When retroviruses like HIV infect cells, they take over the cell's machinery to manufacture new copies of themselves. Research published this week in the top-tier open access journal, Journal of Biology, shows that to escape from cells, retroviruses may once again hijack cellular components, in this case molecules normally used to engulf material from the cell's surroundings in a pocket formed from cell membrane. The findings, offer new insights into how viruses propagate and cause disease, and how healthy cells work.
Retroviruses travel from cell to cell in 'spacecraft' surrounded by the membrane of host cells. These transporters protect the virus from attack by the immune system, as they disguise the virus as part of the body. The outer membrane of the virus particle also helps the virus to spread, as it can fuse with the membrane of other vulnerable cells.
During the construction of a virus particle, or virion, the cell membrane bulges outwards, engulfing viral components as it goes. One of the viral proteins, called Gag, is essential for this process.
Now, researchers from Columbia and Yale Universities, USA, Aijou University, South Korea and the Chinese Academy of Sciences has shown that some retroviral Gag proteins bind tightly to a host-cell protein called endophilin-2. Endophilin-2 is normally involved in the inward budding of the cell membrane, a process known as endocytosis.
Supporting the idea that this interaction is functionally relevant, the researchers found endophilin-2 inside viral particles that had budded from cells infected with Moloney-murine leukaemia virus. On further examination, they also found two other proteins involved in endocytosis, a-adaptin and clathrin, inside the virions. However, Dynamin-2, a protein that binds to endophilin-2, was not there. This suggests that the incorporation of selected proteins is unlikely to be accidental.
Endophilin-2's normal role is to increase the curvature of the Page: 1 2 Related biology news :1
Contact: Gemma Bradley
. Poetically Timed With Spring, Budding Yeast Yield Possible Insight Into Male Fertility--And Infertility2
. First glimpse of DNA binding to viral enzyme3
. X marks the spot: Vector insertion is viral specific4
. Retroviral gene therapy? ASLV, HIV, and MLV show distinct target site preferences5
. Researchers develop better understanding of immune response to viral infection6
. New papillomavirus target could lead to specific antiviral drugs for precancerous cervical lesions7
. Sick Kids researchers look at viral triggers for multiple sclerosis in children8
. The catch 22 of immune response to AIDs viral infection9
. A viral cure for type 1 diabetes10
. Purdue biologists expose the inner workings of viral machine11
. Retroviral protein triggers proliferation of immune cells