Blow out. When an HIV protein is present, the nuclear membrane (green) may burst.
Researchers have discovered how HIV can penetrate the tight nucleus of an infected cell, a necessary step for the virus to replicate. Somehow, the virus sabotages the nuclear membrane with numerous punctures. The discovery could provide a new target for future drugs against AIDS.
The HIV (HIV) breeds entering the nucleus of a cell and supported. Once inside, copies of HIV DNA in its genome RNA, which slips into the cell's DNA. Then, when the cell prepares to divide, it copies inadvertently viral genome into RNA, the model for the manufacture of proteins. These proteins then assembled into new HIV particles which can infect other cells. To make more than one copy, the virus uses a protein called Vpr which stops the cell from normal cell division cycle. As a record skipping, the cell can not progress in the division, but the viral genome transcribed into RNA, again and again.
virologist Warner Greene and colleagues at the University of California, San Francisco, and Northwestern University Medical School, wanted to know how the virus stops the cell cycle. The team used video fluorescence microscopy to track the movement of proteins related to cell cycle-in and out of the cell nuclei, watch how traffic varies with the presence of Vpr. "I am astonished," said Greene. Vpr was present when the buttons appeared on the membrane surrounding the nucleus. Some curved until they burst, breaking the seal between the cytoplasm and the nucleus by an unknown mechanism. Reporting in the Nov. 2 issue of Science , the team suggests that these offenses can give HIV easy access to the nucleus. Normally, it is too large to pass through the membrane.
The conclusion only increases the respect of researchers for HIV. "It's blowing holes in the nuclear envelope, and it is just as radical as you can get," says cell biologist Katherine Wilson of the Johns Hopkins University School of Medicine. Wilson said the finding may encourage drug designers to consider Vpr as a potential antiviral target. "It is an important document," she said, "because it's making us look in a new direction."
Related Sites
Videos of Science article
Greene laboratory homepage
Wilson Homepage laboratory
0 Komentar