scholarly journals PERP, an apoptosis-associated target of p53, is a novel member of the PMP-22/gas3 family

2000 ◽  
Vol 14 (6) ◽  
pp. 704-718 ◽  
Author(s):  
Laura D. Attardi ◽  
Elizabeth E. Reczek ◽  
Corinna Cosmas ◽  
Elizabeth G. Demicco ◽  
Mila E. McCurrach ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Target Genes ◽  
Sequence Similarity ◽  
Cell System ◽  
Dependent Manner ◽  
Apoptosis Pathway ◽  
Adenovirus E1a ◽  
Cycle Arrest ◽  
P53 Target Genes

The p53 tumor suppressor activates either cell cycle arrest or apoptosis in response to cellular stress. Mouse embryo fibroblasts (MEFs) provide a powerful primary cell system to study both p53-dependent pathways. Specifically, in response to DNA damage, MEFs undergo p53-dependent G1 arrest, whereas MEFs expressing the adenovirus E1A oncoprotein undergo p53-dependent apoptosis. As the p53-dependent apoptosis pathway is not well understood, we sought to identify apoptosis-specific p53 target genes using a subtractive cloning strategy. Here, we describe the characterization of a gene identified in this screen, PERP, which is expressed in a p53-dependent manner and at high levels in apoptotic cells compared with G1-arrested cells. PERP induction is linked to p53-dependent apoptosis, including in response to E2F-1-driven hyperproliferation. Furthermore, analysis of the PERP promoter suggests that PERP is directly activated by p53. PERP shows sequence similarity to the PMP-22/gas3 tetraspan membrane protein implicated in hereditary human neuropathies such as Charcot–Marie–Tooth. Like PMP-22/gas3, PERP is a plasma membrane protein, and importantly, its expression causes cell death in fibroblasts. Taken together, these data suggest that PERP is a novel effector of p53-dependent apoptosis.

scholarly journals Cloning and Characterization of theFlavobacterium johnsoniae Gliding Motility GenesgldD and gldE

2001 ◽  
Vol 183 (14) ◽  
pp. 4167-4175 ◽  
Author(s):  
David W. Hunnicutt ◽  
Mark J. McBride
Keyword(s):  
Membrane Protein ◽  
Cytoplasmic Membrane ◽  
Sequence Similarity ◽  
Gliding Motility ◽  
Wild Type ◽  
Bacteriophage Infection ◽  
Flavobacterium Johnsoniae ◽  
Latex Spheres ◽  
Serovar Typhimurium

ABSTRACT Cells of Flavobacterium johnsoniae move over surfaces by a process known as gliding motility. The mechanism of this form of motility is not known. Cells of F. johnsoniaepropel latex spheres along their surfaces, which is thought to be a manifestation of the motility machinery. Three of the genes that are required for F. johnsoniae gliding motility,gldA, gldB, and ftsX, have recently been described. Tn4351 mutagenesis was used to identify another gene, gldD, that is needed for gliding. Tn4351-induced gldD mutants formed nonspreading colonies, and cells failed to glide. They also lacked the ability to propel latex spheres and were resistant to bacteriophages that infect wild-type cells. Introduction of wild-type gldD into the mutants restored motility, ability to propel latex spheres, and sensitivity to bacteriophage infection. gldD codes for a cytoplasmic membrane protein that does not exhibit strong sequence similarity to proteins of known function. gldE, which lies immediately upstream ofgldD, encodes another cytoplasmic membrane protein that may be involved in gliding motility. Overexpression ofgldE partially suppressed the motility defects of agldB point mutant, suggesting that GldB and GldE may interact. GldE exhibits sequence similarity to Borrelia burgdorferi TlyC and Salmonella enterica serovar Typhimurium CorC.

scholarly journals Targeting the PI5P4K lipid kinase family in cancer using novel covalent inhibitors

2019 ◽  
Author(s):  
Sindhu Carmen Sivakumaren ◽  
Hyeseok Shim ◽  
Tinghu Zhang ◽  
Fleur M. Ferguson ◽  
Mark R. Lundquist ◽  
...  
Keyword(s):  
Cancer Metabolism ◽  
Target Genes ◽  
Therapeutic Potential ◽  
Dependent Manner ◽  
Cancer Cell Proliferation ◽  
Lipid Kinase ◽  
Covalent Inhibitors ◽  
Lipid Kinases ◽  
Disordered Loop

SummaryThe PI5P4Ks have been demonstrated to be important for cancer cell proliferation and other diseases. However, the therapeutic potential of targeting these kinases is understudied due to a lack of potent, specific small molecules available. Here we present the discovery and characterization of a novel pan-PI5P4K inhibitor, THZ-P1-2, that covalently targets cysteines on a disordered loop in PI5P4Kα/β/γ. THZ-P1-2 demonstrates cellular on-target engagement with limited off-targets across the kinome. AML/ALL cell lines were sensitive to THZ-P1-2, consistent with PI5P4K’s reported role in leukemogenesis. THZ-P1-2 causes autophagosome clearance defects and upregulation in TFEB nuclear localization and target genes, disrupting autophagy in a covalent-dependent manner and phenocopying the effects of PI5P4K genetic deletion. Our studies demonstrate that PI5P4Ks are tractable targets, with THZ-P1-2 as a useful tool to further interrogate the therapeutic potential of PI5P4K inhibition and inform drug discovery campaigns for these lipid kinases in cancer metabolism and other autophagy-dependent disorders.

scholarly journals New Insights into the Pleiotropic Drug Resistance Network from Genome-Wide Characterization of the YRR1 Transcription Factor Regulation System

2002 ◽  
Vol 22 (8) ◽  
pp. 2642-2649 ◽  
Author(s):  
Stéphane Le Crom ◽  
Frédéric Devaux ◽  
Philippe Marc ◽  
Xiaoting Zhang ◽  
W. Scott Moye-Rowley ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Transcription Factor ◽  
Binding Site ◽  
Time Course ◽  
Target Genes ◽  
Regulation System ◽  
Dependent Manner ◽  
Pleiotropic Drug Resistance ◽  
Genome Wide

ABSTRACT Yrr1p is a recently described Zn2Cys6 transcription factor involved in the pleiotropic drug resistance (PDR) phenomenon. It is controlled in a Pdr1p-dependent manner and is autoregulated. We describe here a new genome-wide approach to characterization of the set of genes directly regulated by Yrr1p. We found that the time-course production of an artificial chimera protein containing the DNA-binding domain of Yrr1p activated the 15 genes that are also up-regulated by a gain-of-function mutant of Yrr1p. Gel mobility shift assays showed that the promoters of the genes AZR1, FLR1, SNG1, YLL056C, YLR346C, and YPL088W interacted with Yrr1p. The putative consensus Yrr1p binding site deduced from these experiments, (T/A)CCG(C/T)(G/T)(G/T)(A/T)(A/T), is strikingly similar to the PDR element binding site sequence recognized by Pdr1p and Pdr3p. The minor differences between these sequences are consistent with Yrr1p and Pdr1p and Pdr3p having different sets of target genes. According to these data, some target genes are directly regulated by Pdr1p and Pdr3p or by Yrr1p, whereas some genes are indirectly regulated by the activation of Yrr1p. Some genes, such as YOR1, SNQ2, and FLR1, are clearly directly controlled by both classes of transcription factor, suggesting an important role for the corresponding membrane proteins.

scholarly journals Regulation of p53 Target Gene Expression by Peptidylarginine Deiminase 4

2008 ◽  
Vol 28 (15) ◽  
pp. 4745-4758 ◽  
Author(s):  
Pingxin Li ◽  
Hongjie Yao ◽  
Zhiqiang Zhang ◽  
Ming Li ◽  
Yuan Luo ◽  
...  
Keyword(s):  
Target Gene ◽  
Target Genes ◽  
Peptidylarginine Deiminase ◽  
Uv Treatment ◽  
Rna Pol Ii ◽  
Pol Ii ◽  
Cycle Arrest ◽  
P53 Target Gene ◽  
P53 Target Genes ◽  
P21 Promoter

ABSTRACT Histone Arg methylation has been correlated with transcriptional activation of p53 target genes. However, whether this modification is reversed to repress the expression of p53 target genes is unclear. Here, we report that peptidylarginine deiminase 4, a histone citrullination enzyme, is involved in the repression of p53 target genes. Inhibition or depletion of PAD4 elevated the expression of a subset of p53 target genes, including p21/CIP1/WAF1, leading to cell cycle arrest and apoptosis. Moreover, the induction of p21, cell cycle arrest, and apoptosis by PAD4 depletion is p53 dependent. Protein-protein interaction studies showed an interaction between p53 and PAD4. Chromatin immunoprecipitation assays showed that PAD4 is recruited to the p21 promoter in a p53-dependent manner. RNA polymerase II (Pol II) activities and the association of PAD4 are dynamically regulated at the p21 promoter during UV irradiation. Paused RNA Pol II and high levels of PAD4 were detected before UV treatment. At early time points after UV treatment, an increase of histone Arg methylation and a decrease of citrullination were correlated with a transient activation of p21. At later times after UV irradiation, a loss of RNA Pol II and an increase of PAD4 were detected at the p21 promoter. The dynamics of RNA Pol II activities after UV treatment were further corroborated by permanganate footprinting. Together, these results suggest a role of PAD4 in the regulation of p53 target gene expression.

SMBA1, a Bax Activator, Induces Cell Cycle Arrest and Apoptosis in Malignant Glioma Cells

Pharmacology ◽  
2019 ◽  
Vol 105 (3-4) ◽  
pp. 164-172
Author(s):  
Shuangbo Fan ◽  
Qian Xu ◽  
Liang Wang ◽  
Yulin Wan ◽  
Sheng Qiu
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Biological Effects ◽  
Cyclin B1 ◽  
Dependent Manner ◽  
Apoptosis Pathway ◽  
Cycle Arrest ◽  
Intrinsic Apoptosis Pathway ◽  
Induced Apoptosis ◽  
Dose Dependent

SMBA1 (small-molecule Bax agonists 1), a small molecular activator of Bax, is a potential anti-tumour agent. In the present study, we investigated the biological effects of SMBA1 on glioblastoma (GBM) cells. SMBA1 reduced the viabilities of U87MG, U251 and T98G cells in a time- and dose-dependent manner. Moreover, treatment with SMBA1 induced cell cycle arrest at the G2/M phase transition, accompanied by the downregulation of Cdc25c and cyclin B1 and the upregulation of p21. SMBA1 also induced apoptosis of GBM cells in a dose-dependent manner. Mechanistically, SMBA1 induced apoptosis via the intrinsic pathway. Silencing of Bax or ectopic expression of Bcl-2 significantly inhibited SMBA1-induced apoptosis. Moreover, SMBA1 inhibited the growth of U87MG xenograft tumours in vivo. Overall, SMBA1 shows anti-proliferative effects against GBM cells through activation of the intrinsic apoptosis pathway.

scholarly journals Characterization of YmgF, a 72-Residue Inner Membrane Protein That Associates with the Escherichia coli Cell Division Machinery

2008 ◽  
Vol 191 (1) ◽  
pp. 333-346 ◽  
Author(s):  
Gouzel Karimova ◽  
Carine Robichon ◽  
Daniel Ladant
Keyword(s):  
Escherichia Coli ◽  
Cell Division ◽  
Membrane Protein ◽  
Integral Membrane Protein ◽  
Dependent Manner ◽  
E Coli ◽  
Division Site ◽  
Inner Membrane Protein ◽  
Two Hybrid

ABSTRACT Formation of the Escherichia coli division septum is catalyzed by a number of essential proteins (named Fts) that assemble into a ring-like structure at the future division site. Many of these Fts proteins are intrinsic transmembrane proteins whose functions are largely unknown. In the present study, we attempted to identify a novel putative component(s) of the E. coli cell division machinery by searching for proteins that could interact with known Fts proteins. To do that, we used a bacterial two-hybrid system based on interaction-mediated reconstitution of a cyclic AMP (cAMP) signaling cascade to perform a library screening in order to find putative partners of E. coli cell division protein FtsL. Here we report the characterization of YmgF, a 72-residue integral membrane protein of unknown function that was found to associate with many E. coli cell division proteins and to localize to the E. coli division septum in an FtsZ-, FtsA-, FtsQ-, and FtsN-dependent manner. Although YmgF was previously shown to be not essential for cell viability, we found that when overexpressed, YmgF was able to overcome the thermosensitive phenotype of the ftsQ1(Ts) mutation and restore its viability under low-osmolarity conditions. Our results suggest that YmgF might be a novel component of the E. coli cell division machinery.

scholarly journals PRIC295, a Nuclear Receptor Coactivator, Identified from PPAR-Interacting Cofactor Complex

PPAR Research ◽  
2010 ◽  
Vol 2010 ◽  
pp. 1-16 ◽  
Author(s):  
Sean R. Pyper ◽  
Navin Viswakarma ◽  
Yuzhi Jia ◽  
Yi-Jun Zhu ◽  
Joseph D. Fondell ◽  
...  
Keyword(s):  
Nuclear Receptor ◽  
Target Genes ◽  
Peroxisome Proliferator ◽  
Dependent Manner ◽  
Peroxisome Proliferator Activated Receptor ◽  
Nuclear Receptor Coactivator ◽  
Evolutionarily Conserved

The peroxisome proliferator-activated receptor- (PPAR) plays a key role in lipid metabolism and energy combustion. Chronic activation of PPAR in rodents leads to the development of hepatocellular carcinomas. The ability of PPAR to induce expression of its target genes depends on Mediator, an evolutionarily conserved complex of cofactors and, in particular, the subunit 1 (Med1) of this complex. Here, we report the identification and characterization of PPAR-interacting cofactor (PRIC)-295 (PRIC295), a novel coactivator protein, and show that it interacts with the Med1 and Med24 subunits of the Mediator complex. PRIC295 contains 10 LXXLL signature motifs that facilitate nuclear receptor binding and interacts with PPAR and five other members of the nuclear receptor superfamily in a ligand-dependent manner. PRIC295 enhances the transactivation function of PPAR, PPAR, and ER. These data demonstrate that PRIC295 interacts with nuclear receptors such as PPAR and functions as a transcription coactivator underin vitroconditions and may play an important role in mediating the effectsin vivoas a member of the PRIC complex with Med1 and Med24.

scholarly journals Aspirin inhibits tumor progression and enhances cisplatin sensitivity in epithelial ovarian cancer

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11591
Author(s):  
Jianfeng Guo ◽  
Yapei Zhu ◽  
Lili Yu ◽  
Yuan Li ◽  
Jing Guo ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Tumor Growth ◽  
Growth Inhibition ◽  
Epithelial Ovarian Cancer ◽  
Target Genes ◽  
Tumor Growth Inhibition ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
P53 Target Genes

Background Ovarian cancer is the most common gynecological malignancy and is difficult to manage due to the emergence of resistance to various chemotherapeutic drugs. New efforts are urgently awaited. Aspirin, which is traditionally considered a nonsteroidal anti-inflammatory drug (NSAID), has been reported to exert potential chemopreventive effects. Therefore, we aimed to investigate the anticancer effect and explore the underlying molecular mechanisms of aspirin on epithelial ovarian cancer (EOC) cells. Methods We conducted wound healing, transwell migration, EdU cell proliferation, colony formation and apoptosis detection assays to observe the effects of aspirin on the migration, proliferation and apoptosis of EOC cells (A2870, Caov-3, and SK-OV-3). EOC cells were treated with a combination of aspirin and cisplatin (CDDP) to observe the effect of aspirin on enhancing CDDP sensitivity. Orthotopic xenograft models of ovarian cancer established with A2780-Luciferase-GFP cells were applied to compare tumor growth inhibition in the control, CDDP and CDDP plus aspirin groups through in vivo imaging, which can be used to continuously monitor tumor growth. The expression and acetylation levels of p53 in EOC cells treated with aspirin were determined using western blotting, and p53 acetylation levels were examined in tumors harvested from the transplanted mice. Quantitative real-time PCR was used to assess the mRNA expression of p53 target genes. Results Aspirin inhibited migration and proliferation and induced apoptosis in EOC cell lines in a concentration-dependent manner. In vitro, aspirin enhanced the sensitivity of EOC cells to CDDP by increasing its inhibitory effect on proliferation and its effect on inducing apoptosis. In vivo, the differences in the tumor growth inhibition rates among the different CDDP experimental groups were statistically significant (p < 0.05). Aspirin did not affect p53 protein expression but increased the p53 acetylation level in a concentration-dependent manner. In addition, the mRNA levels of CDKN1A, BAX, FOXF1, PUMA, and RRAD in EOC cells were significantly increased by the aspirin treatment. Conclusions Aspirin inhibits tumor progression and enhances the CDDP sensitivity of EOC cells. These antitumor effects of aspirin might be mediated by p53 acetylation and subsequent activation of p53 target genes.

scholarly journals FLIP(L) determines p53 induced life or death

2019 ◽  
Author(s):  
Andrea Lees ◽  
Alexander J. McIntyre ◽  
Fiammetta Falcone ◽  
Nyree T. Crawford ◽  
Christopher McCann ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Cycle Arrest ◽  
Cell Fate ◽  
Target Genes ◽  
Hdac Inhibitors ◽  
Caspase 8 ◽  
Cycle Arrest ◽  
P53 Activation ◽  
P53 Target Genes ◽  
Mdm2 Inhibitor

AbstractHow p53 differentially activates cell cycle arrest versus cell death remains poorly understood. Here, we demonstrate that upregulation of canonical pro-apoptotic p53 target genes in colon cancer cells imposes a critical dependence on the long splice form of the caspase-8 regulator FLIP (FLIP(L)), which we identify as a direct p53 transcriptional target. Inhibiting FLIP(L) expression with siRNA or Class-I HDAC inhibitors promotes apoptosis in response to p53 activation by the MDM2 inhibitor Nutlin-3A, which otherwise predominantly induces cell-cycle arrest. When FLIP(L) upregulation is inhibited, apoptosis is induced in response to p53 activation via a novel ligand-independent TRAIL-R2/caspase-8 complex, which, by activating BID, induces mitochondrial-mediated apoptosis. Notably, FLIP(L) depletion inhibits p53-induced expression of the cell cycle regulator p21 and enhances p53-mediated upregulation of PUMA, with the latter activating mitochondrial-mediated apoptosis in FLIP(L)-depleted, Nutlin-3A-treated cells lacking TRAIL-R2/caspase-8. Thus, we report two previously undescribed, novel FLIP(L)-dependent mechanisms that determine cell fate following p53 activation.

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