Viral hijack of receptors
Article Abstract:
A biochemical signal that causes some type of response by a cell can be transmitted from the outside of the cell to the inside by the binding of molecules outside the cell to receptors on the cell that are attached to proteins, known as G proteins, which in turn generate intracellular signals. When signalling systems that are mediated by G proteins are disrupted, whole cellular networks can be disrupted in turn. Toxins produced by bacteria, such as those that cause cholera and whooping cough, can block G proteins or cause overproduction of the intracellular signal. Insect toxins can also cause cell activation. Some of the oncogenes, genes that are involved in cancer, code for defective G proteins or receptors that bind to G proteins. The human cytomegalovirus (CMV), a member of the herpesvirus family, can cause widespread infection, which is often sexually transmitted. CMV has been shown to contain three genes which are predicted to code for three G-protein-coupled receptors. It is thought that the CMV acquires the genes for the G protein-coupled receptors from the host cells, similar to the way in which tumor viruses pick up oncogenes. How the CMV-encoded receptors function in the life cycle of the virus is not known, but possibilities include: altering the host-cell metabolism; affecting the replication of the virus; suppressing the anti-viral activity of the host; and determining what cells or tissues are susceptible to viral infection. Understanding the biology of these receptors and the molecules they bind may provide a new way to introduce drugs into the virus to prevent infection by CMV. (Consumer Summary produced by Reliance Medical Information, Inc.)
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1990
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The ribosome talks back
Article Abstract:
The synthesis of mammalian membrane and secretory proteins involves the GTPase cycles of the signal-recognition particle (SRP) and the SRP receptor. The 54K subunit of the SRP identifies the ribosomes that produce nascent chains containing the ER-directed signal sequences. The GTPase cycle collects the cytosolic-bound components and the receptors recruit membrane-bound components. This activity catalyzes the formation of the ribosome-membrane junction. A model helps in explaining the requirement for two GTPase switches despite some of its drawbacks.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 1996
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angiotensin-converting enzyme 2 is a functional receptor for the SARS coronavirus
Article Abstract:
Research demonstrates efficien binding of the severe acute respiratory syndrome (SARS)-CoV S protein by the angiotensin-converting enzyme 2 (ACE2) from SARS coronavirus-permissive Vero E6 cells, suggesting that ACE2 is a functional receptor for SARS-CoV.
Publication Name: Nature
Subject: Zoology and wildlife conservation
ISSN: 0028-0836
Year: 2003
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