Plasma Proteome Database as a resource for proteomics research

Plasma is one of the best studied compartments in the human body and serves as an ideal body fluid for the diagnosis of diseases. This report provides a detailed functional annotation of all the plasma proteins identified to date. In all, gene products encoded by 3778 distinct genes were annotated based on proteins previously published in the literature as plasma proteins and the identification of multiple peptides from proteins under HUPO's Plasma Proteome Project. Our analysis revealed that 51% of these genes encoded more than one protein isoform. All single nucleotide polymorphisms involving protein-coding regions were mapped onto the protein sequences. We found a number of examples of isoform-specific subcellular localization as well as tissue expression. This database is an attempt at comprehensive annotation of a complex subproteome and is available on the web at http://www.plasmaproteomedatabase.org.     

Molecular characterization of AmiC,a positive regulator in acetamidase operon of <Emphasis Type="Italic">Mycobacterium smegmatis</Emphasis>

Mycobacterium smegmatis, a rapidly growing non-pathogenic mycobacterium, is currently used as a model organism to study mycobacterial genetics. Acetamidase of M. smegmatis is the highly inducible enzyme of Mycobacteria, which utilizes several amide compounds as sole carbon and nitrogen sources. The acetamidase operon has a complex regulatory mechanism, which involves three regulatory proteins, four promoters, and three operator elements. In our previous study, we showed that over-expression of AmiA leads to a negative regulation of acetamidase by blocking the P2 promoter. In this study, we have identified a new positive regulatory protein, AmiC that interacts with AmiA through protein-protein interaction. Gel mobility shift assay showed that AmiC protein inhibits AmiA from binding to the P2 promoter. Interaction of AmiC with cis-acting elements identified its binding ability to multiple regulatory regions of the operon such as P3, OP3, and P1 promoter/operator. Consequently, the addition of inducer acetamide to AmiC complexe trips the complexes, causing AmiC to appear to be the sensory protein for the amides. Homology modeling and molecular docking studies suggest AmiC as a member of Periplasmic binding proteins, which preferentially bind to the inducers and not to the suppressor. Over-expression of AmiC leads to down-regulation of the negative regulator, amiA, and constitutive up-regulation of acetamidase. Based on these findings, we conclude that AmiC positively regulates the acetamidase operon.     

Fragment-based discovery of a potent NAMPT inhibitor

NAMPT expression is elevated in many cancers, making this protein a potential target for anticancer therapy. We have carried out both NMR based and TR-FRET based fragment screens against human NAMPT and identified six novel binders with a range of potencies. Co-crystal structures were obtained for two of the fragments bound to NAMPT while for the other four fragments force-field driven docking was employed to generate a bound pose. Based on structural insights arising from comparison of the bound fragment poses to that of bound FK866 we were able to synthetically elaborate one of the fragments into a potent NAMPT inhibitor.     

Morphogenesis and plant regeneration from tissue cultures of Jatropha curcas

Techniques for the regeneration of Jatropha curcas L. from various explants have been developed. Regeneration from hypocotyl, petiole and leaf explants was evaluated on a range of concentrations of zeatin, kinetin and N⁶ benzyladenine (BA) either singly or in combination with indole-3-butyric acid (IBA). Higher regeneration from hypocotyl and petiole explants was obtained on BA with IBA than on zeatin- or kinetin-supplemented media. Leaf discs from the third expanding leaf exhibited higher regeneration potential than those from the fourth leaf. Independent of the explant type, direct adventitious shoot bud induction was recorded highest on MS medium with 2.22 M BA and 4.9 M IBA. Although the same BA concentration but with reduced IBA concentration (0.49 M) proved effective in callus mediated regeneration from hypocotyl and leaf explants, the petioles required lower concentrations of the two growth regulators (0.44 M BA and 0.49 M IBA). Regenerated shoots could be rooted on growth regulator-free gelled full-strength MS medium. Following simple hardening procedures, the in vitro-raised plants could be transferred to soil and grown to maturity in the field.Abbreviations BA N⁶ benzyladenine - IAA indole-3-acetic acid - IBA indole-3-butyric acid - MS Murashige & Skoog's (1962) medium - NAA -naphthaleneacetic acid     

Patterns of differentiation and hybridization in North American wolflike canids, revealed by analysis of microsatellite loci

Genetic divergence and gene flow among closely related populations are difficult to measure because mutation rates of most nuclear loci are so low that new mutations have not had sufficient time to appear and become fixed. Microsatellite loci are repeat arrays of simple sequences that have high mutation rates and are abundant in the eukaryotic genome. Large population samples can be screened for variation by using the polymerase chain reaction and polyacrylamide gel electrophoresis to separate alleles. We analyzed 10 microsatellite loci to quantify genetic differentiation and hybridization in three species of North American wolflike canids. We expected to find a pattern of genetic differentiation by distance to exist among wolflike canid populations, because of the finite dispersal distances of individuals. Moreover, we predicted that, because wolflike canids are highly mobile, hybrid zones may be more extensive and show substantial changes in allele frequency, relative to nonhybridizing populations. We demonstrate that wolves and coyotes do not show a pattern of genetic differentiation by distance. Genetic subdivision in coyotes, as measured by theta and Gst, is not significantly different from zero, reflecting persistent gene flow among newly established populations. However, gray wolves show significant subdivision that may be either due to drift in past Ice Age refugia populations or a result of other causes. Finally, in areas where gray wolves and coyotes hybridize, allele frequencies of gray wolves are affected, but those of coyotes are not. Past hybridization between the two species in the south-central United States may account for the origin of the red wolf.      

Occurrence of a <Emphasis Type="Italic">Pempheris flavicycla</Emphasis><Emphasis Type="Underline">in</Emphasis> Chennai Coast,India

The sweeper fish Pempheris flavicycla is recorded from Kasimedu fish landing center, Chennai, India, for the first time.     

Identification of two novel cerebrospinal fluid proteins in non specific mental retardation

Cerebrospinal fluid (CSF) from twenty three patients with non specific mental retardation and fourteen age matched normal samples was subjected for qualitative analysis of protein profiles by two-dimensional gel electrophoresis (2-DE) and the proteins were visualised by ultra sensitive silver staining. Two proteins designated as mental retardation associated proteins (MRAP-I and MRAP-II) were identified in six male patients out of twenty three patients CSF samples. MRAP-I had an isoelectric point of 7.4 with a relative molecular weight 16.5 kDa, while MRAP-II had an iso-electric point of 7.2 with a relative molecular weight 16.8 kDa. The two proteins are presumed to be originated from brain, as they could not be traced in the serum of patients, nor due to proteolytic degradation. Despite unknown origin and identity, their presence in the CSF of a specific group of mentally retarded male patients suggest their possible clinical utility and to define protein alterations in mental retardation.