Kuan-Teh Jeang, M.D., Ph.D., of NIAID led the research team reporting their discovery in the Oct. 29 issue of Cell.
"This finding provides new insights into a crucial step in HIV replication," says Anthony S. Fauci, M.D., director of NIAID. "The discovery also provides an attractive target for drug development which, if successful, might in time give us a completely new type of HIV drug that circumvents the problem of drug resistance."
Dr. Jeang's team found evidence that the virus co-opts an enzyme produced by human cells to transport HIV's genetic material out of the cell nucleus. Once out of the nucleus, these messenger RNAs begin directing the cell to create and assemble new virus particles.
The process of how HIV genetic material--a long unedited strand of RNA--exits the cell nucleus has long puzzled scientists. Human cells cut, edit and splice RNA before it can leave the nucleus, but somehow HIV subverts that process and exports from the nucleus the long version of RNA that encodes instructions for making new viral particles.
Scientists knew that HIV makes a protein called Rev to help skirt the prohibition on transporting the lengthy, unedited version of RNA from the nucleus. They also knew that HIV commandeers a human protein known as CRM1 to aid in this process. Rev and CRM1 together, however, are insufficient to explain how HIV flouts the molecular machinery that cuts and splices RNA before it leaves the nucleus.
"Unspliced RNA is like an unwieldy ball of yar
Contact: Linda Joy
NIH/National Institute of Allergy and Infectious Diseases