The malaria circumsporozoite protein has two functional domains, each with distinct roles as sporozoites journey from mosquito to mammalian host

Conformational changes influence functional properties of circumsporozoite protein expressed on the surface of Plasmodium sporozoites

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Proceedings of the 3rd Biennial Conference of the Society for Implementation Research Collaboration (SIRC) 2015: advancing efficient methodologies through community partnerships and team science

It is well documented that the majority of adults, children and families in need of evidence-based behavioral health interventionsi do not receive them [1, 2] and that few robust empirically supported methods for implementing evidence-based practices (EBPs) exist. The Society for Implementation Research Collaboration (SIRC) represents a burgeoning effort to advance the innovation and rigor of implementation research and is uniquely focused on bringing together researchers and stakeholders committed to evaluating the implementation of complex evidence-based behavioral health interventions. Through its diverse activities and membership, SIRC aims to foster the promise of implementation research to better serve the behavioral health needs of the population by identifying rigorous, relevant, and efficient strategies that successfully transfer scientific evidence to clinical knowledge for use in real world settings [3]. SIRC began as a National Institute of Mental Health (NIMH)-funded conference series in 2010 (previously titled the “Seattle Implementation Research Conference”; $150,000 USD for 3 conferences in 2011, 2013, and 2015) with the recognition that there were multiple researchers and stakeholdersi working in parallel on innovative implementation science projects in behavioral health, but that formal channels for communicating and collaborating with one another were relatively unavailable. There was a significant need for a forum within which implementation researchers and stakeholders could learn from one another, refine approaches to science and practice, and develop an implementation research agenda using common measures, methods, and research principles to improve both the frequency and quality with which behavioral health treatment implementation is evaluated. SIRC’s membership growth is a testament to this identified need with more than 1000 members from 2011 to the present.ii SIRC’s primary objectives are to: (1) foster communication and collaboration across diverse groups, including implementation researchers, intermediariesi, as well as community stakeholders (SIRC uses the term “EBP champions” for these groups) – and to do so across multiple career levels (e.g., students, early career faculty, established investigators); and (2) enhance and disseminate rigorous measures and methodologies for implementing EBPs and evaluating EBP implementation efforts. These objectives are well aligned with Glasgow and colleagues’ [4] five core tenets deemed critical for advancing implementation science: collaboration, efficiency and speed, rigor and relevance, improved capacity, and cumulative knowledge. SIRC advances these objectives and tenets through in-person conferences, which bring together multidisciplinary implementation researchers and those implementing evidence-based behavioral health interventions in the community to share their work and create professional connections and collaborations

The <i>Plasmodium</i> PHIST and RESA-Like Protein Families of Human and Rodent Malaria Parasites

<div><p>The <i>phist</i> gene family has members identified across the <i>Plasmodium</i> genus, defined by the presence of a domain of roughly 150 amino acids having conserved aromatic residues and an all alpha-helical structure. The family is highly amplified in <i>P</i>. <i>falciparum</i>, with 65 predicted genes in the genome of the 3D7 isolate. In contrast, in the rodent malaria parasite <i>P</i>. <i>berghei</i> 3 genes are identified, one of which is an apparent pseudogene. Transcripts of the <i>P</i>. <i>berghei phist</i> genes are predominant in schizonts, whereas in <i>P</i>. <i>falciparum</i> transcript profiles span different asexual blood stages and gametocytes. We pursued targeted disruption of <i>P</i>. <i>berghei phist</i> genes in order to characterize a simplistic model for the expanded <i>phist</i> gene repertoire in <i>P</i>. <i>falciparum</i>. Unsuccessful attempts to disrupt <i>P</i>. <i>berghei PBANKA_114540</i> suggest that this <i>phist</i> gene is essential, while knockout of <i>phist PBANKA_122900</i> shows an apparent normal progression and non-essential function throughout the life cycle. Epitope-tagging of <i>P</i>. <i>falciparum</i> and <i>P</i>. <i>berghei phist</i> genes confirmed protein export to the erythrocyte cytoplasm and localization with a punctate pattern. Three <i>P</i>. <i>berghei</i> PEXEL/HT-positive exported proteins exhibit at least partial co-localization, in support of a common vesicular compartment in the cytoplasm of erythrocytes infected with rodent malaria parasites.</p></div

Dynamics of malaria infection after inoculation with erythrocytic stage parasites and sporozoites.

<p>Survival curves and daily parasitemia of <b>A)</b> Swiss Webster or <b>B)</b> C57Bl/6 mice injected intravenously with the indicated number of schizonts or mixed asexual stages of <i>P</i>. <i>berghei</i> ANKA wt or PBANKA_122900 KO, respectively. Each group contained 5 mice. The average parasitemia for all mice in each group is plotted. C) Survival curves of Swiss Webster mice injected intravenously with 1,000 sporozoites of <i>P</i>. <i>berghei</i> ANKA wt or PBANKA_122900 KO. Mice were monitored daily and the percentage surviving on each day is plotted. There were 5 mice per group and this experiment was repeated with similar results.</p

Immunolocalization of c-myc epitope-tagged PFE1605w PHIST protein within infected erythrocytes.

<p><b>A</b>) Synchronized parasites were harvested at different time points after Percoll-sorbitol purification, air-dried and fixed with ice-cold methanol. Epitope-tagged proteins were stained with anti-c-myc monoclonal antibodies that were conjugated with FITC. Nuclei were stained with DAPI (blue). The abbreviations used to describe parasite stages are as follows: 22 h, late ring stage; 30 h, early-trophozoite stage; 42 h, mid-trophozoite stage; 48 h, late trophozoite stage; and schizont stage. <b>B)</b> Co-localization was assayed using rabbit polyclonal SBP1 followed by goat anti-rabbit IgG conjugated with Alexa 594 (red). <b>C)</b> The pattern of expression of c-myc epitope-tagged PFE1605w PHIST protein is dependent on the fixation protocol. When infected erythrocytes are fixed in solution with 1% paraformaldehyde, 0.075% glutaraldehyde, then PHIST protein shows a broader punctate expression than the Maurer’s cleft marker, SPB1.</p

Transcript expression analysis of <i>phist</i> and <i>resa-like</i> genes in 4 <i>P</i>. <i>falciparum</i> isolates.

<p>The transcript levels of select <i>phist</i> and <i>resa-like</i> genes in 4 isolates of <i>P</i>. <i>falciparum</i>, NF54, Dd2, HB3 and IT4, were compared by real time PCR using cDNA prepared from late schizont stage parasites. Transcript expression was normalized to the expression of the control gene <i>arginyl tRNA synthetase</i> (<i>PFL0900c</i>). In the schematic depiction of <i>phist</i> and <i>resa-like</i> genes, yellow represents the signal sequence, and red represents the PEXEL/HT motif.</p

Immunolocalization of <i>P</i>. <i>berghei</i> PHIST proteins PBANKA_114540, PBANKA_122900, and IBIS within infected erythrocytes.

<p><b>A</b>) PBANKA_114540 co-localizes with PBANKA_122900 within erythrocyte cytoplasmic vesicles. Co-localization was assayed using rabbit polyclonal anti-PBANKA_114540 followed by goat anti-rabbit IgG conjugated with Alexa 488 (green), followed by rabbit polyclonal anti-PBANKA_122900 followed by goat anti-rabbit Alexa 595 (red). Nuclei were stained with DAPI (blue). Control experiments using secondary antibodies were negative. <b>B</b>) Co-localization of mCherry-tagged IBIS protein PBANKA_136550 with the PHIST protein PBANKA_122900 in fixed erythrocytes, by staining with rabbit polyclonal anti-PBANKA_122900 followed by goat anti-rabbit IgG conjugated with Alexa 488. Parasite nuclei were stained with Hoechst (blue). Both proteins partially co-localize inside vesicles in the erythrocyte cytoplasm.</p

Transcript expression analysis of <i>phist</i> and <i>resa-like</i> genes during <i>P</i>. <i>falciparum</i> intraerythrocytic stages.

<p>Gene-specific transcript levels for select <i>phist</i> genes <b>A</b>) and for the <i>resa-like</i> genes <b>B</b>) were analyzed by real time PCR using cDNA prepared from intraerythrocytic synchronized asexual and gametocyte <i>P</i>. <i>falciparum</i> cultures. Note that <i>resa</i> (<i>PFA0110w</i>) and <i>resa2</i> (<i>PF11_0509</i>) are highly expressed relative to the other <i>resa-like</i> genes. Transcript expression was normalized to the expression of the control gene <i>arginyl tRNA synthetase</i> (<i>PFL0900c</i>). Hours post-synchronization indicate time in hours after adding purified schizonts to fresh blood culture. In the schematic depiction of <i>phist</i> and <i>resa-like</i> genes, yellow represents the signal sequence, and red represents the PEXEL/HT motif. The life cycle stage percentage in the population for each time point is shown in <b>C</b>). The letter “G” indicates mature gametocytes.</p