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Anita Meier

@anitafmeier.bsky.social
122 followers 173 following 57 posts

Virologist at ETHZ sharing my fascination for viruses

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Anita Meier @anitafmeier.bsky.social · 14/09/2026
For years I've been wondering why I see DNA blobs in the cytosol of HSV-1 infected cells! A new study shows that HSV-1 infections trigger the shedding of nuclear DNA into the cytoplasm possibly through cellular mechanosensing. This blebbing might activate IFN signaling through cGAS.
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Anita Meier @anitafmeier.bsky.social · 03/07/2026
Finally, we show that UL9 mediates intermolecular DNA tethering/ bridging.
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Anita Meier @anitafmeier.bsky.social · 03/07/2026
We also show that UL9-induced loops form rapidly and don't migrate or change size. This indicates tethering of two sites rather than loop extrusion.
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Anita Meier @anitafmeier.bsky.social · 03/07/2026
Kymographs of labelled UL9 clearly demonstrate stable binding to non-origin sequences.
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Anita Meier @anitafmeier.bsky.social · 03/07/2026
However, using force spectroscopy we found that UL9 very efficiently (~55%) introduces large (~300bp) loops in larger DNA templates independent of the origin sequence. ATP binding but not hydrolysis destabilises those loops.
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Anita Meier @anitafmeier.bsky.social · 03/07/2026
Previous papers suggested that UL9 bends the ~70bp origin sequence to mediate strand separation. Using smFRET we indeed found some cases of origin bending but it was very rare (~3%).
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Anita Meier @anitafmeier.bsky.social · 16/06/2026
Rotavirus (RV) is the leading cause of severe childhood diarrhea. To enter the host cell, RV must first activate its spike protein. This occurs when trypsin, a digestive enzyme found in the intestine, cleaves specific regions of the spike protein. Hence, ensuring tissue specificity.
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Anita Meier @anitafmeier.bsky.social · 20/04/2026
Herpes simplex virus type 1 (HSV-1) tightly packages its DNA within the capsid and creates a pressure of ~20 atm that is used to inject the genome into the cell nucleus. Check out this beautiful structure of the capsid and portal vertex:
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Anita Meier @anitafmeier.bsky.social · 27/02/2026
Most viruses rely on the host to provide the entire translation machinery. However, giant viruses have evolved to encode part of the machinery themselves. Latest discovery: mimivirus (APMV) encodes its own initiation factor (vIF4F) and specifically promotes translation of viral mRNA!
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Anita Meier @anitafmeier.bsky.social · 16/01/2026
Studying viruses helps us understand cellular processes: the breakthrough discovery of RNA splicing in 1977 was achieved by studying adenovirus (AdV) biology. They used mRNA/ DNA hybridization and electron microscopy.
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Anita Meier @anitafmeier.bsky.social · 02/12/2025
Some of the weirdest viruses: Multipartite viruses have segmented genomes that are enclosed in different capsids, which are independently transmitted. All segments have to meet in the same host cell for complementation. The evolutionary benefit for this lifestyle is unclear.
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Anita Meier @anitafmeier.bsky.social · 11/11/2025
Zika virus induces nanotube formation 👾 in the host cell to facilitate viral spread. ZIKV even uses them to acquire mitochondria from neighbouring uninfected cells!
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Anita Meier @anitafmeier.bsky.social · 14/08/2025
Epstein-Barr virus encodes a protein called EBNA1, which physically tethers 🤝 the viral DNA to the host chromosome so it doesn't get lost during mitosis. www.cell.com/cell/fulltex...
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Anita Meier @anitafmeier.bsky.social · 27/06/2025
Herpes simplex virus type 1 (HSV-1) infections dramatically change the architecture of the host nucleus. HSV-1 specifically recruits certain host factors (e.g. RNAPII) to promote its replication. HSV-1 actively rewires the human genome! 😲Look at how the host genome gets squeezed!!
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Anita Meier @anitafmeier.bsky.social · 14/06/2025
This is a tupanvirus, ~450nm in diameter ~1.2um in length, clearly one of the giant viruses. It encodes for the most complete translational machinery found in viruses with only the ribosome lacking. Most (non-giant) viruses don't encode any components required for translation. It's so fluffy!! 😱
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Anita Meier @anitafmeier.bsky.social · 11/06/2025
Blows my mind 🤯 that it is possible to capture the structural dynamics of viral capsid contraction by thawing and re-freezing the ice within the electron microscope! Anyone interested in microsecond time-resolved cryo-EM should check out this paper: www.nature.com/articles/s41...
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Anita Meier @anitafmeier.bsky.social · 07/05/2025
Weird virus fact: Bacteriophage 29 (Phi29) uses RNA to help package genomic DNA 🤯. This so-called packaging RNA (pRNA) is an essential part of the packaging motor, which is part of the newly formed viral capsid. Check out the pRNA (pink) in the beautiful structure: www.science.org/doi/10.1126/...
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Anita Meier @anitafmeier.bsky.social · 25/04/2025
Weird virus fact: Adeno-associated viruses (AAV) can only replicate if the same host cell is infected with a helper virus. AAV will remain in the host cell (latently infecting it) until a helper virus such as HSV or AdV comes along. www.mdpi.com/1999-4915/12...
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Anita Meier @anitafmeier.bsky.social · 13/04/2025
Weird virus fact: HIV-1 and other retroviruses hijack cellular tRNA and use it as primer to initiate reverse transcription of their RNA genome. They exploit the same tRNA terminal 3′-OH group used by the host for aminoacylation and peptidyl transfer.
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Anita Meier @anitafmeier.bsky.social · 20/03/2025
Weird virus fact: The SV40 polyomavirus dsDNA genome is wrapped around cellular histones within the viral capsid. Most #viruses don't contain histones in their virions. www.sciencedirect.com/science/arti... Image credit: viralzone.expasy.org/148
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Anita Meier @anitafmeier.bsky.social · 16/03/2025
Weird virus fact: Herpesvirus (HSV-1) assimilates the cellular motor kinesin-1 to travel within the cell. HSV-1 takes it up into the tegument to use it for future infection: www.nature.com/articles/s41...
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