 and its regulation mechanism in cancer cells remain unclear. In this study, we used public database and tissue microarrays to analyze the expression pattern of FoxM1 and STMN1 and found a strong positive correlation between FoxM1 and STMN1 in multiple types of cancer. Lentivirus-mediated FoxM1/STMN1-knockdown cell lines were established to study the function of FoxM1/STMN1 by performing cell viability assay, plate clone formation assay, soft agar assay in vitro and xenograft mouse model in vivo. Our results showed that FoxM1 promotes cell proliferation by upregulating STMN1. Further ChIP assay showed that FoxM1 upregulates STMN1 in a transcriptional level. Prognostic analysis showed that a high level of FoxM1 and STMN1 is related to poor prognosis in solid tumors. Moreover, a high co-expression of FoxM1 and STMN1 has a more significant correlation with poor prognosis. Our findings suggest that a general FoxM1-STMN1 axis contributes to cell proliferation and tumorigenesis in hepatocellular carcinoma, gastric cancer and colorectal cancer. The combination of FoxM1 and STMN1 can be a more precise biomarker for prognostic prediction.

scholarly journals Arabidopsis Disulfide Reductase, Trx-h2, Functions as an RNA Chaperone under Cold Stress

2021 ◽  
Vol 11 (15) ◽  
pp. 6865
Author(s):  
Eun Seon Lee ◽  
Joung Hun Park ◽  
Seong Dong Wi ◽  
Ho Byoung Chae ◽  
Seol Ki Paeng ◽  
...  
Keyword(s):  
Cold Stress ◽  
Wild Type ◽  
Rna Chaperone ◽  
E Coli ◽  
Cold Sensitive ◽  
Thioredoxin H ◽  
Functional Rnas

The thioredoxin-h (Trx-h) family of Arabidopsis thaliana comprises cytosolic disulfide reductases. However, the physiological function of Trx-h2, which contains an additional 19 amino acids at its N-terminus, remains unclear. In this study, we investigated the molecular function of Trx-h2 both in vitro and in vivo and found that Arabidopsis Trx-h2 overexpression (Trx-h2OE) lines showed significantly longer roots than wild-type plants under cold stress. Therefore, we further investigated the role of Trx-h2 under cold stress. Our results revealed that Trx-h2 functions as an RNA chaperone by melting misfolded and non-functional RNAs, and by facilitating their correct folding into active forms with native conformation. We showed that Trx-h2 binds to and efficiently melts nucleic acids (ssDNA, dsDNA, and RNA), and facilitates the export of mRNAs from the nucleus to the cytoplasm under cold stress. Moreover, overexpression of Trx-h2 increased the survival rate of the cold-sensitive E. coli BX04 cells under low temperature. Thus, our data show that Trx-h2 performs function as an RNA chaperone under cold stress, thus increasing plant cold tolerance.

scholarly journals MiR-211 determines brain metastasis specificity through SOX11/NGN2 axis in triple-negative breast cancer

Oncogene ◽  
2021 ◽  
Author(s):  
Jhih-Kai Pan ◽  
Cheng-Han Lin ◽  
Yao-Lung Kuo ◽  
Luo-Ping Ger ◽  
Hui-Chuan Cheng ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Brain Metastasis ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Survival Outcomes ◽  
Poor Survival ◽  
Breast Cancer Brain Metastasis ◽  
High Level

AbstractBrian metastasis, which is diagnosed in 30% of triple-negative breast cancer (TNBC) patients with metastasis, causes poor survival outcomes. Growing evidence has characterized miRNAs involving in breast cancer brain metastasis; however, currently, there is a lack of prognostic plasma-based indicator for brain metastasis. In this study, high level of miR-211 can act as brain metastatic prognostic marker in vivo. High miR-211 drives early and specific brain colonization through enhancing trans-blood–brain barrier (BBB) migration, BBB adherence, and stemness properties of tumor cells and causes poor survival in vivo. SOX11 and NGN2 are the downstream targets of miR-211 and negatively regulate miR-211-mediated TNBC brain metastasis in vitro and in vivo. Most importantly, high miR-211 is correlated with poor survival and brain metastasis in TNBC patients. Our findings suggest that miR-211 may be used as an indicator for TNBC brain metastasis.

scholarly journals LINC00680 enhances hepatocellular carcinoma stemness behavior and chemoresistance by sponging miR-568 to upregulate AKT3

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Gege Shu ◽  
Huizhao Su ◽  
Zhiqian Wang ◽  
Shihui Lai ◽  
Yan Wang ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Xenograft Model ◽  
Luciferase Reporter ◽  
Loss Of Function ◽  
Mechanism Study ◽  
Downstream Signaling ◽  
Mouse Xenograft Model ◽  
High Level

Abstract Background Hepatocellular carcinoma (HCC) has an extremely poor prognosis due to the development of chemoresistance, coupled with inherently increased stemness properties. Long non-coding RNAs (LncRNAs) are key regulators for tumor cell stemness and chemosensitivity. Currently the relevance between LINC00680 and tumor progression was still largely unknown, with only one study showing its significance in glioblastoma. The study herein was aimed at identifying the role of LINC00680 in the regulation HCC stemness and chemosensitivity. Methods QRT-PCR was used to detect the expression of LINC00680, miR-568 and AKT3 in tissue specimen and cell lines. Gain- or loss-of function assays were applied to access the function of LINC00680 in HCC cells, including cell proliferation and stemness properties. HCC stemness and chemosensitivity were determined by sphere formation, cell viability and colony formation. Luciferase reporter, RNA immunoprecipitation (RIP), and RNA pull-down assays were performed to examine the interaction between LINC00680 and miR-568 as well as that between miR-568 and AKT3. A nude mouse xenograft model was established for the in vivo study. Results We found that LINC00680 was remarkably upregulated in HCC tissues. Patients with high level of LINC00680 had poorer prognosis. LINC00680 overexpression significantly enhanced HCC cell stemness and decreased in vitro and in vivo chemosensitivity to 5-fluorouracil (5-Fu), whereas LINC00680 knockdown led to opposite results. Mechanism study revealed that LINC00680 regulated HCC stemness and chemosensitivity through sponging miR-568, thereby expediting the expression of AKT3, which further activated its downstream signaling molecules, including mTOR, elF4EBP1, and p70S6K. Conclusion LINC00680 promotes HCC stemness properties and decreases chemosensitivity through sponging miR-568 to activate AKT3, suggesting that LINC00680 might be a potentially important HCC diagnosis marker and therapeutic target.

scholarly journals Synergistic In Vitro Antiretroviral Activity of a Humanized Monoclonal Anti-CD4 Antibody (TNX-355) and Enfuvirtide (T-20)

2006 ◽  
Vol 50 (6) ◽  
pp. 2231-2233 ◽  
Author(s):  
Xing-Quan Zhang ◽  
Meredith Sorensen ◽  
Michael Fung ◽  
Robert T. Schooley
Keyword(s):  
Viral Replication ◽  
Viral Entry ◽  
Antiretroviral Agents ◽  
Entry Inhibitors ◽  
High Level ◽  
Antiretroviral Activity

ABSTRACT Recently, antiretroviral agents directed at several steps involved in viral entry have been shown to reduce viral replication in vitro and in vivo. We have demonstrated a high level of in vitro synergistic antiretroviral activity for two entry inhibitors that are directed at sequential steps in the entry process.

scholarly journals Differential expression and regulation of Tdo2 during mouse decidualization

2013 ◽  
Vol 220 (1) ◽  
pp. 73-83 ◽  
Author(s):  
Dang-Dang Li ◽  
Ying-Jie Gao ◽  
Xue-Chao Tian ◽  
Zhan-Qing Yang ◽  
Hang Cao ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Differential Expression ◽  
Stromal Cells ◽  
Real Time Pcr ◽  
Mouse Uterus ◽  
Decidual Cells ◽  
High Level ◽  
Rate Limiting

Tryptophan 2,3-dioxygenase (Tdo2) is a rate-limiting enzyme which directs the conversion of tryptophan to kynurenine. The aim of this study was to examine the expression and regulation of Tdo2 in mouse uterus during decidualization. Tdo2 mRNA was mainly expressed in the decidua on days 6–8 of pregnancy. By real-time PCR, a high level of Tdo2 expression was observed in the uteri from days 6 to 8 of pregnancy, although Tdo2 expression was observed on days 1–8. Simultaneously, Tdo2 mRNA was also detected under in vivo and in vitro artificial decidualization. Estrogen, progesterone, and 8-bromoadenosine-cAMP could induce the expression of Tdo2 in the ovariectomized mouse uterus and uterine stromal cells. Tdo2 could regulate cell proliferation and stimulate the expression of decidual marker Dtprp in the uterine stromal cells and decidual cells. Overexpression of Tdo2 could upregulate the expression of Ahr, Cox2, and Vegf genes in uterine stromal cells, while Tdo2 inhibitor 680C91 could downregulate the expression of Cox2 and Vegf genes in uterine decidual cells. These data indicate that Tdo2 may play an important role during mouse decidualization and be regulated by estrogen, progesterone, and cAMP.

scholarly journals Arabidopsis ADF5 Acts as a Downstream Target Gene of CBFs in Response to Low-Temperature Stress

2021 ◽  
Vol 9 ◽  
Author(s):  
Pan Zhang ◽  
Dong Qian ◽  
Changxin Luo ◽  
Yingzhi Niu ◽  
Tian Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Actin Cytoskeleton ◽  
Temperature Stress ◽  
Regulatory Element ◽  
Low Temperature Stress ◽  
Knockout Mutant ◽  
Triple Mutant ◽  
Freezing Resistance

Low temperature is a major adverse environment that affects normal plant growth. Previous reports showed that the actin cytoskeleton plays an important role in the plant response to low-temperature stress, but the regulatory mechanism of the actin cytoskeleton in this process is not clear. C-repeat binding factors (CBFs) are the key molecular switches for plants to adapt to cold stress. However, whether CBFs are involved in the regulation of the actin cytoskeleton has not been reported. We found that Arabidopsis actin depolymerizing factor 5 (ADF5), an ADF that evolved F-actin bundling function, was up-regulated at low temperatures. We also demonstrated that CBFs bound to the ADF5 promoter directly in vivo and in vitro. The cold-induced expression of ADF5 was significantly inhibited in the cbfs triple mutant. The freezing resistance of the adf5 knockout mutant was weaker than that of wild type (WT) with or without cold acclimation. After low-temperature treatment, the actin cytoskeleton of WT was relatively stable, but the actin cytoskeletons of adf5, cbfs, and adf5 cbfs were disturbed to varying degrees. Compared to WT, the endocytosis rate of the amphiphilic styryl dye FM4-64 in adf5, cbfs, and adf5 cbfs at low temperature was significantly reduced. In conclusion, CBFs directly combine with the CRT/DRE DNA regulatory element of the ADF5 promoter after low-temperature stress to transcriptionally activate the expression of ADF5; ADF5 further regulates the actin cytoskeleton dynamics to participate in the regulation of plant adaptation to a low-temperature environment.

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