Actin related protein 2/3 complex subunit 1 up-regulation in the hypothalamus prevents high-fat diet induced obesity.

Obesity is a major health crisis in the modern society. Studies have shown that the consumption of a high-fat diet (HFD) induces hypothalamic inflammation and leptin resistance, which consequently favours body mass gain. Actin related protein 2/3 complex subunit 1 (ARPC1B), an actin-binding protein, is highly expressed in immune cells. Recent studies have shown that ARPC1B has a certain anti-inflammatory effect. While ARPC1B expression is decreased in the hypothalamus of mice fed a HFD, the role of ARPC1B in HFD-induced obesity remains unclear. Thus, we investigated whether ARPC1B up-regulation in the hypothalamic arcuate nucleus (ARC) could inhibit the development of obesity. Herein, ARPC1B overexpression lentiviral particles were stereotaxically injected into the ARC of male C57BL/6J mice (7 weeks old) fed with HFD. Overexpression of ARPC1B in the hypothalamic ARC attenuated HFD-induced ARC inflammation, reduced body-weight gain and feed efficiency. Furthermore, up-regulation of ARC ARPC1B improved the glucose tolerance and reduced subcutaneous/epididymal fat mass accumulation, which decreased the serum total cholesterol, serum triglyceride and leptin levels. In addition, upon ARPC1B overexpression in the hypothalamic ARC, intraperitoneal injection of leptin increased the phosphorylation level of signal transducer and activator of transcription 3 (STAT3), an important transcription factor for leptin's action, in the ARC of obese mice. Accordingly, we suggest that up-regulation of ARPC1B in the hypothalamic ARC may improve the HFD-induced hypothalamic inflammation and leptin resistance. Our findings demonstrate that ARPC1B is a promising target for the treatment of diet-induced obesity.

Multiplex Mass Spectrometry Analysis of Amyloid Proteins in Human Plasma for Alzheimer's Disease Diagnosis.

Direct analysis of amyloid proteins in human plasma will promote rapid screening of brain amyloidosis, the earliest pathological signature of Alzheimer's disease. We developed a microflow liquid chromatography-targeted mass spectrometry assay for quantitation of four intact ß-amyloid proteins starting from 1 mL of human plasma samples. This method showed 90% accuracy for predicting brain amyloid using plasma Aß42/Aß40 values from 36 cognitively normal individuals in a prospective clinical study (raw data deposited in MassIVE, Data set ID MSV000087451). Our method may contribute to early diagnosis of Alzheimer's disease.

Proteomic analysis reveals O-GlcNAc modification on proteins with key regulatory functions in Arabidopsis.

Genetic studies have shown essential functions of O-linked N-acetylglucosamine (O-GlcNAc) modification in plants. However, the proteins and sites subject to this posttranslational modification are largely unknown. Here, we report a large-scale proteomic identification of O-GlcNAc-modified proteins and sites in the model plant Arabidopsis thaliana Using lectin weak affinity chromatography to enrich modified peptides, followed by mass spectrometry, we identified 971 O-GlcNAc-modified peptides belonging to 262 proteins. The modified proteins are involved in cellular regulatory processes, including transcription, translation, epigenetic gene regulation, and signal transduction. Many proteins have functions in developmental and physiological processes specific to plants, such as hormone responses and flower development. Mass spectrometric analysis of phosphopeptides from the same samples showed that a large number of peptides could be modified by either O-GlcNAcylation or phosphorylation, but cooccurrence of the two modifications in the same peptide molecule was rare. Our study generates a snapshot of the O-GlcNAc modification landscape in plants, indicating functions in many cellular regulation pathways and providing a powerful resource for further dissecting these functions at the molecular level.

Proteomics and transcriptomics analyses of Arabidopsis floral buds uncover important functions of ARABIDOPSIS SKP1-LIKE1.

BACKGROUND: The ARABIDOPSIS SKP1-LIKE1 (ASK1) protein functions as a subunit of SKP1-CUL1-F-box (SCF) E3 ubiquitin ligases. Previous genetic studies showed that ASK1 plays important roles in Arabidopsis flower development and male meiosis. However, the molecular impact of ASK1-containing SCF E3 ubiquitin ligases (ASK1-E3s) on the floral proteome and transcriptome is unknown. RESULTS: Here we identified proteins that are potentially regulated by ASK1-E3s by comparing floral bud proteomes of wild-type and the ask1 mutant plants. More than 200 proteins were detected in the ask1 mutant but not in wild-type and >300 were detected at higher levels in the ask1 mutant than in wild-type, but their RNA levels were not significantly different between wild-type and ask1 floral buds as shown by transcriptomics analysis, suggesting that they are likely regulated at the protein level by ASK1-E3s. Integrated analyses of floral proteomics and transcriptomics of ask1 and wild-type uncovered several potential aspects of ASK1-E3 functions, including regulation of transcription regulators, kinases, peptidases, and ribosomal proteins, with implications on possible mechanisms of ASK1-E3 functions in floral development. CONCLUSIONS: Our results suggested that ASK1-E3s play important roles in Arabidopsis protein degradation during flower development. This study opens up new possibilities for further functional studies of these candidate E3 substrates.

Multisite light-induced phosphorylation of the transcription factor PIF3 is necessary for both its rapid degradation and concomitant negative feedback modulation of photoreceptor phyB levels in Arabidopsis.

Plants constantly monitor informational light signals using sensory photoreceptors, which include the phytochrome (phy) family (phyA to phyE), and adjust their growth and development accordingly. Following light-induced nuclear translocation, photoactivated phy molecules bind to and induce rapid phosphorylation and degradation of phy-interacting basic Helix Loop Helix (bHLH) transcription factors (PIFs), such as PIF3, thereby regulating the expression of target genes. However, the mechanisms underlying the signal-relay process are still not fully understood. Here, using mass spectrometry, we identify multiple, in vivo, light-induced Ser/Thr phosphorylation sites in PIF3. Using transgenic expression of site-directed mutants of PIF3, we provide evidence that a set of these phosphorylation events acts collectively to trigger rapid degradation of the PIF3 protein in response to initial exposure of dark-grown seedlings to light. In addition, we show that phyB-induced PIF3 phosphorylation is also required for the known negative feedback modulation of phyB levels in prolonged light, potentially through codegradation of phyB and PIF3. This mutually regulatory intermolecular transaction thus provides a mechanism with the dual capacity to promote early, graded, or threshold regulation of the primary, PIF3-controlled transcriptional network in response to initial light exposure, and later, to attenuate global sensitivity to the light signal through reductions in photoreceptor levels upon prolonged exposure.

Influence of preservation temperature on the characteristics of anaerobic ammonium oxidation (anammox) granular sludge.

Preserving active anaerobic ammonium oxidation (anammox) biomass is a potential method for securing sufficient seeding biomass for the rapid start-up of full-scale anammox processes. In this study, anammox granules were cultured in an upflow anaerobic sludge blanket (UASB) reactor (R0), and then the enriched anammox granules were preserved at 35, 20, 4, and -30 °C. The subsequent reactivation characteristics of the granules were evaluated in four UASB reactors (denoted R1, R2, R3, and R4, respectively) to investigate the effect of preservation temperature on the characteristics of anammox granules and their reactivation performance. The results demonstrated that 4 °C was the optimal preservation temperature for maintaining the biomass, activity, settleability, and integrity of the anammox granules and their cellular structures. During the preservation period, a first-order exponential decay model may be used to simulate the decay of anammox biomass and activity. The protein-to-polysaccharide ratio in the extracellular polymeric substances and the heme c content could not effectively indicate the changes in settleability and activity of the anammox granules, respectively, and a loss of bioactivity was positively associated with the degree of anaerobic ammonium-oxidizing bacteria cell lysis. After 42 days of storage, the anammox granules preserved at 4 °C (R3) exhibited a better recovery performance than those preserved at 20 °C (R2), -30 °C (R4), and 35 °C (R1). The comprehensive comparison indicated that 4 °C is the optimal storage temperature for anammox granular sludge because it promotes improved maintenance and recovery performance properties.

Workflow enhancement of TurboID-mediated proximity labeling for SPY signaling network mapping.

TurboID-based proximity labeling coupled to mass spectrometry (PL-MS) has emerged as a powerful tool for mapping protein-protein interactions in both plant and animal systems. Despite advances in sensitivity, PL-MS studies can still suffer from false negatives, especially when dealing with low abundance bait proteins and their transient interactors. Protein-level enrichment for biotinylated proteins is well developed and popular, but direct detection of biotinylated proteins by peptide-level enrichment and the difference in results between direct and indirect detection remain underexplored. To address this gap, we compared and improved enrichment and data analysis methods using TurboID fused to SPY, a low-abundance O-fucose transferase, using an AAL-enriched SPY target library for cross-referencing. Our results showed that MyOne and M280 streptavidin beads significantly outperformed antibody beads for peptide-level enrichment, with M280 performing best. In addition, while a biotin concentration ≤ 50 µM is recommended for protein-level enrichment in plants, higher biotin concentrations can be used for peptide-level enrichment, allowing us to improve detection and data quality. FragPipe's MSFragger protein identification and quantification software outperformed Maxquant and Protein Prospector for SPY interactome enrichment due to its superior detection of biotinylated peptides. Our improved washing protocols for protein-level enrichment mitigated bead collapse issues, improving data quality, and reducing experimental time. We found that the two enrichment methods provided complementary results and identified a total of 160 SPY-TurboID-enriched interactors, including 60 previously identified in the AAL-enriched SPY target list and 100 additional novel interactors. SILIA quantitative proteomics comparing WT and spy-4 mutants showed that SPY affects the protein levels of some of the identified interactors, such as nucleoporin proteins. We expect that our improvement will extend beyond TurboID to benefit other PL systems and hold promise for broader applications in biological research.

SPAG9 is overexpressed in human astrocytoma and promotes cell proliferation and invasion.

Sperm-associated antigen 9 (SPAG9) is a recently characterized oncoprotein involved in the progression of several human malignancies. The present study aims to investigate the expression pattern and biological roles of SPAG9 protein in human astrocytoma. SPAG9 expression was analyzed in 105 astrocytoma specimens by immunohistochemistry. We observed negative staining in normal astrocytes and positive staining of SPAG9 in 63 out of 105 (60 %) astrocytoma samples. Overexpression of SPAG9 correlated with tumor grade (p < 0.001). Small interfering RNA knockdown was performed in U251 and U87 cell lines with relatively high SPAG9 expression. Using methylthiazolyldiphenyl-tetrazolium bromide assay and Matrigel invasion assay, we were able to show that SPAG9 depletion in astrocytoma cell lines inhibited cell proliferation and invasion in both cell lines. In addition, mRNA and protein levels of matrix metallopeptidase 9 (MMP9) were downregulated, while the levels of tissue inhibitor of metalloproteinase 1 (TIMP1) and TIMP2 were not changed, indicating that SPAG9 might regulate invasion through MMP9. In conclusion, SPAG9 serves as an important oncoprotein in human astrocytoma by regulating cell proliferation and invasion.

[Contribution of environmental lead exposure to blood lead level among infants based on IEUBK model].

OBJECTIVE: To evaluate the influence of environmental lead exposure on infant's blood lead through integrated exposure uptake biokinetic model for lead in children (IEUBK) model, based on environmental lead and prenatal lead exposure. METHODS: The data is from a prospective study conducted among pregnant women during 2005 -2007. Blood lead of the pregnant women in the late pregnancy, environmental lead values including lead concentration in soil, air and drink-water were measured. Moreover, the blood lead concentrations of infants were measured as well. RESULTS: Infants were exposed to lead from the pregnant women during the pregnancy, and in the late pregnancy the geometric mean blood lead of pregnant women was (40.3 +/- 3.7) microg/L. The geometric mean blood lead concentration of six-month old infants was (54.7 +/- 6.7) microg/L and there were 17.3% infants whose blood lead concentration were above 100 microg/L. Lead in soil,atmosphere and drink-water were 45.57 mg/kg, 0.023 microg/m3 and 3.25 microg/L respectively. While based on the calculation of the IEUBK model, the value attributed to environmental lead exposure was 12.4 microg/L, accounting for 22.7% of the real blood lead level. CONCLUSION: The results indicated that environmental lead contamination in the rural area might not be the main reason of elevation in blood lead among infants, other lead resources such as food lead exposure might be the major sources for the intake of lead among infants and should be paid more attentions in future.

[Application of the national diagnostic criteria of occupational mercury poisoning].

OBJECTIVE: To investigate the clinical manifestation of patients with renal injury induced by chronic mercury intoxication and the application of the diagnostic criteria of occupational mercury poisoning. METHODS: The clinical data of 8 patients with chronic occupational mercury intoxication were analysed and evaluated. RESULTS: All the observed clinical signs of chronic mercury intoxication correspond with the items of the diagnostic criteria of occupational mercury poisoning. The increasing beta2-MG was one of the clinical manifestations of renal injury induced by chronical mercury intoxication. The renal injury obviously was dose-dependent and reversible. CONCLUSIONS: The national diagnostic criteria of occupational mercury poisoning is practically valuable. The renal injury induced by chronic mercury intoxication should not be neglected.

[Effects of oxidative stress and NF-kappaB levels in peripheral blood mononuclear cells on development of silicosis].

OBJECTIVE: To investigate the change of indicators of oxidative stress in serum and NF-kappaB in peripheral blood mononuclear cells of patients with silicosis, and explore the mechanism of the development of silicosis. METHODS: The subjects were divided into (1) 200 workers exposed to SiO2 for at least 1 years in a foundry served as the dust-exposure group; (2) 130 cases with silicosis (I phase silicosis 64 cases, II phase 46 cases III phase 20 cases) served as the silicosis group; (3) 32 cases with 0+ phase silicosis in the foundry served as the observed group,(4)100 subjects from a hotel served as the control group. The serum including superoxide dismutase (SOD), nitric oxide (NO), serum glutathione peroxidase (GSH-Px), total antioxidant capacity (T-AOC), nitric oxide synthase (NOS), lipid malondialdehyde (MDA) and NF-kappaB protein levels in peripheral blood mononuclear cells were determined, respectively. RESULTS: Compared with the control group, NO levels in dust-exposed group and silicosis group significantly increased, and SOD decreased significantly (P < 0.05 or P < 0.01). Compared with the control group and dust-exposed group, T-AOC, NOS, MDA levels in silicosis group significantly increased (P < 0.05 or P < 0.01). GSH-Px in dust-exposed group and silicosis group were (231.164 +/- 36.484) and (270.469 +/- 39.228)U/ml, respectively which were significantly than that [(223.360 +/- 46.838) U/ml] in control group (P < 0.05 or P < 0.01), and there was significant difference of GSHPx between the silicosis group and the dust-exposed group significantly (P < 0.01) . GSH-Px level [(290.750 +/- 39.129) U/ml] in III phase silicosis group were significantly higher than those [(256.906 +/- 21.41) and (259.594 +/- 34.79) U/ml] in observation group and I phase silicosis group (P < 0.05). NF-kappaB levels [(72.06 +/- 9.12) and (85.25 +/- 11.64) ng/L] in dust-exposed group and silicosis group were significantly higher than that [(59.71 +/- 9.27) ng/L] in control group (P < 0.01), and there was significant difference of between the silicosis group and the dust-exposed group (P < 0.01). There was a positive correlation between serum GSH-Px level and the silicosis stages (r = 0.507, P < 0.01). Also there was a positive correlation between NF-kappaB level and silicosis stages, age, GSH-Px or NO levels (r = 0.376, 0.243, 0.233, 0.221, P < 0.01). CONCLUSION: The imbalance of oxidative and anti-oxidation system and the activation of NF-kappaB are related with the occurrence and development of silicosis. The monitoring of oxidative stress indicators and NF-kappaB is beneficial to the prediction and prognosis assessment of silicosis.

Arabidopsis ACINUS is O-glycosylated and regulates transcription and alternative splicing of regulators of reproductive transitions.

O-GlcNAc modification plays important roles in metabolic regulation of cellular status. Two homologs of O-GlcNAc transferase, SECRET AGENT (SEC) and SPINDLY (SPY), which have O-GlcNAc and O-fucosyl transferase activities, respectively, are essential in Arabidopsis but have largely unknown cellular targets. Here we show that AtACINUS is O-GlcNAcylated and O-fucosylated and mediates regulation of transcription, alternative splicing (AS), and developmental transitions. Knocking-out both AtACINUS and its distant paralog AtPININ causes severe growth defects including dwarfism, delayed seed germination and flowering, and abscisic acid (ABA) hypersensitivity. Transcriptomic and protein-DNA/RNA interaction analyses demonstrate that AtACINUS represses transcription of the flowering repressor FLC and mediates AS of ABH1 and HAB1, two negative regulators of ABA signaling. Proteomic analyses show AtACINUS's O-GlcNAcylation, O-fucosylation, and association with splicing factors, chromatin remodelers, and transcriptional regulators. Some AtACINUS/AtPININ-dependent AS events are altered in the sec and spy mutants, demonstrating a function of O-glycosylation in regulating alternative RNA splicing.

Recombinant expression and biochemical characterization of a novel keratinase BsKER71 from feather degrading bacterium Bacillus subtilis S1-4.

Bacillus subtilis S1-4, isolated from chicken feather could efficiently degrade feathers by secreting several extracellular proteases. In order to get insight into the individual protease involved in keratin hydrolysis, a keratinase designed as BsKER71 was cloned and expressed in Bacillus subtilis WB600. In silico analysis revealed that BsKER71 protein contained a mature protein of 36.1 kDa. Further, purified BsKER71 could hydrolyze a variety of natural proteins, such as fibrous protein, collagen protein, casein, keratin and bovine serum albumin. In addition, this keratinase exhibited high enzyme activity in a wide range of pH and optimal pH of 10.0 and 9.0 in the hydrolysis of casein and keratin, respectively. Similarly, the optimal temperature was 55 °C and 50 °C for the hydrolysis of above two substrates, respectively. The hydrolytic activity was significantly inhibited by phenylmethanesulfonyl fluoride (PMSF), indicating the presence of serine residue in the active site. Moreover, ethylenediaminetetraacetic acid (EDTA) and phenanthroline moderately inhibited the hydrolytic activity. The catalytic activity was stimulated by Mg2+ and Ca2+, but greatly inhibited by Cu2+. Furthermore, several chemicals exhibited different effects on the hydrolysis of casein and keratin by BsKER71. These results provided a better understanding of BsKER71 from feather degrading bacterium B. subtilis S1-4.

Complete Genome Sequence and Characterization of a Polyethylene Biodegradation Strain, Streptomyces Albogriseolus LBX-2.

A bacterial strain, Streptomyces albogriseolus LBX-2, was isolated from a soil sample in Chengdu, China. S. albogriseolus LBX-2 is an aerobic and Gram-positive microorganism that is capable of using the polyethylene as the sole carbon source. Results of scanning electron microscopy and tensile tests indicated that S. albogriseolus LBX-2 could cause the damages to polyethylene (PE). Suspension culture of LBX-2 resulted in the weight loss in the PE powder over a 15-day period. The bacterial growth curve assay clearly demonstrated the utilization of n-hexadecane and n-octadecane for the strain LBX-2. Phylogenetic analysis showed that it was grouped in the same clade as S. albogriseolus belonging to Streptomyces. The complete genome of strain LBX-2 consists of a chromosome of 7,210,477 bp and a linear plasmid of 336,677 bp. Compared with other strains of Streptomyces, the genome size of S. albogriseolus LBX-2 was smaller than the average but its guanine and cytosine content (72.47%) was higher than the others. The Non-Redundant Protein Database (NR), Kyoto Encyclopedia of Genes and Genomes (KEGG), SwissProt, Gene Ontology (GO) and Clusters of Orthologous Groups (COG) annotations provided information on the specific functions of encoded proteins. A total of 21 monooxygenase and 22 dioxygenase genes were found in its genome. Synteny comparison with the genome of Streptomyces coelicolor A3(2) revealed a low overall genetic diversity between them. This study provides valuable information to reveal the underlying mechanisms on PE degradation by S. albogriseolus LBX-2.

Application of chitosan as flocculant for coprecipitation of Mn(II) and suspended solids from dual-alkali FGD regenerating process.

Heavy metals and suspended solid (SS) needed to be removed from the recirculation of dual-alkali flue gas desulfurization (FGD) system. The feasibility of coprecipitation of heavy metal and SS by water-soluble chitosan was studied in a lab scale experiment. The association between chitosan and metal ions was verified through DSC and FT-IR. The pH investigation revealed that at the pH ranged from 5 to 9, there were three stages for different actions: adsorption of chitosan for Mn(II), precipitation of manganese hydroxide and coprecipitation of manganese hydroxide and chitosan-Mn(II) complex. The ion selectivity experiments showed that the occurrence of Ca(II) in the solution had little influence on the adsorption of chitosan for Mn(II). The decrease rate of adsorption capacity was about 0.0023 mmol g(-1) per 1 mg L(-1) Ca(II). When adsorption and flocculation of chitosan occurred at the same time and at the sufficient addition of chitosan, chitosan not only made solids flocculate but also enhanced sorption capacity of chitosan. Application of chitosan for coprecipitation of Mn(II) and SS could remove Mn(II) efficiently and improve the settling characteristics of SS from dual-alkali FGD regenerating process.

Interventions for the Treatment of Craniopharyngioma-Related Hypothalamic Obesity: A Systematic Review.

OBJECTIVE: Craniopharyngiomas (CPs) and their treatment are associated with hypothalamic damage that causes hypothalamic obesity (HO) in 30%-70% of cases. Thus, there is ongoing research regarding tangible solutions for HO, because these patients have unrelenting resistance to basic weight-loss interventions. This review aims to summarize the interventions that are used to treat CP-related HO (CP-HO), including pharmacotherapy and bariatric surgery. METHODS: The Cochrane Library, EMBASE, and PubMed databases were searched up to June 2017 for relevant reports. Two reviewers conducted independent evaluations of the studies identified. RESULTS: Eighteen articles were included in the systematic review, with 3 reports describing pharmacotherapy in randomized controlled trials and 15 reports describing bariatric surgery. Although several studies described effective interventions for treating CP-HO, the evidence base was limited by its low quality and our inability to perform a meta-analysis, which was related to a lack of adequate or integrated data. CONCLUSIONS: Octreotide appears to be a preferred treatment for patients with CP-HO, based on limited data. Gastric bypass surgery may also be suitable for select patients with CP-HO, based on a review of various procedures in this setting. Microsurgical preservation of the hypothalamic structures is mandatory to decrease CP-HO-related morbidity and mortality. Further studies with adequate analytical power and sufficient follow-up are needed to identify effective strategies for CP-HO treatment.

Tbx2 confers poor prognosis in glioblastoma and promotes temozolomide resistance with change of mitochondrial dynamics.

Tbx2 is a cancer-related protein that was found to be overexpressed in several human malignancies. The present study aims to investigate the clinical significance and biological role of Tbx2 in human astrocytoma. We examined its protein expression in 102 cases of astrocytoma tissues using immunohistochemical staining. Negative Tbx2 staining was observed in normal astrocytes, and positive nuclear staining was found in 41 out of 102 astrocytoma specimens. The rate of Tbx2 overexpression in pylocytic astrocytoma, diffuse astrocytoma, anaplastic astrocytoma, and glioblastoma multiform (GBM) were 0%, 26.1%, 40%, and 52%, respectively. Tbx2 overexpression correlated with poor prognosis in patients with astrocytoma or GBM. Tbx2 plasmid transfection was performed in A172 cells, and Tbx2 siRNA knockdown was carried out in U251 cells. Cell Counting Kit-8, cell cycle analysis, and matrigel invasion assay showed that Tbx2 overexpression upregulated cell proliferation, G1-S transition, and invasion, with corresponding change of cyclin D1, p21, and MMP 2 and 9. Importantly, we demonstrated that Tbx2 reduced apoptosis and conferred resistance to temozolomide in GBM cell lines. Further experiments showed that Tbx2 could regulate mitochondrial fission/fusion balance. Western blot showed that Tbx2 overexpression reduced caspase 3 cleavage, while it induced Bcl-2 and p-Drp1 upregulation. In conclusion, our results indicated that Tbx2 might serve as an indicator for poor prognosis and also be useful as an important therapeutic in human GBM, which inhibits apoptosis through regulation of mitochondrial function.

Light-Dependent Degradation of PIF3 by SCFEBF1/2 Promotes a Photomorphogenic Response in Arabidopsis.

Plant seedlings emerging from darkness into the light environment undergo photomorphogenesis, which enables autotrophic growth with optimized morphology and physiology. During this transition, plants must rapidly remove photomorphogenic repressors accumulated in the dark. Among them is PHYTOCHROME-INTERACTING FACTOR 3 (PIF3), a key transcription factor promoting hypocotyl growth. Here we report that, in response to light activation of phytochrome photoreceptors, EIN3-BINDING F BOX PROTEINs (EBFs) 1 and 2 mediate PIF3 protein degradation in a manner dependent on light-induced phosphorylation of PIF3. Whereas PIF3 binds EBFs independent of light, the recruitment of PIF3-EBFs to the core SKP1-CUL1-F box protein (SCF) scaffold is facilitated by light signals or PIF3 phosphorylation. We also found that previously identified LIGHT-RESPONSE BRIC-A-BRACK/TRAMTRACK/BROAD (LRB) E3 ubiquitin ligases target phytochrome B (phyB) and PIF3 primarily under high-light conditions, whereas EBF1/2 vigorously target PIF3 degradation under wide ranges of light intensity without affecting the abundance of phyB. Both genetic and molecular data support that SCFEBF1/2 function as photomorphogenic E3s during seedling development.

Individual and combined inhibition of phenol and thiocyanate on microbial activity of partial nitritation.

This study evaluated the individual and interactive effect of phenol and thiocyanate (SCN-) on partial nitritation (PN) activity using batch test and response surface methodology. The IC50 of phenol and SCN- on PN sludge were 5.6 and 351 mg L-1, respectively. The PN sludge was insensitive to phenol and SCN- at levels lower than 1.77 and 43.3 mg L-1, respectively. A regression model equation was developed and validated to predict the relative specific respiration rate (RSRR) of PN sludge exposed to different phenol and SCN- concentrations. In the range of independent variables, the most severe inhibition was observed with a valley value (17%) for RSRR, when the phenol and SCN- concentrations were 4.08 and 198 mg L-1, respectively. An isobole plot was used to judge the combined toxicity of phenol and SCN-, and the joint inhibitory effect was variable depending on the composition and concentration of the toxic components. Furthermore, the toxic compounds showed independent effects, which is the most common type of combined toxicity.

PPKs mediate direct signal transfer from phytochrome photoreceptors to transcription factor PIF3.

Upon light-induced nuclear translocation, phytochrome (phy) sensory photoreceptors interact with, and induce rapid phosphorylation and consequent ubiquitin-mediated degradation of, transcription factors, called PIFs, thereby regulating target gene expression and plant development. Nevertheless, the biochemical mechanism of phy-induced PIF phosphorylation has remained ill-defined. Here we identify a family of nuclear protein kinases, designated Photoregulatory Protein Kinases (PPK1-4; formerly called MUT9-Like Kinases (MLKs)), that interact with PIF3 and phyB in a light-induced manner in vivo. Genetic analyses demonstrate that the PPKs are collectively necessary for the normal light-induced phosphorylation and degradation of PIF3. PPK1 directly phosphorylates PIF3 in vitro, with a phosphosite pattern that strongly mimics the light-induced pattern in vivo. These data establish that the PPKs are directly involved in catalysing the photoactivated-phy-induced phosphorylation of PIF3 in vivo, and thereby are critical components of a transcriptionally centred signalling hub that pleiotropically regulates plant growth and development in response to multiple signalling pathways.