Selected Grantee Publications
Infection of the Maternal–Fetal Interface and Vertical Transmission Following Low-Dose Inoculation of Pregnant Rhesus Macaques (Macaca mulatta) with an African-Lineage Zika Virus
Koenig et al., PLOS ONE. 2023.
https://doi.org/10.1371/journal.pone.0284964
Researchers examined transmission of Zika virus to nonhuman primate fetuses during pregnancy. Even with a low dosage of inoculation of the dams, the investigators found that the Zika virus infected fetuses, despite the presence of a “placental fortress,” which normally protects fetuses during gestation. This transmission illustrates the high level of infectivity threat that Zika poses, which may increase if mosquitoes expand their global habitats. Understanding how Zika breaches the placental barrier will help researchers develop strategies to prevent fetal infection during pregnancy and thereby prevent adverse outcomes, such as brain malformation defects. Supported by ORIP (P51OD011106, S10OD023526), NIAID, NCI, and NIGMS.
Cell-Type Memory in a Single-Cell Eukaryote Requires the Continuous Presence of a Specific Transcription Regulator
Lee et al., PNAS. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10214202/
Investigators studied the fundamental question and underlying mechanism of how a eukaryotic cell type can be stably maintained through many rounds of DNA replication and cell division in a fungal species where two different cell types (i.e., white and opaque) arise from the same genome. Investigators found that destruction of Wor1, the primary transcription activator of the opaque state, led opaque cells to irreversibly lose their memory and switch to the white-cell state within about 1 hour. This study demonstrates that the continuous presence of Wor1 is needed to maintain the opaque cell state. Data also suggested that a threshold concentration of Wor1 is needed to maintain the opaque state, indicating the importance of the transcription factor in maintaining cell-type memory. Supported by ORIP (S10OD028511), NIAID, and NIGMS.
An E1–E2 Fusion Protein Primes Antiviral Immune Signaling in Bacteria
Ledvina et al., Nature. 2023.
https://www.nature.com/articles/s41586-022-05647-4
Investigators show that the cGAS/DncV–like nucleotidyltransferase (CD‑NTase)–associated protein 2 (Cap2) primes bacterial CD-NTases for activation through a ubiquitin transferase–like mechanism. A cryo-electron microscopy structure of the Cap2-CD-NTase complex reveals Cap2 as an all-in-one ubiquitin transferase–like protein, with distinct domains resembling eukaryotic E1 and E2 proteins. The structure captures a reactive-intermediate state with the CD-NTase C terminus positioned in the Cap2 E1 active site and conjugated to AMP. Cap2 conjugates the CD-NTase C terminus to a target molecule that primes the CD-NTase for increased cGAMP production. The investigators further demonstrate bacteria control immune signaling using an ancient, minimized ubiquitin transferase–like system and provide insight into the evolution of the E1 and E2 machinery across domains of life. Supported by ORIP (S10OD023498, S10OD021527, S10OD025267) and NIGMS.
Resolution of Structural Variation in Diverse Mouse Genomes Reveals Chromatin Remodeling due to Transposable Elements
Ferraj et al., Cell Genomics. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10203049/
Diverse inbred mouse strains are important biomedical research models, yet genome characterization of many strains is fundamentally lacking in comparison with humans. Here, investigators used long-read whole genome sequencing to assemble the genomes of 20 diverse inbred laboratory strains of mice. From whole-genome comparisons, they generated a sequence-resolved callset of 413,758 structural variants. These data are presented as a comprehensive resource that can be used for future genomic studies, aid in modeling and studying the effects of genetic variation, and enhance genotype-to-phenotype research. Supported by ORIP (R24OD021325), NCI, NIGMS, and NHGRI.
Topologically Associating Domain Boundaries Are Required for Normal Genome Function
Rajderkar et al., Communications Biology. 2023.
https://www.nature.com/articles/s42003-023-04819-w
Eukaryotic genomes fold into topologically associating domains (TADs), sub-megabase-scale chromatin segments characterized by high intra-domain chromatin contact frequency. Investigators selected eight independent TAD boundaries in the vicinity of genes active during embryonic development, individually deleted these boundaries from the mouse genome, and systematically examined the consequences on survival, genome organization, gene expression, and development. Results of the studies demonstrate the importance of TAD boundary sequences for in vivo genome function and reinforce the critical need to consider the potential pathogenicity of deletions affecting TAD boundaries in clinical genetics screening. Supported by ORIP (UM1OD023221), NIGMS, and NHGRI.
Identification of a Heterogeneous and Dynamic Ciliome during Embryonic Development and Cell Differentiation
Elliott et al., Development. 2023.
Ciliopathies are a class of diseases that arise when the structure or function of the cilium is compromised. To definitively determine the extent of heterogeneity within the ciliome, investigators compared the ciliomes of six distinct embryonic domains. The data comprehensively revealed that about 30% of the ciliome is differentially expressed across analyzed tissues in the developing embryo. Furthermore, upregulation of numerous ciliary genes correlated with osteogenic cell-fate decisions, suggesting that changes in the ciliome contribute to distinct functions of cell types in vertebrate species. Supported by ORIP (UM1OD023222), NIDCR, and NIGMS.
Cerebrospinal Fluid Protein Markers Indicate Neuro-Damage in SARS-CoV-2-Infected Nonhuman Primates
Maity et al., Molecular & Cellular Proteomics. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9981268/
In this study, researchers examined the proteins expressed in cerebrospinal fluid (CSF) in nonhuman primates (NHPs) to better understand how COVID-19 infection can result in brain pathology, a common outcome. The study found that even in NHPs with minimal or mild COVID‑19, CSF proteins were significantly dysregulated compared with uninfected NHPs. Furthermore, the most affected proteins were enriched in the same brain regions that show lesions after COVID-19 infection, including the cerebral cortex, basal ganglia, and brain stem. Collectively, these regions have wide-ranging control over such crucial functions as cognition, motor control, and breathing, showing how even mild COVID-19 infection can result in significant neurological impairment. Supported by ORIP (P51OD011104, S10OD032453), NIGMS, NCI, and NICHD.
Structural Insights Into the Broad Protection Against H1 Influenza Viruses by a Computationally Optimized Hemagglutinin Vaccine
Dzimianski et al., Communications Biology. 2023.
https://pubmed.ncbi.nlm.nih.gov/37185989/
Influenza is an ongoing public health concern, and computationally optimized broadly reactive antigen (COBRA) hemagglutinin proteins represent a potential strategy for formulating broadly effective influenza vaccines. Researchers determined the crystal structure of COBRA P1, as well as its binding to 1F8, a broadly neutralizing antibody. This work provides valuable insights into the underlying molecular basis for the broad effectiveness of P1, and these insights can be applied to future vaccine designs. Supported by ORIP (K01OD026569), NIAID, and NIGMS.
Anti–Human Immunodeficiency Virus‑1 Activity of MoMo30 Protein Isolated from the Traditional African Medicinal Plant Momordica balsamina
Khan et al., Virology Journal. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10035133/
Momordica balsamina has been reported to produce a ribosome-inactivating protein with anti‑HIV-1 activity and is commonly used by traditional African healers for treatment of HIV. Investigators characterized the mechanism of action of the MoMo30 protein, as well as the sequence of the protein-coding gene. They reported that MoMo30 functions as a lectin or carbohydrate-binding agent (CBA) and inhibits HIV-1 at nanomolar levels, with minimal cellular toxicity at inhibitory levels. CBAs can block the binding of envelope glycoproteins with their target receptors on cells. Thus, this protein could represent a potential new treatment strategy for HIV. Supported by ORIP (R24OD010947), NCI, NIGMS, and NIMHD.
Mechanism of STMN2 Cryptic Splice-Polyadenylation and its Correction for TDP-43 Proteinopathies
Baughn et al., Science. 2023.
Loss of the RNA-binding protein TDP-43 from the nuclei of affected neurons is a hallmark of neurodegeneration in TDP-43 proteinopathies (e.g., amyotrophic lateral sclerosis, frontotemporal dementia). Loss of functional TDP-43 is accompanied by misprocessing of the stathmin-2 (STMN2) RNA precursor. Investigators determined the elements through which TDP‑43 regulates STMN2 pre‑mRNA processing and identified steric binding antisense oligonucleotides that are capable of restoring normal STMN2 protein and RNA levels. This approach is potentially applicable for human therapy. Supported by ORIP (U42OD010921), NIA, NCI, NIGMS, and NINDS.