In vitro and in vivo studies on the structural organization of Chs3 from Saccharomyces cerevisiae

Citation: Gohlke, S., Muthukrishnan, S., & Merzendorfer, H. (2017). In vitro and in vivo studies on the structural organization of Chs3 from Saccharomyces cerevisiae. International Journal of Molecular Sciences, 18(4). doi:10.3390/ijms18040702Chitin biosynthesis in yeast is accomplished by three chitin synthases (Chs) termed Chs1, Chs2 and Chs3, of which the latter accounts for most of the chitin deposited within the cell wall. While the overall structures of Chs1 and Chs2 are similar to those of other chitin synthases from fungi and arthropods, Chs3 lacks some of the C-terminal transmembrane helices raising questions regarding its structure and topology. To fill this gap of knowledge, we performed bioinformatic analyses and protease protection assays that revealed significant information about the catalytic domain, the chitin-translocating channel and the interfacial helices in between. In particular, we identified an amphipathic, crescent-shaped α-helix attached to the inner side of the membrane that presumably controls the channel entrance and a finger helix pushing the polymer into the channel. Evidence has accumulated in the past years that chitin synthases form oligomeric complexes, which may be necessary for the formation of chitin nanofibrils. However, the functional significance for living yeast cells has remained elusive. To test Chs3 oligomerization in vivo, we used bimolecular fluorescence complementation. We detected oligomeric complexes at the bud neck, the lateral plasma membrane, and in membranes of Golgi vesicles, and analyzed their transport route using various trafficking mutants. © 2017 by the authors. Licensee MDPI, Basel, Switzerland

Heat transfer and modelling studies for the analysis of waste storage facilities

Call number: LD2668 .T4 1985 R33Master of Scienc

Efficacy of oral L-arginine on amniotic fluid index in pregnant women with oligohydramnios attending antenatal clinic in a tertiary care hospital in Telangana, India

Background: Oligohydramnios leads to feto-maternal morbidity and mortality. Though there is no specific treatment for oligohydramnios, use of L-arginine seems to be promising. As a nitric oxide donor, it causes vasodilatation, increases placental perfusion and finally increases amniotic fluid. However, data on the use of L-arginine for oligohydramnios is scarce. Hence, this study was aimed to evaluate the efficacy of oral L-arginine on Amniotic Fluid Index (AFI) and to document the pregnancy outcomes in women with oligohydramnios.Methods: This was a prospective observational study conducted on pregnant women attending antenatal clinic (ANC) at Mediciti Institute of Medical Sciences (MIMS), Ghanpur, Telangana, India from 1st January 2018 to 30th June 2018.Results: A total of 50 participants were enrolled and 4 participants among them were lost to follow- up. Mean age (SD) of the women enrolled was 23.3 (3.49) years. Mean gestational age (SD) at the time of diagnosis was 34.61 (1.53) weeks. Mean AFI (SD) at the time of diagnosis and after treatment with L-arginine were 6.8 (1.3) cm and 9.4 (2.82) cm respectively. After a mean treatment duration (SD) of 3.23 (1.38) weeks, a mean (SD) increase of AFI by 2.6 (1.57) cm (P <0.0001) was observed. An increase of AFI was noted in 84.78% of cases (P <0.0001). Mean (SD) Gestational age at the time of delivery was 38.25 (1.48) weeks. Only 37% of participants required operational deliveries. Mean (SD) birth weight of the new borns was 2.54 (0.47) kg. Neonatal Intensive Care Unit (NICU) admissions were required in 32.6% of new borns.Conclusions: L-arginine is efficacious in improving AFI in oligohydramnios. AFI improvement could possibly lead to better neonatal outcomes by reducing preterm deliveries and operative interventions

Safety and efficacy of methyldopa and labetalol in controlling blood pressure in hypertensive disorders of pregnancy

Background: Hypertensive disorders represent the most common medical complication of pregnancy, with a reported incidence of 6-10% and accounts for 15% of maternal mortality. Effective management of pregnancy induced hypertension is vital to improve maternal and foetal outcomes. As data are scarce on comparison of labetolol and methyldopa this study was undertaken. The objective of present study is compare the efficacy and safety of Labetalol versus Methyldopa in the management of Mild to Moderate pregnancy induced hypertension. To evaluate effect of both drugs on maternal and foetal outcomes.Methods: A comparative observational study is designed. 30 patients who received methyldopa and 30 patients who received labetalol were included in the study. Methyldopa was started at a dose of 250-500 mg thrice daily while labetalol was started at a dose of 100-400 mg twice daily. Patients were followed up during antenatal, intrapartum and postpartum period for efficacy, safety, maternal, and perinatal outcomes.Results: Methyldopa and Labetalol reduced mean systolic and mean diastolic blood pressures significantly. safety profile of both drugs was similar. Spontaneous vaginal deliveries were observed more with labetolol significantly.Conclusions: Labetalol is equally efficacious as methyldopa and well tolerated in the treatment of new onset hypertension during pregnancy

Two major cuticular proteins are required for assembly of horizontal laminae and vertical pore canals in rigid cuticle of Tribolium castaneum

The insect exoskeleton is composed of cuticle primarily formed from structural cuticular proteins (CPs) and the polysaccharide chitin. Two CPs, TcCPR27 and TcCPR18, are major proteins present in the elytron (highly sclerotized and pigmented modified forewing) as well as the pronotum (dorsal sclerite of the prothorax) and ventral abdominal cuticle of the red flour beetle, Tribolium castaneum. Both CPs belong to the CPR family, which includes proteins that have an amino acid sequence motif known as the Rebers & Riddiford (R&R) consensus sequence. Injection of double-stranded RNA (dsRNA) for TcCPR27 and TcCPR18 resulted in insects with shorter, wrinkled, warped and less rigid elytra than those from control insects. To gain a more comprehensive understanding of the roles of CPs in cuticle assembly, we analyzed for the precise localization of TcCPR27 and the ultrastructural architecture of cuticle in TcCPR27- and TcCPR18-deficient elytra. Transmission electron microscopic analysis combined with immunodetection using goldlabeled secondary antibody revealed that TcCPR27 is present in dorsal elytral procuticle both in the horizontal laminae and in vertical pore canals. dsRNA-mediated RNA interference (RNAi) of TcCPR27 resulted in abnormal electron-lucent laminae and pore canals in elytra except for the boundary between these two structures in which electron-dense molecule(s) apparently accumulated. Insects subjected to RNAi for TcCPR18 also had disorganized laminae and pore canals in the procuticle of elytra. Similar ultrastructural defects were also observed in other body wall regions with rigid cuticle such as the thorax and legs of adult T. castaneum. TcCPR27 and TcCPR18 are required for proper formation of the horizontal chitinous laminae and vertical pore canals that are critical for formation and stabilization of rigid adult cuticle

Functional specialization among members of knickkopf family of proteins in insect cuticle organization.

Citation: Chaudhari SS, Moussian B, Specht CA, Arakane Y, Kramer KJ, Beeman RW, et al. (2014) Functional Specialization Among Members Of Knickkopf Family Of Proteins In Insect Cuticle Organization. PLoS Genet 10(8): e1004537. doi:10.1371/journal.pgen.1004537Our recent study on the functional analysis of the Knickkopf protein from T. castaneum (TcKnk), indicated a novel role for this protein in protection of chitin from degradation by chitinases. Knk is also required for the laminar organization of chitin in the procuticle. During a bioinformatics search using this protein sequence as the query, we discovered the existence of a small family of three Knk-like genes (including the prototypical TcKnk) in the T. castaneum genome as well as in all insects with completed genome assemblies. The two additional Knk-like genes have been named TcKnk2 and TcKnk3. Further complexity arises as a result of alternative splicing and alternative polyadenylation of transcripts of TcKnk3, leading to the production of three transcripts (and by inference, three proteins) from this gene. These transcripts are named TcKnk3-Full Length (TcKnk3-FL), TcKnk3-5′ and TcKnk3-3′. All three Knk-family genes appear to have essential and non-redundant functions. RNAi for TcKnk led to developmental arrest at every molt, while down-regulation of either TcKnk2 or one of the three TcKnk3 transcripts (TcKnk3-3′) resulted in specific molting arrest only at the pharate adult stage. All three Knk genes appear to influence the total chitin content at the pharate adult stage, but to variable extents. While TcKnk contributes mostly to the stability and laminar organization of chitin in the elytral and body wall procuticles, proteins encoded by TcKnk2 and TcKnk3-3′ transcripts appear to be required for the integrity of the body wall denticles and tracheal taenidia, but not the elytral and body wall procuticles. Thus, the three members of the Knk-family of proteins perform different essential functions in cuticle formation at different developmental stages and in different parts of the insect anatomy

Cuticular protein with a low complexity sequence becomes cross-linked during insect cuticle sclerotization and is required for the adult molt

Citation: Mun, S., Noh, M. Y., Dittmer, N. T., Muthukrishnan, S., Kramer, K. J., Kanost, M. R., & Arakane, Y. (2015). Cuticular protein with a low complexity sequence becomes cross-linked during insect cuticle sclerotization and is required for the adult molt. Scientific Reports, 5, 11. doi:10.1038/srep10484In the insect cuticle, structural proteins (CPs) and the polysaccharide chitin are the major components. It has been hypothesized that CPs are cross-linked to other CPs and possibly to chitin by quinones or quinone methides produced by the laccase2-mediated oxidation of N-acylcatechols. In this study we investigated functions of TcCP30, the third most abundant CP in protein extracts of elytra (wing covers) from Tribolium castaneum adults. The mature TcCP30 protein has a low complexity and highly polar amino acid sequence. TcCP30 is localized with chitin in horizontal laminae and vertically oriented columnar structures in rigid cuticles, but not in soft and membranous cuticles. Immunoblot analysis revealed that TcCP30 undergoes laccase2-mediated cross-linking during cuticle maturation in vivo, a process confirmed in vitro using recombinant rTcCP30. We identified TcCPR27 and TcCPR18, the two most abundant proteins in the elytra, as putative crosslinking partners of TcCP30. RNAi for the TcCP30 gene had no effect on larval and pupal growth and development. However, during adult eclosion, similar to 70% of the adults were unable to shed their exuvium and died. These results support the hypothesis that TcCP30 plays an integral role as a cross-linked structural protein in the formation of lightweight rigid cuticle of the beetle

Phytochemical constituents and biological activities of Erythrina indica

Erythrina indica commonly known as Coral tree has been widely used in Indian traditional medicine for treating common ailments such as asthma, arthritis, diarrhoea, fever, inflammation and leprosy. Certain phytochemical constituents such as: alkaloids, aliphatic fatty acids, alkaloids have also been reported. A wide range of medicinal formulations have been developed from E. indica that exhibit analgesic, antiarthritic, anti-hypertriglyceridemia, anti-inflammatory and muscle relaxing effects. This review summarizes the phytochemical investigations and pharmacological activities of E. indica

Development of resistance in insects to transgenic plants with bacillus thuringiensis Genes: Current status and management strategies

INTRODUCTION There is a continuing need to increase food production as the world population is expected to exceed 6 billion by 2050. In both the developed and undeveloped countries, the cost for achieving production has become too high because of the need to incur costs for controlling insect pests that cause an estimated loss of $10 billion annually...

Ovipositional and feeding preferences of Helicoverpa armigera towards putative transgenic and non-transgenic pigeonpeas

Helicoverpa armigera is the major constraint for pigeonpea production, and therefore, efforts are being made to develop transgenic pigeonpeas with Bt and SBTI genes to minimize the losses due to this pest. The oviposition behavior of H. armigera on transgenic and non-transgenic plants was studied under no-choice, dual-choice, and multi-choice conditions. No differences were observed in the number of eggs laid on the inflorescences of the transgenic pigeonpeas with cry1Ab or SBTI genes and with the non-transgenic plants. In dual-choice feeding tests, there were no differences in leaf damage, larval weights, and the number of larvae between transgenic and non-transgenic plants. The results suggested that transgenic plants have no influence on the oviposition and feeding preferences of H. armiger