Extended Protein Ions are Formed by the Chain Ejection Model in Chemical Supercharging Electrospray Ionization

Supercharging electrospray ionization can be a powerful tool for increasing charge states in mass spectra and generating unfolded ion structures, yet key details of its mechanism remain unclear. The structures of highly extended protein ions and the mechanism of supercharging were investigated using ion mobility-mass spectrometry. Head-to-tail-linked polyubiquitins (Ubq1−11) were used to determine size and charge state scaling laws for unfolded protein ions formed by supercharging while eliminating amino acid composition as a potential confounding factor. Collisional cross section was found to scale linearly with mass for these ions and several other monomeric proteins, and the maximum observed charge state for each analyte scales with mass in agreement with an analytical charge state scaling law for protein ions with highly extended structures that is supported by experimental gas-phase basicities. These results indicate that these highly unfolded ions can be considered quasi-one-dimensional, and collisional cross sections modeled with the Trajectory Method in Collidoscope show that these ions are significantly more extended than linear α-helices but less extended than straight chains. The effect of internal disulfide bonds on the extent of supercharging was probed using bovine serum albumin, β-lactoglobulin, and lysozyme, each of which contains multiple internal disulfide bonds. Reduction of the disulfide bonds led to a marked increase in charge state upon supercharging without significantly altering folding in solution. This evidence supports a supercharging mechanism in which these proteins unfold before or during evaporation of the electrospray droplet and ionization occurs by the Chain Ejection Model

Evaluation of Implanted Radio Transmitters in Pheasant Chicks

We studied game-farm pheasant (Phasianus colchicus Linneaus) chicks implanted with miniature transmitters to determine if surgery and implantation affected growth, behavior, or survival. Transmitters (weighing 1.2 g) were implanted subcutaneously in the interscapular region in day-old chicks. In Experiment 1, biological effects on chicks with transmitters implanted were compared with data from a control group. In Experiment 2, the effects of anesthesia only, anesthesia with an implanted transmitter, and implanted transmitter only were compared with a control. We measured responses of weight gain, survival, and pecking behavior in each experiment. In Experiment 1, we found no significant differences in weight between chicks with implanted with transmitters versus the control group during 23 days after implantation (repeated-measures ANOVA, n = 34, P = 0.34) in Experiment 1. In Experiment 2, we found overall differences in weight of treated chicks and controls (repeated-measures ANOVA, n = 76, P = 0.02). Chicks in the control group were heavier (P \u3c 0.05) at ages 9, 11, 14, and 21 days but there was no significant differences in weight among treatments and control at 28 days (P = 0.07). Surgery and the presence of implants had no effect on survival or on pecking rates of chicks among groups in either experiment. We failed to reject the hypothesis that surgery and implantation had no effect on growth, behavior, or survival of pheasant chicks

A comprehensive collection of chicken cDNAs

AbstractBirds have played a central role in many biological disciplines, particularly ecology, evolution, and behavior. The chicken, as a model vertebrate, also represents an important experimental system for developmental biologists, immunologists, cell biologists, and geneticists. However, genomic resources for the chicken have lagged behind those for other model organisms, with only 1845 nonredundant full-length chicken cDNA sequences currently deposited in the EMBL databank. We describe a large-scale expressed-sequence-tag (EST) project aimed at gene discovery in chickens (http://www.chick.umist.ac.uk). In total, 339,314 ESTs have been sequenced from 64 cDNA libraries generated from 21 different embryonic and adult tissues. These were clustered and assembled into 85,486 contiguous sequences (contigs). We find that a minimum of 38% of the contigs have orthologs in other organisms and define an upper limit of 13,000 new chicken genes. The remaining contigs may include novel avian specific or rapidly evolving genes. Comparison of the contigs with known chicken genes and orthologs indicates that 30% include cDNAs that contain the start codon and 20% of the contigs represent full-length cDNA sequences. Using this dataset, we estimate that chickens have approximately 35,000 genes in total, suggesting that this number may be a characteristic feature of vertebrates

Mathematicians’ Central Role in Educating the STEM Workforce

In the recent report Engage to Excel,1 President Obama’s Council of Advisors on Science and Technology (PCAST) identifies mathematics as a bottleneck in undergraduate Science, Technology, Engineering, and Mathematics (STEM) education. Among PCAST’s recommendations are ones calling for the development and teaching of college-level mathematics courses “by faculty from mathematics-intensive disciplines other than mathematics” and for “a new pathway for producing K–12 mathematics teachers…in programs in mathematics-intensive fields other than mathematics.”2 While we are in sharp disagreement with these specific recommendations, we do share PCAST’s concern for the state of STEM education. We encourage the mathematics community to focus constructively on the broad view the report sketches. We appeal to the community to amplify its communications with other STEM disciplines, to publicize its teaching innovations, and to redouble its efforts to meet the challenges discussed by PCAST

Aquilegia, Vol. 37 No. 2 - Special Issue, 2013, Newsletter of the Colorado Native Plant Society

https://epublications.regis.edu/aquilegia/1142/thumbnail.jp

Genomic Organization and Evolution of the Vomeronasal Type 2 Receptor-Like (OlfC) Gene Clusters in Atlantic Salmon, Salmo salar

There are three major multigene superfamilies of olfactory receptors (OR, V1R, and V2R) in mammals. The ORs are expressed in the main olfactory organ, whereas the V1Rs and V2Rs are located in the vomeronasal organ. Fish only possess one olfactory organ in each nasal cavity, the olfactory rosette; therefore, it has been proposed that their V2R-like genes be classified as olfactory C family G protein-coupled receptors (OlfC). There are large variations in the sizes of OR gene repertoires. Previous studies have shown that fish have between 12 and 46 functional V2R-like genes, whereas humans have lost all functional V2Rs, and frog sp. have more than 240. Pseudogenization of V2R genes is a prevalent event across species. In the mouse and frog genomes, there are approximately double the number of pseudogenes compared with functional genes. An oligonucleotide probe was designed from a conserved sequence from four Atlantic salmon OlfC genes and used to screen the Atlantic salmon bacterial artificial chromosome (BAC) library. Hybridization-positive BACs were matched to fingerprint contigs, and representative BACs were shotgun cloned and sequenced. We identified 55 OlfC genes. Twenty-nine of the OlfC genes are classified as putatively functional genes and 26 as pseudogenes. The OlfC genes are found in two genomic clusters on chromosomes 9 and 20. Phylogenetic analysis revealed that the OlfC genes could be divided into 10 subfamilies, with nine of these subfamilies corresponding to subfamilies found in other teleosts and one being salmon specific. There is also a large expansion in the number of OlfC genes in one subfamily in Atlantic salmon. Subfamily gene expansions have been identified in other teleosts, and these differences in gene number reflect species-specific evolutionary requirements for olfaction. Total RNA was isolated from the olfactory epithelium and other tissues from a presmolt to examine the expression of the odorant genes. Several of the putative OlfC genes that we identified are expressed only in the olfactory epithelium, consistent with these genes encoding odorant receptors

Prevalence of the HOXB13 G84E prostate cancer risk allele in men treated with radical prostatectomy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106912/1/bju12522.pd

ISGylation drives basal breast tumour progression by promoting EGFR recycling and Akt signalling

ISG15 is an ubiquitin-like modifier that is associated with reduced survival rates in breast cancer patients. The mechanism by which ISG15 achieves this however remains elusive. We demonstrate that modification of Rab GDP-Dissociation Inhibitor Beta (GDI2) by ISG15 (ISGylation) alters endocytic recycling of the EGF receptor (EGFR) in non-interferon stimulated cells using CRISPR-knock out models for ISGylation. By regulating EGFR trafficking, ISGylation enhances EGFR recycling and sustains Akt-signalling. We further show that Akt signalling positively correlates with levels of ISG15 and its E2-ligase in basal breast cancer cohorts, confirming the link between ISGylation and Akt signalling in human tumours. Persistent and enhanced Akt activation explains the more aggressive tumour behaviour observed in human breast cancers. We show that ISGylation can act as a driver of tumour progression rather than merely being a bystander.</p