Genome Snapshot: a new resource at the Saccharomyces Genome Database (SGD) presenting an overview of the Saccharomyces cerevisiae genome

Sequencing and annotation of the entire Saccharomyces cerevisiae genome has made it possible to gain a genome-wide perspective on yeast genes and gene products. To make this information available on an ongoing basis, the Saccharomyces Genome Database (SGD) () has created the Genome Snapshot (). The Genome Snapshot summarizes the current state of knowledge about the genes and chromosomal features of S.cerevisiae. The information is organized into two categories: (i) number of each type of chromosomal feature annotated in the genome and (ii) number and distribution of genes annotated to Gene Ontology terms. Detailed lists are accessible through SGD's Advanced Search tool (), and all the data presented on this page are available from the SGD ftp site ()

Active Site Mutations Change the Cleavage Specificity of Neprilysin

Neprilysin (NEP), a member of the M13 subgroup of the zinc-dependent endopeptidase family is a membrane bound peptidase capable of cleaving a variety of physiological peptides. We have generated a series of neprilysin variants containing mutations at either one of two active site residues, Phe563 and Ser546. Among the mutants studied in detail we observed changes in their activity towards leucine5-enkephalin, insulin B chain, and amyloid β1–40. For example, NEPF563I displayed an increase in preference towards cleaving leucine5-enkephalin relative to insulin B chain, while mutant NEPS546E was less discriminating than neprilysin. Mutants NEPF563L and NEPS546E exhibit different cleavage site preferences than neprilysin with insulin B chain and amyloid ß1–40 as substrates. These data indicate that it is possible to alter the cleavage site specificity of neprilysin opening the way for the development of substrate specific or substrate exclusive forms of the enzyme with enhanced therapeutic potential

Inhibition of nuclear accumulation of phosphorylated ERK by tropomyosin-1-mediated cytoskeletal reorganization

AIM: Most neoplastic cells express diminished levels of tropomyosin (TM) family of actin-binding proteins, which leads to the formation of poorly organized cytoskeleton. The aberrant cytoskeleton is hypothesized to contribute to the neoplastic phenotype through deregulation of intracellular signaling. The aim of the study is to evaluate whether reorganization of cytoskeleton modulates signaling pathways. Methods: We have utilized ras-transformed NIH3T3 (DT) cells and those transduced with TM1 (DT/TM1) as a model system. DT cells are highly malignant whereas the DT/TM1 cells contain reorganized cytoskeleton and exhibit revertant phenotype. Activation status of ras oncogene in DT and DT/TM1 cells was measured by GTP loading. Activation status and subcellular localization of extracellular signal regulated kinase (ERK) was measured in total, cytoplasmic and nuclear compartments by immunoblotting and confocal microscopy. Results: Transduction of TM1 does not alter the activation status of oncogenic ras. Both parental DT and DT/TM1 cells exhibit similar levels of activated ERK in total cellular lysates, whereas DT/TM1 cells contain significantly less phosphorylated ERK pERK) in the nuclear fraction. Disruption of cytosekeletal integrity results in increased nuclear content of pERK, suggesting that tropomyosin-1-induced microfilaments are critical for curtailing the nuclear accumulation of activated ERK, and may contribute to the anti-oncogenic effects of TM1. Conclusion: Our data suggest that spatiotemporal regulation of ERK by cytoskeleton is an important mechanism. Furthermore, aberrant microfilaments, present in neoplastic cells, fail to restrict nuclear localization of ERK, and hence contribute to deregulated ERK signaling. © 2008 MedUnion Press

Chemo-mechanical Caries Removal System- A Brief Review

Chemomechanical caries removal involves the chemicalsoftening of carious dentine followed by its removal by gentleexcavation. Since, its inception in 1980’s, CMCR has been originally marketed as 3 different systems, viz., Caridex, Carisolv® & Papacarie®. Caridex required large volumes of solution and a special applicator tip, which weaned its popularity around 1990’s and thus, was discontinued to be marketed. Carisolv® & Papacarie® were later introduced around 2000, which had overcome the limitations of Caridex and are being used amongst the Clinicians aware of this technique.&nbsp

Association of Social Networks and Physical Activity in South Asians: The Mediators of Atherosclerosis in South Asians Living in America Cohort Study.

BackgroundEliminating racial/ethnic disparities in physical activity remains a challenge in the United States. South Asian immigrants in the United States have particularly low physical activity levels, and evidence suggests that social context may be important. This study examined associations between personal social networks and moderate to vigorous leisure-time physical activity (MVPA) among South Asians in the United States.MethodsWe used cross-sectional data (2014-2017) from 689 South Asians (aged 43-85 y) who participated in the Mediators of Atherosclerosis in South Asians Living in America study. Self-reported physical activity and egocentric network data were collected from participants about their network members. Regression models were used to determine associations between social network characteristics and participants' MVPA.ResultsParticipants were on average 59 years old (SD = 9) and reported 1335 metabolic equivalent minutes per week of MVPA (interquartile range = 735, 2212). Having network members who exercised or who were exercise partners associated with increased MVPA in men (β coefficient = 241 MET min/wk [95% confidence interval, 63 to 419] and β = 520 MET min/wk [95% confidence interval, 322 to 718], respectively). For women, the association was only significant if the exercise partner was a spouse.ConclusionPhysical activity interventions utilizing network members as exercise partners may have potential in South Asians but must consider gender differences