抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

The human genome encodes the blueprint of life, but the function of the vast majority of its nearly three billion bases is unknown. The Encyclopedia of DNA Elements (ENCODE) project has systematically mapped regions of transcription, transcription factor association, chromatin structure and histone modification. These data enabled us to assign biochemical functions for 80% of the genome, in particular outside of the well-studied protein-coding regions. Many discovered candidate regulatory elements are physically associated with one another and with expressed genes, providing new insights into the mechanisms of gene regulation. The newly identified elements also show a statistical correspondence to sequence variants linked to human disease, and can thereby guide interpretation of this variation. Overall, the project provides new insights into the organization and regulation of our genes and genome, and is an expansive resource of functional annotations for biomedical research.

/pdf/an-integrated-encyclopedia-of-dna-elements-in-the-human-52ukbi8ats.pdf

An integrated encyclopedia of DNA elements in the human genome

Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

Resolving the molecular details of proteome variation in the different tissues and organs of the human body will greatly increase our knowledge of human biology and disease. Here, we present a map of the human tissue proteome based on an integrated omics approach that involves quantitative transcriptomics at the tissue and organ level, combined with tissue microarray-based immunohistochemistry, to achieve spatial localization of proteins down to the single-cell level. Our tissue-based analysis detected more than 90% of the putative protein-coding genes. We used this approach to explore the human secretome, the membrane proteome, the druggable proteome, the cancer proteome, and the metabolic functions in 32 different tissues and organs. All the data are integrated in an interactive Web-based database that allows exploration of individual proteins, as well as navigation of global expression patterns, in all major tissues and organs in the human body.

Tissue-based map of the human proteome

Bacteria and archaea have evolved adaptive immune defenses, termed clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) systems, that use short RNA to direct degradation of foreign nucleic acids. Here, we engineer the type II bacterial CRISPR system to function with custom guide RNA (gRNA) in human cells. For the endogenous AAVS1 locus, we obtained targeting rates of 10 to 25% in 293T cells, 13 to 8% in K562 cells, and 2 to 4% in induced pluripotent stem cells. We show that this process relies on CRISPR components; is sequence-specific; and, upon simultaneous introduction of multiple gRNAs, can effect multiplex editing of target loci. We also compute a genome-wide resource of ~190 K unique gRNAs targeting ~40.5% of human exons. Our results establish an RNA-guided editing tool for facile, robust, and multiplexable human genome engineering.

/pdf/rna-guided-human-genome-engineering-via-cas9-4eefu2kibr.pdf

RNA-Guided Human Genome Engineering via Cas9

Liquid-liquid phase separation or condensation is a form of macromolecular compartmentalization. Condensates formed by complex coacervation were hypothesized to have played a crucial part during the origin-of-life. In living cells, condensation organizes biomolecules into a wide range of membraneless compartments. Although RNA is a key component of condensation in cells and the central component of the RNA world hypothesis, little is known about what determines RNA accumulation in condensates and how single condensates differ in their RNA composition. Therefore, we developed an approach to read the RNA content from single condensates using high-throughput sequencing. We find that RNAs which are enriched for specific sequence motifs efficiently accumulate in condensates. These motifs show high sequence similarity to short interspersed elements (SINEs). We observed similar results for protein-derived condensates, demonstrating applicability across different in vitro reconstituted membraneless organelles. Thus, our results provide a new inroad to explore the RNA content of phase-separated droplets at single condensate resolution.

/pdf/characterization-of-rna-content-in-individual-phase-2a66ixl1pc.pdf

Characterization of RNA content in individual phase-separated coacervate microdroplets

Pluripotent stem cells from diverse humans offer the potential to study human functional variation in controlled culture environments. A portion of this variation originates from ancient admixture between modern humans and Neandertals, which introduced alleles that left a phenotypic legacy on individual humans today. Here we show that a large repository of human induced pluripotent stem cells (iPSCs) harbors extensive Neandertal DNA, including most known functionally relevant Neandertal alleles present in modern humans. This resource contains Neandertal DNA that contributes to human phenotypes and diseases, encodes hundreds of amino acid changes, and alters gene expression in specific tissues. Human iPSCs thus provide an opportunity to experimentally explore the Neandertal contribution to present-day phenotypes, and potentially study Neandertal traits.

https://www.biorxiv.org/content/biorxiv/early/2018/04/27/309658.full.pdf

Human stem cell resources are an inroad to Neandertal DNA functions

P-POD, the Princeton Protein Orthology Database, classifies proteins from model organisms and medically-important organisms into families of homologs and provides curated evidence from the literature addressing these relationships. The web page for each protein family includes a phylogenetic tree, sequence alignment, and cross-references to disease-related papers from SGD, papers describing complementation experiments, and OMIM gene and disease information.As participants in the Gene Ontology Consortium’s Reference Genome project, we seek to provide a consistent centralized method to identify orthologous proteins. We have expanded P-POD to include the protein complement of the twelve Reference Genomes. In addition, we have added new tools and search options to provide greater depth, breadth, and flexibility. Users may view families from multiple analyses generated by different methods and/or based on different sets of proteins. Using Notung, a software package that uses duplication-loss parsimony to resolve uncertainty in protein family trees, we have improved P-POD’s phylogenetic trees by fitting the protein trees to an established species phylogeny and annotating them with duplications and losses. A Notung applet on the P-POD web site identifies orthologous and paralogous relationships within each family and allows users to perform custom analyses on the phylogenies. These improvements and others make P-POD, in conjunction with the PANTHER database, an ideal tool for predicting the function of new, uncharacterized genes on the basis of their orthologous relationships to characterized ones.All the data in P-POD are freely and publicly available through the web and by downloading the entire database system via the URL "http://ortholog.princeton.edu/". This work is supported by supplemental funds (Kara Dolinski, subcontract PI) to NHGRI grant HG002273 (PIs Judith Blake, Michael Ashburner, J. Michael Cherry and Suzanna Lewis).

Benjamin Vernot

Papers

Characterization of RNA content in individual phase-separated coacervate microdroplets

Human stem cell resources are an inroad to Neandertal DNA functions

P-POD, The Princeton Protein Orthology Database, as a Tool for Identifying Gene Function