Expression of Regucalcin, a calcium-binding protein is regulated by hypoxia-inducible factor-1α.

Regucalcin (RGN) regulates intracellular Ca2+ homeostasis and the activity of several proteins involved in intracellular signaling pathways, which highlights its importance in cell biology. Regucalcin has cytoprotective effects reducing intracellular levels of oxidative stress, also playing a crucial role in the control of cell survival and apoptosis. In an effort to assess its gene regulation, we initially identified the expression of Regucalcin in rat lungs treated with hypoxia at various time points. Previously, HIF-1α expression was also reported to be upregulated in hypoxia. Interestingly hypoxic induced Regucalcin expression in a fashion similar to that of HIF-1α expression in rat lungs. Sequence analysis of the Regucalcin promoter region revealed the presence of putative HRE binding motifs. Further analysis of the 1 kb Regucalcin promoter region with 5' deletion and point mutants of HRE binding motif showed that the HRE binding site was critical for high promoter activity. In addition, HIF-1α protein binds directly to the HRE binding motifs within the Regucalcin promoter in-vivo, and regulates Regucalcin gene expression. All together, these findings suggest that Regucalcin is the novel target gene of HIF-1α and that Regucalcin gene expression in hypoxia may be regulated by the control of HIF-1α expression.

Heterogenous chemosensitivity of a panel of organoid lines derived from small cell neuroendocrine carcinoma of the uterine cervix.

Small cell neuroendocrine carcinoma (SCNEC) of the uterine cervix is a rare disease with a poor prognosis. The lack of established disease models has hampered therapy development. We generated a panel of cancer tissue-originated spheroid (CTOS) lines derived from SCNEC of the uterine cervix using a method based upon cell-cell contact throughout the preparation and culturing processes. Using 11 CTOS lines, we assessed the sensitivity of various drugs used in clinical practice. Drug sensitivity assays revealed significant heterogeneous inter-CTOS chemosensitivity. Microarray analyses were then performed to identify sensitivity-related gene signatures. Specific gene sets were identified which likely contribute to the sensitivity to the tested drugs. We identified a line (Cerv54) that was exceptionally sensitive to irinotecan. Cerv54 had increased levels of CES1, which catalyzes the conversion of irinotecan to the active form, SN38, although in Cerv54 cells, SN38 was undetectable, CES1 expression and activity were markedly low compared to the liver, and a CES1 inhibitor had no effect on irinotecan sensitivity. These results suggested a novel irinotecan mode of action in Cerv54. Our CTOS lines may be useful for understanding the variation and mechanism of drug sensitivity, contributing to the understanding and development of chemotherapeutic drugs.

Atg15 in Saccharomyces cerevisiae consists of two functionally distinct domains.

Autophagy is a cellular degradation system widely conserved among eukaryotes. During autophagy, cytoplasmic materials fated for degradation are compartmentalized in double membrane-bound organelles called autophagosomes. After fusing with the vacuole, their inner membrane-bound structures are released into the vacuolar lumen to become autophagic bodies and eventually degraded by vacuolar hydrolases. Atg15 is a lipase that is essential for disintegration of autophagic body membranes and has a transmembrane domain at the N-terminus and a lipase domain at the C-terminus. However, the roles of the two domains in vivo are not well understood. In this study, we found that the N-terminal domain alone can travel to the vacuole via the multivesicular body pathway, and that targeting of the C-terminal lipase domain to the vacuole is required for degradation of autophagic bodies. Moreover, we found that the C-terminal domain could disintegrate autophagic bodies when it was transported to the vacuole via the Pho8 pathway instead of the multivesicular body pathway. Finally, we identified H435 as one of the residues composing the putative catalytic triad and W466 as an important residue for degradation of autophagic bodies. This study may provide a clue to how the C-terminal lipase domain recognizes autophagic bodies to degrade them.

The novel circular RNA circ-PGAP3 retards cervical cancer growth by regulating the miR-769-5p/p53 axis.

Cervical cancer (CC) is still an intractable disease that seriously affects women's health. Elucidating its pathogenesis will bring new targets for clinical treatment. Circular RNA (circRNA) is an endogenous RNA that has recently been reported to be closely related to cancer progression and development. In the current study, by performing in silico analysis and qRT-PCR assay, we found a circRNA derived from PGAP3, referred as circ-PGAP3 (hsa_circ_0106800, chr17:37843549-37844086), which was significantly downregulated in CC tissues. Low circ-PGAP3 was closely linked to poor prognosis. And overexpression of circ-PGAP3 significantly reduced CC cell proliferation in vitro and tumor growth in vivo. In terms of mechanism, circ-PGAP3 was transcriptionally elevated by p53, a well-recognized tumor suppressor, and circ-PGAP3 was located in the cytoplasm where sponged miR-769-5p to increase the levels of p53 and its downstream targets. Importantly, the regulatory feedback loop of circ-PGAP3/p53 was also confirmed in vivo. Overall, our data clearly expounded the tumor-inhibiting role of circ-PGAP3 in CC, circ-PGAP3 repressed CC tumorigenesis via regulating the miR-769-5p/p53 axis. Therefore, restoration of circ-PGAP3 may be a promising therapeutic target for this thorny disease.

[Evaluation of the Oral Absorption of Ester-type Prodrugs].

The first-pass hydrolysis of oral ester-type prodrugs in the liver and intestine is mediated mainly by hCE1 and hCE2 of the respective predominant carboxylesterase (CES) isozymes. In order to provide high blood concentrations of the parent drugs, it is preferable that prodrugs are absorbed as an intact ester in the intestine, then rapidly converted to active parent drugs by hCE1 in the liver. In the present study, we designed a prodrug of fexofenadine (FXD) as a model parent drug that is resistant to hCE2 but hydrolyzed by hCE1, utilizing the differences in catalytic characteristics of hCE1 and hCE2. In order to precisely predict the intestinal absorption of an FXD prodrug candidate, we developed a novel high-throughput system by modifying Caco-2 cells. Further, we evaluated species differences and aging effects in the intestinal and hepatic hydrolysis of prodrugs to improve the estimation of in vivo first-pass hydrolysis of ester-type prodrugs. Consequently, it was possible to design a hepatotropic prodrug utilizing the differences in tissue distribution and substrate specificity of CESs. In addition, we successfully established three useful in vitro systems for predicting the intestinal absorption of hCE1 substrate using Caco-2 cells. However, some factors involved in estimating the bioavailability of prodrugs in human, such as changes in recognition of drug transporters by esterification, and species differences of the first-pass hydrolysis, should be comprehensively considered in prodrug development.

Bit1-a novel regulator of astrocyte function during retinal development: proliferation, migration, and paracrine effects on vascular endothelial cell.

Studies have shown that astrocyte plays an important role in the formation of retinal vasculature during development. For our study, we investigated the role of Bcl2 inhibitor of transcription 1 (Bit1) in regulating astrocyte function from developing retina and its paracrine effects on vascular endothelial cell. Expression pattern of Bit1 was analyzed by immunofluorescent staining of whole mount rat retina. Astrocytes and retinal microvascular endothelial cells (RMECs) were isolated from rat retina for cultural studies. The proliferation and migration of astrocytes and RMECs were evaluated by CCK-8 assay, scratch assay, and transwell migration assay. Cell apoptosis was detected by anoikis assay. Angiogenesis assay was used to measure the ability of RMECs to form tube-like microvascular structure. siRNA knockdown assay was employed to regulate Bit1 expression in astrocytes. Immunofluorescent staining showed Bit1 expression in migrating retinal astrocytes co-localized with the marker glial fibrillary acidic protein (GFAP). Isolated retinal astrocytes from post-natal rat eyes have an elevated expression of Bit1 and show increased cell survival and decreased anoikis as compared with retinal astrocytes from embryo. Suppressing Bit1 by siRNA assay leads to decreased cell proliferation, migration, and increased anoikis of astrocytes. Meanwhile, Bit1 knockdown could decrease the astrocytic vascular endothelial growth factor (VEGF) expression leading to inhibitory paracrine effects on RMECs angiogenesis. Our findings reveal that Bit1 promotes cell survival, proliferation, migration, and maintains VEGF expression of retinal astrocytes, leading to enhanced paracrine effects on angiogenesis of vascular endothelial cells. Bit1 may serve as a novel regulator of astrocyte biological behaviors interplaying with vascular endothelial cell during retinal development.

[Bit1 mediates the malignant behaviors in pancreatic cancer and its potential clinical significance].

Objective: To investigate the potential role of Bit1 in the pathogenesis of pancreatic ductal cancer cells(PDAC) and its potential clinical application value. Methods: Real-time PCR and Western blot were employed to detect the expression of Bit1 in six pancreatic cancer cells, then the tool cells were selected to further study the function of Bit1.PolyHEMA was used to monitor the suspended cell culture condition in vitro.The invasion and migration abilities of pancreatic cancer cells were detected through Transwell assay. Western blot and confocal assay were used to explore the potential mechanism of Bit1 in the process of metastasis.The expression of Bit1 was detected through tissue microarray, the potential relationship between Bit1 and other clinical factors were analyzed. Results: The results of real-time PCR and Western blot indicated that the expression of Bit1 was highest in the PANC1 cells and lowest in the Mia paca2 cells (gene: 3.13±0.40 vs. 1.00±0.35, protein: 1.77±1.00 vs. 0.23±0.45). The shBit1 PANC1 and Bit1-OE(over expression) Mia paca2 cells were successfully constructed.Bit1 over expression could promote the anoikis rate of Mia paca2 cells, and Bit knockdown could inhibit the anoikis incidence.Bit1 over expression suppressed the motility and invasion of Mia paca2 cells, but Bit1 knockdown could accelerate the migration and invasion ability of PANC1 cells.Bit1 could potentially affect pancreatic cancer cells' malignant behaviors through epithelial-mesenchymal transition process.Bit1 expression was significantly associated with pancreatic cancer's neural invasion (P<0.05). Conclusions: Bit1 could affect the anoikis incidence of pancreatic cancer, Bit1 negatively affect the migration and invasion abilities of PDAC, the EMT process was potentially involved in the whole modulation process.Bit1 expression is associated with neural invasion in pancreatic cancer patients.

Overexpression of AtPAD4 in transgenic Brachypodium distachyon enhances resistance to Puccinia brachypodii.

Brachypodium distachyon (L.) has recently emerged as a model for temperate grasses for investigating the molecular basis of plant-pathogen interactions. Phytoalexin deficient 4 (PAD4) plays a regulatory role in mediating expression of genes involved in plant defence. In this research, we generated transgenic B. distachyon plants constitutively overexpressing AtPAD4. Two transgenic B. distachyon lines were verified using PCR and GUS phenotype. Constitutive expression of AtPAD4 in B. distachyon enhanced resistance to Puccinia brachypodii. P. brachypodii generated less urediniospores on transgenic than on wild-type plants. AtPAD4 overexpression enhanced salicylic acid (SA) levels in B. distachyon-infected tissues. qRT-PCR showed that expression of pathogenesis-related 1 (PR1) and other defence-related genes were up-regulated in transformed B. distachyon following infection with P. brachypodii. Our results indicate that AtPAD4 overexpression in B. distachyon plants led to SA accumulation and induced PR gene expression that reduced the rate of colonisation by P. brachypodii.

AtPME3, a ubiquitous cell wall pectin methylesterase of Arabidopsis thaliana, alters the metabolism of cruciferin seed storage proteins during post-germinative growth of seedlings.

AtPME3 (At3g14310) is a ubiquitous cell wall pectin methylesterase. Atpme3-1 loss-of-function mutants exhibited distinct phenotypes from the wild type (WT), and were characterized by earlier germination and reduction of root hair production. These phenotypical traits were correlated with the accumulation of a 21.5-kDa protein in the different organs of 4-day-old Atpme3-1 seedlings grown in the dark, as well as in 6-week-old mutant plants. Microarray analysis showed significant down-regulation of the genes encoding several pectin-degrading enzymes and enzymes involved in lipid and protein metabolism in the hypocotyl of 4-day-old dark grown mutant seedlings. Accordingly, there was a decrease in proteolytic activity of the mutant as compared with the WT. Among the genes specifying seed storage proteins, two encoding CRUCIFERINS were up-regulated. Additional analysis by RT-qPCR showed an overexpression of four CRUCIFERIN genes in the mutant Atpme3-1, in which precursors of the α- and ß-subunits of CRUCIFERIN accumulated. Together, these results provide evidence for a link between AtPME3, present in the cell wall, and CRUCIFERIN metabolism that occurs in vacuoles.

A high susceptibility to redox imbalance of the transmissible stages of Plasmodium falciparum revealed with a luciferase-based mature gametocyte assay.

The goal to prevent Plasmodium falciparum transmission from humans to mosquitoes requires the identification of targetable metabolic processes in the mature (stage V) gametocytes, the sexual stages circulating in the bloodstream. This task is complicated by the apparently low metabolism of these cells, which renders them refractory to most antimalarial inhibitors and constrains the development of specific and sensitive cell-based assays. Here, we identify and functionally characterize the regulatory regions of the P. falciparum gene PF3D7_1234700, encoding a CPW-WPC protein and named here Upregulated in Late Gametocytes (ULG8), which we have leveraged to express reporter genes in mature male and female gametocytes. Using transgenic parasites containing a pfULG8-luciferase cassette, we investigated the susceptibility of stage V gametocytes to compounds specifically affecting redox metabolism. Our results reveal a high sensitivity of mature gametocytes to the glutathione reductase inhibitor and redox cycler drug methylene blue (MB). Using isobologram analysis, we find that a concomitant inhibition of the parasite enzyme glucose-6-phosphate dehydrogenase-6-phosphogluconolactonase, a key component of NADPH synthesis, potently synergizes MB activity. These data suggest that redox metabolism and detoxification activity play an unsuspected yet vital role in stage V gametocytes, rendering these cells exquisitely sensitive to decreases in NADPH concentration.

The Anoikis Effector Bit1 Inhibits EMT through Attenuation of TLE1-Mediated Repression of E-Cadherin in Lung Cancer Cells.

The mitochondrial Bcl-2 inhibitor of transcription 1 (Bit1) protein is part of an anoikis-regulating pathway that is selectively dependent on integrins. We previously demonstrated that the caspase-independent apoptotic effector Bit1 exerts tumor suppressive function in lung cancer in part by inhibiting anoikis resistance and anchorage-independent growth in vitro and tumorigenicity in vivo. Herein we show a novel function of Bit1 as an inhibitor cell migration and epithelial-mesenchymal transition (EMT) in the human lung adenocarcinoma A549 cell line. Suppression of endogenous Bit1 expression via siRNA and shRNA strategies promoted mesenchymal phenotypes, including enhanced fibroblastoid morphology and cell migratory potential with concomitant downregulation of the epithelial marker E-cadherin expression. Conversely, ectopic Bit1 expression in A549 cells promoted epithelial transition characterized by cuboidal-like epithelial cell phenotype, reduced cell motility, and upregulated E-cadherin expression. Specific downregulation of E-cadherin in Bit1-transfected cells was sufficient to block Bit1-mediated inhibition of cell motility while forced expression of E-cadherin alone attenuated the enhanced migration of Bit1 knockdown cells, indicating that E-cadherin is a downstream target of Bit1 in regulating cell motility. Furthermore, quantitative real-time PCR and reporter analyses revealed that Bit1 upregulates E-cadherin expression at the transcriptional level through the transcriptional regulator Amino-terminal Enhancer of Split (AES) protein. Importantly, the Bit1/AES pathway induction of E-cadherin expression involves inhibition of the TLE1-mediated repression of E-cadherin, by decreasing TLE1 corepressor occupancy at the E-cadherin promoter as revealed by chromatin immunoprecipitation assays. Consistent with its EMT inhibitory function, exogenous Bit1 expression significantly suppressed the formation of lung metastases of A549 cells in an in vivo experimental metastasis model. Taken together, our studies indicate Bit1 is an inhibitor of EMT and metastasis in lung cancer and hence can serve as a molecular target in curbing lung cancer aggressiveness.

Protein Phosphatase Methyl-Esterase PME-1 Protects Protein Phosphatase 2A from Ubiquitin/Proteasome Degradation.

Protein phosphatase 2A (PP2A) is a conserved essential enzyme that is implicated as a tumor suppressor based on its central role in phosphorylation-dependent signaling pathways. Protein phosphatase methyl esterase (PME-1) catalyzes specifically the demethylation of the C-terminal Leu309 residue of PP2A catalytic subunit (PP2Ac). It has been shown that PME-1 affects the activity of PP2A by demethylating PP2Ac, but also by directly binding to the phosphatase active site, suggesting loss of PME-1 in cells would enhance PP2A activity. However, here we show that PME-1 knockout mouse embryonic fibroblasts (MEFs) exhibit lower PP2A activity than wild type MEFs. Loss of PME-1 enhanced poly-ubiquitination of PP2Ac and shortened the half-life of PP2Ac protein resulting in reduced PP2Ac levels. Chemical inhibition of PME-1 and rescue experiments with wild type and mutated PME-1 revealed methyl-esterase activity was necessary to maintain PP2Ac protein levels. Our data demonstrate that PME-1 methyl-esterase activity protects PP2Ac from ubiquitin/proteasome degradation.

[Role of Human Orphan Esterases in Drug-induced Toxicity].

Esterases hydrolyze compounds containing ester, amide, and thioester bonds, causing prodrug activation or detoxification. Among esterases, carboxylesterases have been studied in depth due to their ability to hydrolyze a variety of drugs. However, there are several drugs for which the involved esterase(s) is unknown. We found that flutamide, phenacetin, rifamycins (rifampicin, rifabutin, and rifapentine), and indiplon are hydrolyzed by arylacetamide deacetylase (AADAC), which is highly expressed in human liver and gastrointestinal tissues. Flutamide hydrolysis is considered associated with hepatotoxicity. Phenacetin, a prodrug of acetaminophen, was withdrawn due to side effects such as methemoglobinemia and renal failure. It was demonstrated in vitro and in vivo using mice that AADAC is responsible for phenacetin hydrolysis, which leads to methemoglobinemia. In addition, it was shown that AADAC-mediated hydrolysis attenuates the cytotoxicity of rifamycins. Thus AADAC plays critical roles in drug-induced toxicity. Another orphan esterase, α/ß hydrolase domain containing 10 (ABHD10), was found responsible for deglucuronidation of acyl-glucuronides including mycophenolic acid acyl-glucuronide and probenecid acyl-glucuronide. Because acyl-glucuronides appear associated with toxicity, ABHD10 would function as a detoxification enzyme. The roles of orphan esterases are becoming increasingly understood. Further studies will facilitate our knowledge of the pharmacologic and toxicological significance of orphan esterases in drug therapy.

Structural and functional studies of a Fusarium oxysporum cutinase with polyethylene terephthalate modification potential.

BACKGROUND: Cutinases are serine hydrolases that degrade cutin, a polyester of fatty acids that is the main component of plant cuticle. These biocatalysts have recently attracted increased biotechnological interest due to their potential to modify and degrade polyethylene terephthalate (PET), as well as other synthetic polymers. METHODS: A cutinase from the mesophilic fungus Fusarium oxysporum, named FoCut5a, was expressed either in the cytoplasm or periplasm of Escherichia coli BL21. Its X-ray structure was determined to 1.9Å resolution using molecular replacement. The activity of the recombinant enzyme was tested on a variety of synthetic esters and polyester analogues. RESULTS: The highest production of recombinant FoCut5a was achieved using periplasmic expression at 16°C. Its crystal structure is highly similar to previously determined Fusarium solani cutinase structure. However, a more detailed comparison of the surface properties and amino acid interactions revealed differences with potential impact on the biochemical properties of the two enzymes. FoCut5a showed maximum activity at 40°C and pH 8.0, while it was active on three p-nitrophenyl synthetic esters of aliphatic acids (C(2), C(4), C(12)), with the highest catalytic efficiency for the hydrolysis of the butyl ester. The recombinant cutinase was also found capable of hydrolyzing PET model substrates and synthetic polymers. CONCLUSIONS: The present work is the first reported expression and crystal structure determination of a functional cutinase from the mesophilic fungus F. oxysporum with potential application in surface modification of PET synthetic polymers. GENERAL SIGNIFICANCE: FoCut5a could be used as a biocatalyst in industrial applications for the environmentally-friendly treatment of synthetic polymers.

A defect of the vacuolar putative lipase Atg15 accelerates degradation of lipid droplets through lipolysis.

Lipid droplets (LDs) are the conserved organelles for the deposit of neutral lipids, and function as reservoirs of membrane and energy sources. To date, functional links between autophagy and LD dynamics have not been fully elucidated. Here, we report that a vacuolar putative lipase, Atg15, required for degradation of autophagic bodies, is crucial for the maintenance of LD amount in the yeast Saccharomyces cerevisiae in the stationary phase. Mutant analyses revealed that the putative lipase motif and vacuolar localization of Atg15 are important for the maintenance of LD amount. Loss of autophagosome formation by simultaneous deletion of core ATG genes cancelled the reduction in the LD amount in ATG15-deleted cells, indicating that degradation of autophagic bodies accounts for the functional involvement of Atg15 in LD dynamics. The reduced level of LDs in the mutant strain was dependent on Tgl3 and Tgl4, major lipases for lipolysis in S. cerevisiae. An altered phosphorylation status of Tgl3, higher accumulation of Tgl4, and closer associations of Tgl3 and Tgl4 with LDs were detected in the ATG15-deleted cells. Furthermore, increased levels of downstream metabolites of lipolysis in the mutant strain strongly suggested enhanced lipolytic activity caused by loss of ATG15. Our data provide evidence for a novel link between autophagic flux and LD dynamics integrated with Atg15 activity.

Promotion of testa rupture during garden cress germination involves seed compartment-specific expression and activity of pectin methylesterases.

Pectin methylesterase (PME) controls the methylesterification status of pectins and thereby determines the biophysical properties of plant cell walls, which are important for tissue growth and weakening processes. We demonstrate here that tissue-specific and spatiotemporal alterations in cell wall pectin methylesterification occur during the germination of garden cress (Lepidium sativum). These cell wall changes are associated with characteristic expression patterns of PME genes and resultant enzyme activities in the key seed compartments CAP (micropylar endosperm) and RAD (radicle plus lower hypocotyl). Transcriptome and quantitative real-time reverse transcription-polymerase chain reaction analysis as well as PME enzyme activity measurements of separated seed compartments, including CAP and RAD, revealed distinct phases during germination. These were associated with hormonal and compartment-specific regulation of PME group 1, PME group 2, and PME inhibitor transcript expression and total PME activity. The regulatory patterns indicated a role for PME activity in testa rupture (TR). Consistent with a role for cell wall pectin methylesterification in TR, treatment of seeds with PME resulted in enhanced testa permeability and promoted TR. Mathematical modeling of transcript expression changes in germinating garden cress and Arabidopsis (Arabidopsis thaliana) seeds suggested that group 2 PMEs make a major contribution to the overall PME activity rather than acting as PME inhibitors. It is concluded that regulated changes in the degree of pectin methylesterification through CAP- and RAD-specific PME and PME inhibitor expression play a crucial role during Brassicaceae seed germination.

Clopidogrel bioactivation and risk of bleeding in patients cotreated with angiotensin-converting enzyme inhibitors after myocardial infarction: a proof-of-concept study.

Clopidogrel is an oral antiplatelet prodrug, the majority of which is hydrolyzed to an inactive metabolite by hepatic carboxylesterase 1 (CES1). Most angiotensin-converting enzyme inhibitors (ACEIs) are also metabolized by this enzyme. We examined the effects of ACEIs on clopidogrel bioactivation in vitro and linked the results with a pharmacoepidemiological study. In vitro, ACEIs inhibited CES1-mediated hydrolysis of a model substrate, and trandolapril and enalapril increased formation of clopidogrel active metabolite. In 70,934 patients with myocardial infarction, hazard ratios for clinically significant bleeding in ACEI-treated patients cotreated with or without clopidogrel were 1.10 (95% confidence interval (CI): 0.97-1.25, P = 0.124) and 0.90 (95% CI: 0.81-0.99, P = 0.025), respectively, as compared with patients who did not receive ACEIs. This difference was statistically significant (P = 0.002). We conclude that cotreatment with selected ACEIs and clopidogrel may increase the risk of bleeding. Combination of in vitro and pharmacoepidemiological studies may be a useful paradigm for assessment of drug-drug interactions.

The pharmacogenetics of carboxylesterases: CES1 and CES2 genetic variants and their clinical effect.

Human carboxylesterase 1 (CES1) and carboxylesterase 2 (CES2) are serine esterases responsible for the hydrolysis of ester and amide bonds present in a number of pharmaceutical products. Several common genetic variants of the CES1 and CES2 genes have been shown to influence drug metabolism and clinical outcomes. Polymorphisms of the CES1 gene have been reported to affect the metabolism of dabigatran etexilate, methylphenidate, oseltamivir, imidapril, and clopidogrel, whereas variants of the CES2 gene have been found to affect aspirin and irinotecan. Although the findings of these studies may be preliminary, they demonstrate the potential clinical utility of CES polymorphisms; however, more research is required, especially with respect to CES2. In this review, we outline the functional, molecular, and genetic properties of CES1 and CES2, and highlight recent studies that have shown relations between CES1 and CES2 variants and contemporary pharmacotherapy.

Deinococcus radiodurans can interfere with quorum sensing by producing an AHL-acylase and an AHL-lactonase.

Bacterial communication via the secretion of small diffusible compounds allows microorganisms to regulate gene expression in a coordinated manner. As many virulence traits are regulated in this fashion, disruption of chemical communication has been proposed as novel antimicrobial therapy. Quorum-quenching enzymes have been a promising discovery in this field as they interfere with the communication of Gram-negative bacteria. AHL-lactonases and AHL-acylases have been described in a variety of bacterial strains; however, usually only one of these two groups of enzymes has been described in a single species. We report here the presence of a member of each group of enzymes in the extremophile bacterium Deinococcus radiodurans. Co-occurrence of both enzymes in a single species increases the chance of inactivating foreign AHL signals under different conditions. We demonstrate that both enzymes are able to degrade the quorum-sensing molecules of various pathogens subsequently affecting virulence gene expression. These studies add the quorum-quenching enzymes of D. radiodurans to the list of potent quorum-quenchers and highlight the idea that quorum quenching could have evolved in some bacteria as a strategy to gain a competitive advantage by altering gene expression in other species.

GDSL lipase 1 regulates ethylene signaling and ethylene-associated systemic immunity in Arabidopsis.

Arabidopsis GDSL lipase 1 (GLIP1) has been shown to modulate systemic immunity through the regulation of ethylene signaling components. Here we demonstrate that the constitutive triple response mutant ctr1-1 requires GLIP1 for the ethylene response, gene expression, and pathogen resistance. The glip1-1 mutant was defective in induced resistance following primary inoculation of necrotrophic pathogens, whereas GLIP1-overexpressing plants showed resistance to multiple pathogens. Necrotrophic infection triggered the downregulation of EIN3 and the activation of ERF1 and SID2 in a GLIP1-dependent manner. These results suggest that GLIP1 positively and negatively regulates ethylene signaling, resulting in an ethylene-associated, necrotroph-induced immune response.