{"entity": "researcher", "timestamp": "2026-07-19T18:02:12.426Z", "family": "Laurent", "given": "Timoth\u00e9e", "initials": "T", "orcid": "0000-0003-0174-723X", "affiliations": ["Department of Medical Biochemistry and Biophysics, Ume\u00e5 University, Ume\u00e5, Sweden.", "Molecular Infection Medicine Sweden, Ume\u00e5 University, Ume\u00e5, Sweden.", "Wallenberg Centre for Molecular Medicine, Ume\u00e5 University, Ume\u00e5, Sweden.", "Ume\u00e5 Centre for Microbial Research (UCMR), Ume\u00e5, Sweden."], "links": {"self": {"href": "https://publications.scilifelab.se/researcher/ee7724006da443c8a9af83f04da44482.json"}, "display": {"href": "https://publications.scilifelab.se/researcher/ee7724006da443c8a9af83f04da44482"}}, "publications": [{"entity": "publication", "iuid": "99c5e06fd2724da8867636bcbedde132", "links": {"self": {"href": "https://publications.scilifelab.se/publication/99c5e06fd2724da8867636bcbedde132.json"}, "display": {"href": "https://publications.scilifelab.se/publication/99c5e06fd2724da8867636bcbedde132"}}, "title": "The organization of double-stranded RNA in the chikungunya virus replication organelle.", "authors": [{"family": "Laurent", "given": "Timoth\u00e9e", "initials": "T", "orcid": "0000-0003-0174-723X", "researcher": {"href": "https://publications.scilifelab.se/researcher/ee7724006da443c8a9af83f04da44482.json"}}, {"family": "Carlson", "given": "Lars-Anders", "initials": "L", "orcid": "0000-0003-2342-6488", "researcher": {"href": "https://publications.scilifelab.se/researcher/ba0e366ce21e49b48212bbed5a0a7bd1.json"}}], "type": "journal article", "published": "2023-07-00", "journal": {"title": "PLoS Negl Trop Dis", "issn": "1935-2735", "issn-l": "1935-2727", "volume": "17", "issue": "7", "pages": "e0011404"}, "abstract": "Alphaviruses are mosquito-borne, positive-sense single-stranded RNA viruses. Amongst the alphaviruses, chikungunya virus is notable as a large source of human illness, especially in tropical and subtropical regions. When they invade a cell, alphaviruses generate dedicated organelles for viral genome replication, so-called spherules. Spherules form as outward-facing buds at the plasma membrane, and it has recently been shown that the thin membrane neck that connects this membrane bud with the cytoplasm is guarded by a two-megadalton protein complex that contains all the enzymatic functions necessary for RNA replication. The lumen of the spherules contains a single copy of the negative-strand template RNA, present in a duplex with newly synthesized positive-sense RNA. Less is known about the organization of this double-stranded RNA as compared to the protein components of the spherule. Here, we analyzed cryo-electron tomograms of chikungunya virus spherules in terms of the organization of the double-stranded RNA replication intermediate. We find that the double-stranded RNA has a shortened apparent persistence length as compared to unconstrained double-stranded RNA. Around half of the genome is present in either of five conformations identified by subtomogram classification, each representing a relatively straight segment of ~25-32 nm. Finally, the RNA occupies the spherule lumen at a homogeneous density, but has a preferred orientation to be perpendicular to a vector pointing from the membrane neck towards the spherule center. Taken together, this analysis lays another piece of the puzzle of the highly coordinated alphavirus genome replication.", "doi": "10.1371/journal.pntd.0011404", "pmid": "37406010", "labels": {"Cryo-EM": "Service"}, "xrefs": [{"db": "pmc", "key": "PMC10351700"}, {"db": "pii", "key": "PNTD-D-22-01598"}], "notes": [], "created": "2023-11-27T11:36:27.934Z", "modified": "2023-12-04T10:00:12.240Z"}, {"entity": "publication", "iuid": "ceeb5c507a03477086626e70dd11d9e0", "links": {"self": {"href": "https://publications.scilifelab.se/publication/ceeb5c507a03477086626e70dd11d9e0.json"}, "display": {"href": "https://publications.scilifelab.se/publication/ceeb5c507a03477086626e70dd11d9e0"}}, "title": "Architecture of the chikungunya virus replication organelle.", "authors": [{"family": "Laurent", "given": "Timoth\u00e9e", "initials": "T", "orcid": "0000-0003-0174-723X", "researcher": {"href": "https://publications.scilifelab.se/researcher/ee7724006da443c8a9af83f04da44482.json"}}, {"family": "Kumar", "given": "Pravin", "initials": "P"}, {"family": "Liese", "given": "Susanne", "initials": "S", "orcid": "0000-0001-7420-5488", "researcher": {"href": "https://publications.scilifelab.se/researcher/cb4ed3f41d6946e1a82472041e9a96d6.json"}}, {"family": "Zare", "given": "Farnaz", "initials": "F", "orcid": "0000-0001-5619-8165", "researcher": {"href": "https://publications.scilifelab.se/researcher/d627cd87fe4d4c0f82ac696d5faf289b.json"}}, {"family": "Jonasson", "given": "Mattias", "initials": "M", "orcid": "0000-0001-5528-3405", "researcher": {"href": "https://publications.scilifelab.se/researcher/6956cf58f09c486095fc21819b65884e.json"}}, {"family": "Carlson", "given": "Andreas", "initials": "A", "orcid": "0000-0002-3068-9983", "researcher": {"href": "https://publications.scilifelab.se/researcher/39f4cc3bec4747da984c7c382a8ca5ae.json"}}, {"family": "Carlson", "given": "Lars-Anders", "initials": "LA", "orcid": "0000-0003-2342-6488", "researcher": {"href": "https://publications.scilifelab.se/researcher/ba0e366ce21e49b48212bbed5a0a7bd1.json"}}], "type": "journal article", "published": "2022-10-19", "journal": {"title": "Elife", "issn": "2050-084X", "volume": "11", "issn-l": "2050-084X"}, "abstract": "Alphaviruses are mosquito-borne viruses that cause serious disease in humans and other mammals. Along with its mosquito vector, the Alphavirus chikungunya virus (CHIKV) has spread explosively in the last 20 years, and there is no approved treatment for chikungunya fever. On the plasma membrane of the infected cell, CHIKV generates dedicated organelles for viral RNA replication, so-called spherules. Whereas structures exist for several viral proteins that make up the spherule, the architecture of the full organelle is unknown. Here, we use cryo-electron tomography to image CHIKV spherules in their cellular context. This reveals that the viral protein nsP1 serves as a base for the assembly of a larger protein complex at the neck of the membrane bud. Biochemical assays show that the viral helicase-protease nsP2, while having no membrane affinity on its own, is recruited to membranes by nsP1. The tomograms further reveal that full-sized spherules contain a single copy of the viral genome in double-stranded form. Finally, we present a mathematical model that explains the membrane remodeling of the spherule in terms of the pressure exerted on the membrane by the polymerizing RNA, which provides a good agreement with the experimental data. The energy released by RNA polymerization is found to be sufficient to remodel the membrane to the characteristic spherule shape.", "doi": "10.7554/eLife.83042", "pmid": "36259931", "labels": {"Cryo-EM": "Service"}, "xrefs": [{"db": "pmc", "key": "PMC9633065"}, {"db": "pii", "key": "83042"}], "notes": [], "created": "2022-11-30T08:23:52.427Z", "modified": "2022-11-30T08:24:58.306Z"}]}