Faculty Opinions recommendation of Export of a Toxoplasma gondii rhoptry neck protein complex at the host cell membrane to form the moving junction during invasion.

White spot syndrome virus (WSSV) is a large enveloped virus which has caused severe mortality and huge economic losses in the shrimp farming industry. The enveloped virus must be combined with the receptors of the host cell membrane by the virus envelope proteins. In the case of WSSV, binding of envelope proteins with receptors of the host cell membrane was discovered in a number of previous studies, such as VP53A and 10 other proteins with chitin-binding protein (CBP), VP28 with Penaeus monodon Rab7, VP187 with β-integrin, and so on. WSSV envelope proteins were also considered capable of forming a protein complex dubbed an ‘infectome’. In this study, the research was focused on the role of CBP in the WSSV infection process, and the relationship between CBP and the envelope proteins VP24, VP28, VP31, VP32 VP39B, VP53A and VP56. The results of the reverse transcription-PCR analyses showed that CBP existed in a variety of shrimp. The speed of WSSV infection could be slowed down by inhibiting CBP gene expression. Far-Western blot analysis and His pull-down assays were conducted, and a protein complex was found that appeared to be composed of a ‘linker’ protein consisting of VP31, VP32 and VP39B together with four envelope proteins, including VP24, VP28, VP53A and VP56. This protein complex was possibly another part of the infectome and the possible binding region with CBP. The findings of this study may have identified certain points for further WSSV research.

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A host cell membrane microdomain is a critical factor for organelle discharge by Toxoplasma gondii

Parasitology International ◽

10.1016/j.parint.2016.05.012 ◽

2016 ◽

Vol 65 (5) ◽

pp. 378-388 ◽

Cited By ~ 5

Author(s):

Michiru Tahara ◽

Syed Bilal Ahmad Andrabi ◽

Ryuma Matsubara ◽

Hiroka Aonuma ◽

Kisaburo Nagamune

Keyword(s):

Toxoplasma Gondii ◽

Cell Membrane ◽

Host Cell ◽

Critical Factor ◽

Host Cell Membrane ◽

Membrane Microdomain

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Three-Dimensional Imaging of Toxoplasma gondii–Host Cell Interactions within the Parasitophorous Vacuole

Microscopy and Microanalysis ◽

10.1017/s143192760404084x ◽

2004 ◽

Vol 10 (5) ◽

pp. 580-585 ◽

Cited By ~ 17

Author(s):

Heide Schatten ◽

Hans Ris

Keyword(s):

Toxoplasma Gondii ◽

Cell Membrane ◽

Host Cell ◽

Parasitophorous Vacuole ◽

Three Dimensional ◽

Host Cells ◽

Preparation Technique ◽

Host Cell Membrane ◽

Three Dimensional Imaging ◽

Structural Interactions

The protozoan parasite Toxoplasma gondii is a representative of apicomplexan parasites that invades host cells through an unconventional motility mechanism. During host cell invasion it forms a specialized membrane-surrounded compartment that is called the parasitophorous vacuole. The interactions between the host cell and parasite membranes are complex and recent studies have revealed in more detail that both the host cell and the parasite membrane contribute to the formation of the parasitophorous vacuole. By using our a new specimen preparation technique that allows three-dimensional imaging of thick-sectioned internal cell structures with high-resolution, low-voltage field emission scanning electron microscopy, we were able to visualize continuous structural interactions of the host cell membrane with the parasite within the parasitophorous vacuole. Fibrous and tubular material extends from the host cell membrane and is connected to parasite membrane components. Shorter protrusions are also elaborated from the parasite. Several of these shorter fine protrusions connect to the fibrous material of the host cell membrane. The elaborate network may be used for modifications of the parasitophorous vacuole membrane that will allow utilization of nutrients from the host cell by the parisite while it is being protected from host cell attacks. The structural interactions between parasite and host cells undergo time-dependent changes, and a fission pore is the most prominent structure left connecting the parasite with the host cell. The fission pore is anchored in the host cell by thick structural components of unknown nature. The new information gained with this technique includes structural details of fibrous and tubular material that is continuous between the parasite and host cell and can be imaged in three dimensions. We present this technique as a tool to investigate more fully the complex structural interactions of the host cell and the parasite residing in the parasitophorous vacuole.

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Faculty Opinions recommendation of The Bacillus subtilis quorum-sensing molecule CSF contributes to intestinal homeostasis via OCTN2, a host cell membrane transporter.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1087414.541922 ◽

2007 ◽

Author(s):

June Kwon-Chung

Keyword(s):

Bacillus Subtilis ◽

Quorum Sensing ◽

Cell Membrane ◽

Host Cell ◽

Membrane Transporter ◽

Intestinal Homeostasis ◽

Host Cell Membrane ◽

Quorum Sensing Molecule

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Exaptation of Retroviral Syncytin for Development of Syncytialized Placenta, Its Limited Homology to the SARS-CoV-2 Spike Protein and Arguments against Disturbing Narrative in the Context of COVID-19 Vaccination

Biology ◽

10.3390/biology10030238 ◽

2021 ◽

Vol 10 (3) ◽

pp. 238

Author(s):

Malgorzata Kloc ◽

Ahmed Uosef ◽

Jacek Z. Kubiak ◽

Rafik M. Ghobrial

Keyword(s):

Cell Membrane ◽

Host Cell ◽

Envelope Glycoprotein ◽

Mammalian Species ◽

Viral Envelope ◽

Spike Protein ◽

Mammalian Evolution ◽

Trophoblast Cells ◽

Host Cell Membrane ◽

Uterine Endometrium

Human placenta formation relies on the interaction between fused trophoblast cells of the embryo with uterine endometrium. The fusion between trophoblast cells, first into cytotrophoblast and then into syncytiotrophoblast, is facilitated by the fusogenic protein syncytin. Syncytin derives from an envelope glycoprotein (ENV) of retroviral origin. In exogenous retroviruses, the envelope glycoproteins coded by env genes allow fusion of the viral envelope with the host cell membrane and entry of the virus into a host cell. During mammalian evolution, the env genes have been repeatedly, and independently, captured by various mammalian species to facilitate the formation of the placenta. Such a shift in the function of a gene, or a trait, for a different purpose during evolution is called an exaptation (co-option). We discuss the structure and origin of the placenta, the fusogenic and non-fusogenic functions of syncytin, and the mechanism of cell fusion. We also comment on an alleged danger of the COVID-19 vaccine based on the presupposed similarity between syncytin and the SARS-CoV-2 spike protein.

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