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Taha TY, Chen IP, Hayashi JM, Tabata T, Walcott K, Kimmerly GR, Syed AM, Ciling A, Suryawanshi RK, Martin HS, Bach BH, Tsou CL, Montano M, Khalid MM, Sreekumar BK, Renuka Kumar G, Wyman S, Doudna JA, Ott M. Rapid assembly of SARS-CoV-2 genomes reveals attenuation of the Omicron BA.1 variant through NSP6. Nat Commun 2023; 14:2308. [PMID: 37085489 PMCID: PMC10120482 DOI: 10.1038/s41467-023-37787-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 03/31/2023] [Indexed: 04/23/2023] Open
Abstract
Although the SARS-CoV-2 Omicron variant (BA.1) spread rapidly across the world and effectively evaded immune responses, its viral fitness in cell and animal models was reduced. The precise nature of this attenuation remains unknown as generating replication-competent viral genomes is challenging because of the length of the viral genome (~30 kb). Here, we present a plasmid-based viral genome assembly and rescue strategy (pGLUE) that constructs complete infectious viruses or noninfectious subgenomic replicons in a single ligation reaction with >80% efficiency. Fully sequenced replicons and infectious viral stocks can be generated in 1 and 3 weeks, respectively. By testing a series of naturally occurring viruses as well as Delta-Omicron chimeric replicons, we show that Omicron nonstructural protein 6 harbors critical attenuating mutations, which dampen viral RNA replication and reduce lipid droplet consumption. Thus, pGLUE overcomes remaining barriers to broadly study SARS-CoV-2 replication and reveals deficits in nonstructural protein function underlying Omicron attenuation.
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Affiliation(s)
- Taha Y Taha
- Gladstone Institutes, San Francisco, CA, USA.
| | - Irene P Chen
- Gladstone Institutes, San Francisco, CA, USA
- Department of Medicine, University of California, San Francisco, CA, USA
| | | | | | | | | | - Abdullah M Syed
- Gladstone Institutes, San Francisco, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
| | - Alison Ciling
- Gladstone Institutes, San Francisco, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
| | | | - Hannah S Martin
- Gladstone Institutes, San Francisco, CA, USA
- Department of Chemistry, University of California, Berkeley, CA, USA
| | - Bryan H Bach
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
| | | | | | | | | | | | - Stacia Wyman
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
| | - Jennifer A Doudna
- Gladstone Institutes, San Francisco, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, CA, USA
- Department of Chemistry, University of California, Berkeley, CA, USA
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
- Howard Hughes Medical Institute, University of California, Berkeley, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- California Institute for Quantitative Biosciences (QB3), University of California, Berkeley, CA, USA
| | - Melanie Ott
- Gladstone Institutes, San Francisco, CA, USA.
- Department of Medicine, University of California, San Francisco, CA, USA.
- Chan Zuckerberg Biohub - San Francisco, San Francisco, CA, USA.
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Taha TY, Chen IP, Hayashi JM, Tabata T, Walcott K, Kimmerly GR, Syed AM, Ciling A, Suryawanshi RK, Martin HS, Bach BH, Tsou CL, Montano M, Khalid MM, Sreekumar BK, Kumar GR, Wyman S, Doudna JA, Ott M. Rapid assembly of SARS-CoV-2 genomes reveals attenuation of the Omicron BA.1 variant through NSP6. bioRxiv 2023:2023.01.31.525914. [PMID: 36798416 PMCID: PMC9934579 DOI: 10.1101/2023.01.31.525914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Although the SARS-CoV-2 Omicron variant (BA.1) spread rapidly across the world and effectively evaded immune responses, its viral fitness in cell and animal models was reduced. The precise nature of this attenuation remains unknown as generating replication-competent viral genomes is challenging because of the length of the viral genome (30kb). Here, we designed a plasmid-based viral genome assembly and resc ue strategy (pGLUE) that constructs complete infectious viruses or noninfectious subgenomic replicons in a single ligation reaction with >80% efficiency. Fully sequenced replicons and infectious viral stocks can be generated in 1 and 3 weeks, respectively. By testing a series of naturally occurring viruses as well as Delta-Omicron chimeric replicons, we show that Omicron nonstructural protein 6 harbors critical attenuating mutations, which dampen viral RNA replication and reduce lipid droplet consumption. Thus, pGLUE overcomes remaining barriers to broadly study SARS-CoV-2 replication and reveals deficits in nonstructural protein function underlying Omicron attenuation.
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Martin HS, Podolsky KA, Devaraj NK. Probing the Role of Chirality in Phospholipid Membranes. Chembiochem 2021; 22:3148-3157. [PMID: 34227722 DOI: 10.1002/cbic.202100232] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 07/04/2021] [Indexed: 11/09/2022]
Abstract
Nucleotides, amino acids, sugars, and lipids are almost ubiquitously homochiral within individual cells on Earth. While oligonucleotides and proteins exist as one natural chirality throughout the tree of life, two stereoisomers of phospholipids have separately emerged in archaea and bacteria, an evolutionary divergence known as "the lipid divide". Within this review, we focus on the emergence of phospholipid homochirality and compare the stability of synthetic homochiral and heterochiral membranes in vitro. We discuss chemical probes designed to study the stereospecific interactions of lipid membranes in vitro. Overall, we aim to highlight studies that help elucidate the determinants of stereospecific interactions between lipids, peptides, and small molecule ligands. Continued work in understanding the drivers of favorable interactions between chiral molecules and biological membranes will lead to the design of increasingly selective chemical tools for bioorthogonal labeling of lipid membranes and safer membrane-associating pharmaceuticals.
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Affiliation(s)
- Hannah S Martin
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Kira A Podolsky
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
| | - Neal K Devaraj
- Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093, USA
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Franzini L, Rosenthal J, Spears W, Martin HS, Balderas L, Brown M, Milne G, Drutz J, Evans D, Kozinetz C, Oettgen B, Hanson C. Cost-effectiveness of childhood immunization reminder/recall systems in urban private practices. Pediatrics 2000; 106:177-83. [PMID: 10888689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
OBJECTIVE To assess cost and cost-effectiveness of immunization reminder/recall systems in the private sector. METHODS A manual postcard system (mail) was compared with a computer-based telephone system (autodialer) and control. Costs included time costs and the cost of equipment and supplies. The cost per child and the incremental cost of the intervention relative to control were computed. Cost-effectiveness ratios were computed for return visits and for immunizations delivered. RESULTS The average cost per child was $2.28 for the mail group and $1.47 for the autodialer group. The incremental visit cost relative to the control was higher for the mail group ($9.52) than for the autodialer group ($3.48). The autodialer was more cost-effective in delivering immunizations: $4. 06 per extra immunization (autodialer) versus $12.82 (mail). CONCLUSIONS Excluding start-up costs, the autodialer system was most cost-effective. Including autodialer equipment costs, the autodialer system is more cost-effective only for larger practices.
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Affiliation(s)
- L Franzini
- University of Texas Health Science Center at Houston School of Public Health, Houston, Texas
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Anderson RE, Tan WK, Martin HS, Meyer FB. Effects of glucose and PaO2 modulation on cortical intracellular acidosis, NADH redox state, and infarction in the ischemic penumbra. Stroke 1999; 30:160-70. [PMID: 9880405 DOI: 10.1161/01.str.30.1.160] [Citation(s) in RCA: 147] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND AND PURPOSE During focal cerebral ischemia, the ischemic penumbra or border-zone regions of moderate cortical blood flow reductions have a heterogeneous development of intracellular cortical acidosis. This experiment tested the hypotheses that (1) this acidosis is secondary to glucose utilization and (2) this intracellular acidosis leads to recruitment of potentially salvageable tissue into infarction. METHODS Brain pHi, regional cortical blood flow, and NADH redox state were measured by in vivo fluorescent imaging, and infarct volume was assessed by triphenyltetrazolium chloride histology. Thirty fasted rabbits divided into 6 groups of 5 each were subjected to 4 hours of permanent focal ischemia in the presence of hypoglycemia ( approximately 2.8 mmol/L), moderate hyperglycemia ( approximately 11 mmol/L), and severe hyperglycemia (>28 mmol/L) under either normoxia or moderate hypoxia (PaO2 approximately 50 mm Hg). RESULTS Preischemic hyperglycemia led to a more pronounced intracellular acidosis and retardation of NADH regeneration than in the hypoglycemia groups under both normoxia and moderate hypoxia in the ischemic penumbra. For example, 4 hours after ischemia, brain pHi in the severe hyperglycemia/normoxia group measured 6.46, compared with 6.84 in the hypoglycemia/normoxia group (P<0.01), and NADH fluorescence measured 173% compared with 114%. Infarct volume in the severe hyperglycemia/normoxia group measured 35.1+/-6.9% of total hemispheric volume, compared with 13.5+/-4.2% in the hypoglycemia/normoxia group (P<0.01). CONCLUSIONS Hyperglycemia significantly worsened both cortical intracellular brain acidosis and mitochondrial function in the ischemic penumbra. This supports the hypothesis that the evolution of acidosis in the ischemic penumbra is related to glucose utilization. Furthermore, the observation that hypoglycemia significantly decreased infarct size supports the postulate that cortical acidosis leads to recruitment of ischemic penumbra into infarction.
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Affiliation(s)
- R E Anderson
- Thoralf M. Sundt, Jr, Neurosurgical Research Laboratory, Mayo Clinic and Mayo Graduate School of Medicine, Rochester, Minn 55905, USA.
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