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At least 973 records · Page 54

Lysophosphatidic acid receptor-2 (LPA2) and LPA5 regulate cellular functions during tumor progression in fibrosarcoma HT1080 cells

Highlights: • LPAR2 and LPAR5 expressions were elevated by long-term anticancer drug treatment in HT1080 cells. • Highly invasion HT1080-M6 cells were generated from HT1080 cells using Matrigel-coated filters. • HT1080-M6 cell invasion was shown to be 4.5 times higher than that of HT1080 cells. • The cell motile and invasive activities of HT1080-M6 cells were reduced by LPA{sub 2} inhibition. • LPA signaling via LPA{sub 2} is a potent target for the regulation of tumor progression in HT1080 cells. Lysophosphatidic acid (LPA) receptors (LPA{sub 1} to LPA{sub 6}) regulate a variety of malignant properties in cancer cells. In the present study, we investigated the roles of LPA receptors in the promotion of cellular functions during tumor progression in fibrosarcoma cells. To obtain long-term anticancer drug treated cells, human fibrosarcoma HT1080 cells were treated with methotrexate (MTX) and cisplatin (CDDP) for 6 months. LPAR2 and LPAR5 expressions were significantly higher in MTX-treated (HT-MTX) cells than in HT1080 cells. The cell motile and invasive activities of HT-MTX cells were significantly elevated compared with HT1080 cells. Although LPAR5 expression was increased in MTX and CDDP treated (HT-M-C) cells, no change of LPAR2 expression was observed. The cell motile and invasive activities of HT-M-C cells were lower than those of HT1080 cells. Moreover, to evaluate whether LPA receptors promote cell invasive activity, highly invasion (HT1080-M6) cells were established from HT1080 cells. The cell invasive activity of HT1080-M6 cells was approximately 4.5 times higher than HT1080 cell invasion. LPAR2 expression was markedly elevated in HT1080-M6 cells compared with HT1080 cells. The high cell invasion activity of HT1080-M6 cells was significantly suppressed by an antagonist of LPA{sub 2}, H2L5186303. These results suggest that LPA{sub 2} acts as a key regulator of malignant properties in HT1080 cells.

60 APPLIED LIFE SCIENCES↗

Role of c-Myb in the regulation of natural killer cell activity

Highlights: • c-Myb activity was downregulated by TGF-β in natural killer cells. • Celastrol, a c-Myb inhibitor, decreased NK-92 activity at low concentrations. • Celastrol downregulated NKG2D and granzyme B expression. • c-Myb knockdown downregulated NK-92 cytotoxicity and IFN-γ secretion. The regulation of natural killer (NK) cell activity is an important research goal for the development of immunotherapies. In this study, we identified transcription factors affecting NK cell activity. In particular, we screened transcription factors affected by interleukin-2 (IL-2) and transforming growth factor-beta (TGF-β) by protein/DNA arrays using primary NK cells. We found that celastrol, a c-Myb inhibitor, inhibited NK-92 cells more strongly than any other inhibitors of transcription factor candidates. In addition, c-Myb and c-Myb-related signaling molecules, e.g., Nemo-like kinase (NLK) and c-Myc, were regulated by the activation status of NK cells, suggesting that c-Myb is a key regulator of NK cell activity. We also found that celastrol inhibits NK-92-cell-mediated cytotoxicity via the downregulation of NKG2D and granzyme B. Knockdown studies also showed that c-Myb is important for NK cell activation. In particular, the knockdown of c-Myb did not significantly affect NK cell proliferation and survival but decreased the secretion of IFN-γ and the cytotoxicity of NK cells. Our data demonstrate that c-Myb plays a critical role in the activation of NK cells and therefore is a therapeutic target for cancer and viral diseases.

60 APPLIED LIFE SCIENCES↗

Up regulated Tmbim1 activation promotes high fat diet (HFD)-induced cardiomyopathy by enhancement of inflammation and oxidative stress

Highlights: • Tmbim1 deletion exacerbates metabolic syndrome in HFD-fed mice. • Tmbim1 knockout aggravates HFD-induced cardiac inflammation and oxidative stress. • Tmbim1-regulated cardiac injury is tightly associated with inflammation and oxidative stress in PA-treated primary cardiomyocytes. The prevalence of cardiomyopathy due to metabolic stress has up-regulated dramatically; nevertheless, its molecular mechanisms remain unclear. Here we suggested that transmembrane BAX inhibitor motif-containing 1 (Tmbim1) is down-regulated in the hearts of mice fed with high fat diet (HFD). We provided evidence that Tmbim1 knockout (KO) accelerated HFD-induced metabolic disorders in mice, as supported by the remarkable increase of fasting serum glucose and insulin levels. HFD-induced cardiac dysfunctions were greatly intensified by the loss of Tmbim1, along with higher levels of lactate dehydrogenase (LDH) and creatine kinase (CK) in serum. In addition, Tmbim1 deletion significantly enhanced lipid accumulation in heart of mice administrated with HFD. Furthermore, Tmbim1 knockout reinforced myocardial inflammation, evidenced by increasing the expression of pro-inflammatory cytokines (interleukin 1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α)), and the activation of nuclear factor-κB (NF-κB) signaling pathway. Tmbim1 deficiency strengthened oxidative damage in hearts of HFD-fed mice, accompanied with a significant reduction of nuclear factor-erythroid 2 related factor 2 (Nrf-2) pathway. In palmitate (PA)-treated primary cardiomyocytes, Tmbim1 ablation markedly enhanced cell inflammation and oxidative stress, which were abolished by the suppression of ROS generation and NF-κB activation. Taken together, these findings suggested that Tmbim1 might be a key suppressor of metabolic stress-induced cardiomyopathy, which could be a promising target for the treatment of metabolic syndrome-triggered myocardial damage and heart failure.

60 APPLIED LIFE SCIENCES↗

Gulo regulates the proliferation, apoptosis and mesenchymal-to-epithelial transformation of metanephric mesenchyme cells via inhibiting Six2

During kidney development, the balance between self-renewal and differentiation of metanephric mesenchyme (MM) cells, mainly regulated by Sine oculis-related homeobox 2 (Six2), is critical for forming mature kidney. L-gulono-γ-lactone oxidase (Gulo), a crucial enzyme for vitamin C synthesis, reveals a different expression at various stages during kidney development, but its function in the early renal development remains unknown. In this work, we aim to study the role of Gulo in MM cells at two differentiation stages. We found that Gulo expression in undifferentiated MM (mK3) cells was lower than in differentiated MM (mK4) cells. Over-expression of Gulo can promote mesenchymal-to-epithelial transformation (MET) and apoptosis and inhibit the proliferation in mK3 cells. Knock-down of Gulo in mK4 cells made its epithelial character cells unstabilized, facilitated the proliferation and restrained the apoptosis. Furthermore, we found that Six2 was negatively regulated by Gulo, and over-expression or knock-down of Six2 was able to rescue partially the MET, proliferation and apoptosis of MM cells caused by Gulo. In conclusion, these findings reveal that Gulo promotes the MET and apoptosis, and inhibits proliferation in MM cells by down-regulating Six2.

60 APPLIED LIFE SCIENCES↗

GhUMC1, a blue copper-binding protein, regulates lignin synthesis and cotton immune response

Highlights: • Knock-down of GhUMC1 attenuates the cotton immune response. • GhUMC1 has a spatio-temporal regulation in cotton disease resistance. • GhUMC1 acts upstream of lignin synthesis and is involved in cell wall remodeling. Verticillium wilt caused by the soil-borne fungus Verticillium dahliae is a serious problem for the sustainable production of cotton. The mechanism of cotton resistance to V. dahliae is unclear, which makes it is difficult to improve cotton resistance breeding. In this study, we characterized an umecyanin-like gene GhUMC1 in cotton, which is homologous to the AtBCB gene in Arabidopsis. It is predominantly expressed in roots and responds to pathogen infection. Knock-down of GhUMC1 increases plant susceptibility to V. dahliae. Expression levels of genes in the JA and SA signaling pathways in roots were down-regulated in GhUMC1-silenced plants. The transcripts of lignin synthesis genes, such as C4H, HCT, CCoAOMT and CAD, were also decreased in GhUMC1 knock-down seedlings, as was lignin content. Interestingly, knock-down of the GhUMC1 also decreased the contents of H{sub 2}0{sub 2} compared with the control. Our results suggest that GhUMC1 is involved in cotton resistance to V. dahliae by the regulation of the JA signaling pathway and lignin metabolism.

60 APPLIED LIFE SCIENCES↗

Foot-and-mouth disease virus non-structural protein 2B negatively regulates the RLR-mediated IFN-β induction

Highlights: • FMDV 2B is a negatively regulator of type I interferon induction. • FMDV 2B can inhibit the phosphorylation of TBK1 and IRF3. • FMDV 2B inhibited the expression of the RIG-I and MDA5. Foot-and-mouth disease virus (FMDV) is the causative agent of Foot-and-mouth disease (FMD), which is an acute and highly contagious disease affecting pigs, cattle and other cloven-hoofed animals. Several studies have shown that FMDV has evolved multiple strategies to evade the host innate immune response, but the underlying mechanisms for immune evasion are still not fully understood. In the current research, we have demonstrated that FMDV utilizes its non-structural protein 2B to sabotage the host immune response. Over-expression of the FMDV 2B inhibited Poly(I:C)-induced or SeV-triggered up-regulation of IFN-β, IL-6 as well as ISG15. When HEK293T cells were transfected with FMDV 2B, the phosphorylation of TBK1 and IRF3 was inhibited. Co-immunoprecipitation and pull-down experiments indicated that FMDV 2B protein could interact with host RIG-I and MDA5. Moreover, FMDV 2B also inhibited the expression of the RIG-I and MDA5. Thus, FMDV 2B negatively regulates the RLR-mediated IFN-β induction by targeting RIG-I and MDA5.

60 APPLIED LIFE SCIENCES↗

The TORC1–Nem1/Spo7–Pah1/lipin axis regulates microautophagy induction in budding yeast

Highlights: • TORC1 inactivation induces microautophagy in budding yeast. • Loss of Vps27, but not Atg1, Atg7, or Atg8, was required for TORC1 inactivation-induced microautophagy. • The Nem1/Spo7–Pah1 axis was also critical for microautophagy induction. • The TORC1–Nem1/Spo7–Pah1 axis is a master regulator of microautophagy in yeast. Nutrient starvation and inactivation of target of rapamycin complex 1 (TORC1) protein kinase promotes macroautophagy. Macroautophagy is a lipid-consuming process, and Nem1/Spo7 protein phosphatase and Pah1/lipin phosphatidate phosphatase are activated after TORC1 inactivation, supporting macroautophagy induction in the budding yeast Saccharomyces cerevisiae. On the other hand, whether and how microautophagy, which also consumes lipids, is regulated by TORC1 is controversial. Here we show that TORC1 inactivation induces microautophagy in budding yeast. Vps27, but not Atg1, Atg7, or Atg8, was required for TORC1 inactivation-induced microautophagy. Furthermore, the Nem1/Spo7–Pah1 axis was also critical for microautophagy induction. Thus, the TORC1–Nem1/Spo7–Pah1 axis is a master regulator of not only macroautophagy but also microautophagy in budding yeast.

60 APPLIED LIFE SCIENCES↗

Quantitative proteome analysis identifies MAP2K6 as potential regulator of LIFR-induced radioresistance in nasopharyngeal carcinoma cells

Using Tandem Mass Tags (TMT) labeling and LC-MS/MS analysis of peptides from two cell lines (CNE2 and its radioresistant subclone CNE2-IR), we identified 754 proteins differentially expressed in CNE2-IR compared to CNE2. MAP2K6 was identified as a candidate radioresistance-related protein kinase. In vitro functional analysis revealed that over-expression of MAP2K6 significantly enhanced cell survival and colony formation following irradiation in NPC cells. Further, knockdown of MAP2K6 in radioresistant NPC cells led to decreased colony formation and increased apoptotic cells following irradiation. However, the effect of MAP2K6 in regulating the radioresistance in NPC cells did not seem to depend on p38/MAPK activity. Importantly, MAP2K6 might be required for leukemia inhibitory factor receptor (LIFR)-regulated radioresistance, as the expression levels of MAP2K6 affected LIFR/p70S6K signaling activation in NPC cells. Further, MAP2K6 kinase activity is required to activate LIFR/p70S6K signaling and to confer pro-survival effect on NPC cells. In conclusion, MAP2K6 might be an important regulator of LIFR-induced radioresistance in NPC.

60 APPLIED LIFE SCIENCES↗

Cellular fatty acid level regulates the effect of tolylfluanid on mitochondrial dysfunction and insulin sensitivity in C2C12 skeletal myotubes

Highlights: • Tolylfluanid reduced lipid accumulation in skeletal myotubes. • Tolylfluanid-dependent mitochondrial dysfunction is regulated by fatty acid level. • Tolylfluanid regulated insulin signaling in a fatty acid-dependent manner. • Tolylfluanid reduced protein synthesis in high-fatty acid treated skeletal myotubes. Previous research suggests that the endocrine disrupting chemical tolylfluanid (TF) may promote metabolic dysfunction and insulin resistance in humans. The potential impact of TF on skeletal muscle metabolism has yet to be fully investigated. The purpose of this study was to determine whether TF can promote insulin resistance and metabolic dysfunction in mammalian skeletal muscle cells. C2C12 murine skeletal myotubes were exposed to 1 ppm TF for 24 h. To examine the potential effect of cellular fatty acid levels on TF-dependent regulation of mitochondrial metabolism and insulin signaling, we treated skeletal myotubes with 0.25 mM or 1.0 mM oleic acid (OA) during TF exposure trials. Tolylfluanid (1–10 ppm) reduced lipid accumulation by approximately 20% in 0.25 and 1.0 mM OA treated cells. The addition of 0.25 mM OA completely inhibited the TF-dependent reduction in maximal mitochondrial oxygen consumption rate (OCR) while 1.0 mM OA exacerbated the TF-dependent reduction in mitochondrial OCR. Exposing skeletal myotubes to 1 ppm TF promoted an 80% reduction in mitochondrial membrane potential, which was completely inhibited by 0.25 mM OA and partially inhibited by1.0 mM OA. The addition of 0.25 mM OA promoted a TF-dependent increase in insulin-dependent P-Akt (Ser473). In contrast, the addition of 1.0 mM OA promoted a significant reduction in insulin-dependent P-Akt (Ser473). Further, the addition of 1 ppm TF significantly reduced insulin-dependent mTORC1 activity regardless of OA concentration. Finally, TF significantly reduced insulin-dependent protein synthesis in the 1 mM OA treated cells only. Our results demonstrate that the effect of 1 ppm TF on mitochondrial function and insulin-dependent protein synthesis in skeletal myotubes was largely dependent upon cellular fatty acid levels.

60 APPLIED LIFE SCIENCES↗

Long non-coding RNA OGFRP1 regulates LYPD3 expression by sponging miR-124-3p and promotes non-small cell lung cancer progression

Highlights: • The expression levels of lncRNA OGFRP1 was up-regulated in NSCLC tissues and cell lines. • Overexpression of lncRNA OGFRP1 was associated with advanced clinical features and poor prognosis in NSCLC patients. • LncRNA OGFRP1 promoted NSCLC cells proliferation, migration and invasion by regulation of miR-124-3p-LYPD3 pathway. Long noncoding RNA (OGFRP1) has been reported to be involved in the progression of non-small cell lung cancer (NSCLC). However, the expression pattern, functions and molecular mechanisms of OGFRP1 in NSCLC remains unclear. In the present study, we found that OGFRP1 expression was significantly up-regulated in both NSCLC tissues and cell lines, and the upregulation of OGFRP1 expression is a powerful predictor of advanced clinical stage, lymph nodes metastasis and poor prognosis for NSCLC patients. Loss-of-function assay indicated that knockdown of OGFRP1 inhibited proliferation, migration and invasion, and induced apoptosis in vitro. Mechanistically, OGFRP1 could directly bind to miR-124-3p and effectively act as a competing endogenous RNA (ceRNA) for miR-124-3p to promote the expression of the target gene LYPD3. Taken together, OGFRP1 contributed to progression of NSCLC at least partly through upregulating LYPD3 expression by sponging miR-124-3p, indicating that OGFRP1 may be a novel prognostic biomarker and therapeutic target in NSCLC.

60 APPLIED LIFE SCIENCES↗

Sterol regulatory element binding protein-1: Molecular cloning, tissue distribution and gene expression level in response to nutritional regulation in mud crab, Scylla paramamosain

Highlights: • The complete SREBP-1 cDNA sequence was cloned from the hepatopancreas of mud crab based on the RACE technology. • Tissue distribution analysis revealed that SREBP-1 transcripts were widely distributed in various organs, with higher mRNA levels in the eyestalk and cranial ganglia. • The expression level of SREBP-1 mRNA were up-regulated in proportion to the replacement of dietary fish oil with soybean oil. In the present study, SREBP-1 cDNA was cloned from the hepatopancreas of mud crab (Scylla paramamosain) and characterized by performing rapid-amplification of cDNA ends. The 3361bp long full-length cDNA encodes a polypeptide with 1039 amino acids. Tissue distribution analysis revealed that SREBP-1 transcripts were widely distributed in various organs, with higher mRNA levels in the eyestalk and cranial ganglia. Further, expression level of SREBP-1 mRNA were up-regulated in proportion to the replacement of dietary fish oil (FO) with soybean oil (SO). These results may contribute to better understanding of the long-chain polyunsaturated fatty acids (LC-PUFA) biosynthetic pathway and regulation mechanism in mud crab.

60 APPLIED LIFE SCIENCES↗

Targeting ninjurin 2 by miR-764 regulates hydrogen peroxide (H2O2)-induced neuronal cell death

Highlights: • MicroRNA-764 (miR-764) directly regulates ninjurin2 (NINJ2) expression. • Forced overexpression of miR-764 downregulates NINJ2 in human neuronal cells. • miR-764 inhibitor upregulates NINJ2 in human neuronal cells. • NINJ2 downregulation by miR-764 is cytotoxic to human neuronal cells. • NINJ2 overexpression by lentivirus or mir-764 inhibitor protects neuronal cells from H{sub 2}O{sub 2}. Ninjurin 2 (NINJ2) is a novel adhesion molecule expressed in neurons and glial cells. The current study determined if specific microRNA (miRNA) can regulate NINJ2 expression in human neuronal cells. Sequence analysis of NINJ2 mRNA 3′-untranslated region (3′-UTR) revealed that microRNA-764 (miR-764) putatively targets NINJ2. In SH-SY5Y/SK-N-BE neuronal cells and primary human neurons, lentivirus-mediated overexpression of miR-764 conferred significant repression on NINJ2 3′-UTR luciferase activity and downregulation of NINJ2 mRNA/protein. Conversely, transfection of the miR-764 inhibitor increased NINJ2 mRNA and protein expression in the neuronal cells. Function studies show that NINJ2 downregulation by miR-764 induced significant viability reduction and apoptosis in the neuronal cells. Further, CRISPR/Cas9-mediated NINJ2 knockout mimicked and abolished miR-764-induced actions in SH-SY5Y cells. Conversely, lentivirus-mediated NINJ2 overexpression or transfection of miR-764 inhibitor protected neuronal cells from hydrogen peroxide (H{sub 2}O{sub 2})-induced cell death and apoptosis. Collectively, these results show that NINJ2 is a pro-survival factor in human neuronal cells. miR-764 regulates NINJ2 expression and neuron functions.

60 APPLIED LIFE SCIENCES↗

Clotrimazole inhibits the Wnt/β-catenin pathway by activating two eIF2α kinases: The heme-regulated translational inhibitor and the double-stranded RNA-induced protein kinase

Highlights: • A zebrafish phenotypic screening repositioned antifungal azoles to Wnt inhibitors. • Clotrimazole reduces β-catenin levels in a proteasome-independent manner. • Clotrimazole inhibits Wnt/β-catenin signaling by activating eIF2α kinases. The Wnt/β-catenin signaling pathway controls cell proliferation and differentiation, and therefore, when this pathway is excessively activated, it causes tumorigenesis. Our chemical suppressor screening in zebrafish embryos identified antifungal azoles including clotrimazole, miconazole, and itraconazole, as Wnt/β-catenin signaling inhibitors. Here we show the mechanism underlying the Wnt/β-catenin pathway inhibition by antifungal azoles. Clotrimazole reduced β-catenin revels in a proteasome-independent fashion. By gene knockdown of two translational regulators, heme-regulated translational inhibitor and double-stranded RNA-induced protein kinase, we show that they mediate the clotrimazole-induced inhibition of the Wnt/β-catenin pathway. Thus, clotrimazole inhibits the Wnt/β-catenin pathway by decreasing β-catenin protein levels through translational regulation. Antifungal azoles represent genuine candidate compounds for anticancer drugs or chemopreventive agents that reduce adenomatous polyps.

60 APPLIED LIFE SCIENCES↗

The proteomic study of serially passaged human skin fibroblast cells uncovers down-regulation of the chromosome condensin complex proteins involved in replicative senescence

Dermal fibroblast is one of the major constitutive cells of skin and plays a central role in skin senescence. The replicative senescence of fibroblasts may cause skin aging, bad wound healing, skin diseases and even cancer. In this study, a label-free quantitative proteomic approach was employed to analyzing the serial passaged human skin fibroblast (CCD-1079Sk) cells, resulting in 3371 proteins identified. Of which, 280 proteins were significantly changed in early passage (6 passages, P6), middle passage (12 passages, P12) and late passage (21 passages, P21), with a time-dependent decrease or increase tendency. Bioinformatic analysis demonstrated that the chromosome condensin complex, including structural maintenance of chromosomes protein 2 (SMC2) and structural maintenance of chromosomes protein 4 (SMC4), were down-regulated in the serially passaged fibroblast cells. The qRT-PCR and Western Blot experiments confirmed that the expression of these two proteins were significantly down-regulated in a time-dependent manner in the subculture of human skin fibroblasts (HSFb cells). In summary, we used serially passaged human skin fibroblast cells coupled with quantitative proteomic approach to profile the protein expression pattern in the temporal progress of replicative senescence in HSFb cells and revealed that the down-regulation of the chromosome condensin complex subunits, such as SMC2 and SMC4, may play an important role in the fibroblast senescence.

60 APPLIED LIFE SCIENCES↗

Linc01230, transcriptionally regulated by PPARγ, is identified as a novel modifier in endothelial function

Highlights: • Linc01230 expression was reduced by ox-LDL treatment in endothelial cells. • Linc01230 was transcriptionally promoted by PPARγ. • PPARγ directly bound to linc01230 promoter, predicted by bioinformatics and confirmed by ChIP. • Gain-and-loss of functions revealed that linc01230 alleviates ox-LDL-induced endothelial dysfunction. Evidence is growing that PPARγ could improve the bioavailability of NO in pathological conditions to maintain endothelial function by activating Akt/eNOS pathway. LincRNAs participate in regulating development of cardiovascular diseases. Although investigations have been made to delineate the function of PPARγ and lincRNAs, little is known about the regulation relationship between them, especially in endothelial cells. In this study, we not only verified that PPARγ could antagonize the adverse effects brought from ox-LDL, but also found a novel factor related to PPARγ, named linc01230. According to our study, PPARγ transcriptionally regulated linc01230 by specifically combining with two binding regions, which have superposition effect, in the upstream of linc01230 promoter. In addition, linc01230 reduced ox-LDL induced endothelial dysfunction and affected the phosphorylation of Akt. These results conclude linc01230 as a novel modifier in PPARγ–mediated activation of Akt in endothelial function.

60 APPLIED LIFE SCIENCES↗

Physical and biological regulation of neuron regenerative growth and network formation on recombinant dragline silks

In this paper, recombinant spider silks produced in transgenic goat milk were studied as cell culture matrices for neuronal growth. Major ampullate spidroin 1 (MaSp1) supported neuronal growth, axon extension and network connectivity, with cell morphology comparable to the gold standard poly-lysine. In addition, neurons growing on MaSp1 films had increased neural cell adhesion molecule (NCAM) expression at both mRNA and protein levels. The results indicate that MaSp1 films present useful surface charge and substrate stiffness to support the growth of primary rat cortical neurons. Moreover, a putative neuron-specific surface binding sequence GRGGL within MaSp1 may contribute to the biological regulation of neuron growth. These findings indicate that MaSp1 could regulate neuron growth through its physical and biological features. Finally, this dual regulation mode of MaSp1 could provide an alternative strategy for generating functional silk materials for neural tissue engineering.

59 BASIC BIOLOGICAL SCIENCES↗

SHOU4 Proteins Regulate Trafficking of Cellulose Synthase Complexes to the Plasma Membrane

Cell walls play critical roles in plants, regulating tissue mechanics, defining the extent and orientation of cell expansion, and providing a physical barrier against pathogen attack. Cellulose microfibrils, which are synthesized by plasma membrane-localized cellulose synthase (CESA) complexes, are the primary load-bearing elements of plant cell walls. Cell walls are dynamic structures that are regulated in part by cell wall integrity (CWI)-monitoring systems that feed back to modulate wall properties and the synthesis of new wall components. Several receptor-like kinases have been implicated as sensors of CWI, including the FEI1/FEI2 receptor-like kinases. Here, we characterize two genes encoding novel plant-specific plasma membrane proteins (SHOU4 and SHOU4L) that were identified in a suppressor screen of the cellulose-deficient fei1 fei2 mutant. shou4 shou4l double mutants display phenotypes consistent with elevated levels of cellulose, and elevated levels of non-crystalline cellulose are present in this mutant. Disruption of SHOU4 and SHOU4L increases the abundance of CESA proteins at the plasma membrane as a result of enhanced exocytosis. In conclusion, the SHOU4/4L N-terminal cytosolic domains directly interact with CESAs. Our results suggest that the SHOU4 proteins regulate cellulose synthesis in plants by influencing the trafficking of CESA complexes to the cell surface.

09 BIOMASS FUELS↗

An evaluation of a risk-based environmental regulation in Brazil: Limitations to risk management of hazardous installations

The environmental regulation of hazardous projects with risk-based decision-making processes can lead to a deficient management of human exposure to technological hazards. Such an approach for regulation is criticized for simplifying the complexity of decisions involving the economic, social, and environmental aspects of the installation and operation of hazardous facilities in urban areas. Results of a Brazilian case study indicate that oil and gas transmission pipelines may represent a threat to diverse communities if the relationship between such linear projects and human populations is overlooked by regulatory bodies. Results also corroborate known challenges to the implementation of EIA processes and outline limitations to an effective environmental and risk management. Two preliminary topics are discussed to strengthen similar regulatory practices. Firstly, an effective integration between social impact assessment and risk assessment in EIA processes to have a more comprehensive understanding of the social fabric. Secondly, the advancement of traditional management practices for hazardous installations to pursue a strong transition from assessment and evaluation to management and control and to promote an effective interaction between land-use planning and environmental regulation.

54 ENVIRONMENTAL SCIENCES↗