The complex conformational dynamics of neuronal calcium sensor-1: A single molecule perspective

The human neuronal calcium sensor-1 (NCS-1) is a multispecific two-domain EF-hand protein expressed predominantly in neurons and is a member of the NCS protein family. Structure-function relationships of NCS-1 have been extensively studied showing that conformational dynamics linked to diverse ion-binding is important to its function. NCS-1 transduces Ca 2+ changes in neurons and is linked to a wide range of neuronal functions such as regulation of neurotransmitter release, voltage-gated Ca 2+ channels and neuronal outgrowth. Defective NCS-1 can be deleterious to cells and has been linked to serious neuronal disorders like autism. Here, we review recent studies describing at the single molecule level the structural and mechanistic details of the folding and misfolding processes of the non-myristoylated NCS-1. By manipulating one molecule at a time with optical tweezers, the conformational equilibria of the Ca 2+ -bound, Mg 2+ -bound and apo states of NCS-1 were investigated revealing a complex folding mechanism underlain by a rugged and multidimensional energy landscape. The molecular rearrangements that NCS-1 undergoes to transit from one conformation to another and the energetics of these reactions are tightly regulated by the binding of divalent ions (Ca 2+ and Mg 2+ ) to its EF-hands. At pathologically high Ca 2+ concentrations the protein sometimes follows non-productive misfolding pathways leading to kinetically trapped and potentially harmful misfolded conformations. We discuss the significance of these misfolding events as well as the role of inter-domain interactions in shaping the energy landscape and ultimately the biological function of NCS-1. The conformational equilibria of NCS-1 are also compared to those of calmodulin (CaM) and differences and similarities in the behavior of these proteins are rationalized in terms of structural properties

Evaluation of rough lemon (Citrus jambhiri Lush.)as rootstock for salinity tolerance at seedling stage under in vitro conditions

In vitro approach was adopted to study the effect of salinity on survival and growth of rough lemon (Citrus jambhiri Lush.) seeds. North-West (Punjab) part of India has been facing a major problem of soil salinity for citrus orchards. Therefore, it is logical to study the salinity tolerance of common citrus rootstock, rough lemon (Citrus jambhiri Lush.), grown in the region. The seeds were treated with nine different doses of sodium salt. In all the treatments, leaves of rough lemon seedlings showed severe injury symptoms of chlorosis and necrosis while the seeds cultured in control did not show any injury. There was a significant decrease in seed germination, seedling height, internodal length, and subsequently plant weight with increasing concentration of salt. In contrast to the above characteristics, the length of primary roots increased proportionally with the increase in salt concentration in the culture media. As under stress conditions, the in vitro grown seedlings tend to increase the root length for its survival. In comparison to the control, salt treatments showed increased level of Na+ and Cl- ions in the seedlings and also resulted in a decrease of K+/Na+ ratio. Tolerance index was found minimum (100) in control and maximum in 154mM NaCl treatments after 4 and 8 weeks.Key words: Citrus, salt, sensitivity, chlorosis, sodium chloride

Response of fennel (Foeniculum vulgare) to irrigation and mulching

A field experiment was conducted to find out the effect of irrigation levels and mulching on performance of fennel. Results indicated that application of six irrigations significantly increased the plant height, number of branches plant-1, total chlorophyll content, dry matter accumulation per metre row length, number of umbels plant-1, umbellets umbel-1, seeds umbellet-1 as well as seed, stover and biological yield of fennel compared to four and five irrigations. However, it remained at par with seven irrigations. Results further revealed that application of straw mulch significantly increased number of branches plant-1, dry matter accumulation per metre row length, number of umbellets umbel-1 and yields (seed, stover and biological) over control, dust and plastic mulches. Plant height and number of umbels plant-1 increased significantly with straw mulch as compared to control and dust mulch, but remained at par with plastic mulch. However, in respect of number of seeds umbellet-1, straw, plastic and dust mulch gave similar results. &nbsp

Bell's inequalities in the tomographic representation

The tomographic approach to quantum mechanics is revisited as a direct tool to investigate violation of Bell-like inequalities. Since quantum tomograms are well defined probability distributions, the tomographic approach is emphasized to be the most natural one to compare the predictions of classical and quantum theory. Examples of inequalities for two qubits an two qutrits are considered in the tomographic probability representation of spin states.Comment: 11 pages, comments and references adde

Neurotransmitters Drive Combinatorial Multistate Postsynaptic Density Networks

The mammalian postsynaptic density (PSD) comprises a complex collection of ~1100 proteins. Despite extensive knowledge of individual proteins, the overall organization of the PSD is poorly understood. Here, we define maps of molecular circuitry within the PSD based on phosphorylation of postsynaptic proteins. Activation of a single neurotransmitter receptor, the N-methyl-D-aspartate receptor (NMDAR), changed the phosphorylation status of 127 proteins. Stimulation of ionotropic and metabotropic glutamate receptors and dopamine receptors activated overlapping networks with distinct combinatorial phosphorylation signatures. Using peptide array technology, we identified specific phosphorylation motifs and switching mechanisms responsible for the integration of neurotransmitter receptor pathways and their coordination of multiple substrates in these networks. These combinatorial networks confer high information-processing capacity and functional diversity on synapses, and their elucidation may provide new insights into disease mechanisms and new opportunities for drug discover

Effect of weed and nitrogen management on coriander (Coriandrum sativum L.) yield and economics

Field experiments were carried out during rabi 2007–08 and 2008–09 to evaluate the effect of different weed management measures and nitrogen (N) application on yield and economics of coriander. Results revealed that two hand weedings (HW) at 20 and 40 days after sowing (DAS) produced the highest seed and straw yields (13.71 and 25.83 q ha-1). The highest net returns (Rs. 55841 ha-1) and B : C ratio (2.39) were also obtained under this treatment. However, it was found to be at par with pendimethalin at 1.0 kg ha-1 + HW at 40 DAS, wherein seed and straw yields of 13.61 and 25.57 q ha-1, respectively were obtained. The highest harvest index of 35.01% as well as the lowest mean weed index of 0.7%, were also observed under pendimethalin at 1.0 kg ha-1 + HW at 40 DAS. Results further revealed that application of N at 75 kg ha-1 significantly increased the seed yield to the extent of 11.9%, 32.7% and 84.3% and net returns by Rs. 7915, Rs. 18366 and Rs. 34536 ha-1 over 50, 25 kg N ha-1 and control, respectively. Correlation studies revealed that seed yield of coriander was significantly and positively correlated with growth and yield attributing characters and nutrient uptake by crop. Based on the response studies, 64.75 kg ha-1 was found to be the optimum level of N for coriander. &nbsp

Genetic Variability of Pigeonpea (Cajanus cajan (L.) Millsp.) for Water Logging and Salinity Tolerance under in vitro and in vivo Conditions

Pigeonpea (Cajanus cajan (L.) Millsp.) genotypes acquired from diverse sources, were screened for water logging and salinity tolerance under laboratory and field conditions. Analysis of variance revealed significant differences among the genotypes for various traits. Based on seedling vigor index, six genotypes (AL 1756, AL 1849, AH-06-7, H-2000-14, H-2003-14, ICP 5028) were found highly tolerant, 10 tolerant, 24 moderately tolerant, 12 sensitive and eight highly sensitive to water logging. In case of salinity treatment, seven genotypes (AL 1849, AH-06-7, H-2000-14, H-2001-25, H-2003-14, ICP 5028, JBP 110B) were found tolerant, 14 moderately tolerant, 17 sensitive and 22 highly sensitive. Mean values for germination percentage, seedling length, seedling dry weight and seedling vigor index were generally lower in salinity treatment than water logging treatment. Based on results of laboratory studies, 28 genotypes were screened in pot/field for tolerance to water logging and salinity and were categorized on the basis of plant survival percentage after treatments. Based on plant survival, four genotypes (AL 15, AL 1849, H-2000-14, H-02-28) were found highly tolerant, five tolerant, nine moderately tolerant, four sensitive and six were found highly sensitive in water logging treatment. In case of salinity treatment, six genotypes were found tolerant, five moderately tolerant, three sensitive and 14 were found highly sensitive. Based on higher plant survival (%) under both water logging and saline conditions, common genotypes were identified for their further use in breeding programme

Search for massive rare particles with MACRO

Massive rare particles have been searched for in the penetrating cosmic radiation using the MACRO apparatus at the Gran Sasso National Laboratories. Liquid scintillators, streamer tubes and nuclear track detectors have been used to search for magnetic monopoles (MMs). Based on no observation of such signals, stringent flux limits are established for MMs as slow as a few 10^(-5)c. The methods based on the scintillator and on the nuclear track subdetectors were also applied to search for nuclearites. Preliminary results of the searches for charged Q-balls are also presented.Comment: 20 pages, 9 EPS figures included with epsfi