Transport of sequence-specific RNA interference information between cells.
When eukaryotic cells encounter double-stranded RNA, genes of matching sequence are silenced through RNA interference. Surprisingly, in some animals and plants, the same gene is specifically silenced even in cells that did not encounter the double-stranded RNA, due to the transport of a gene-specific silencing signal between cells. This silencing signal likely has an RNA component that gives it sequence-specificity, however its precise identity remains unknown. Studies in the worm Caenorhabditis elegans and in plants have revealed parts of a complex protein machinery that transports this silencing signal. Some of these proteins are conserved in vertebrates, including mammals, raising the possibility that higher animals can communicate gene-specific silencing information between cells. Such communication provides antiviral immunity in plants and perhaps in C. elegans. Identifying the transported silencing signal and deciphering the evolutionarily selected role of the transport machinery are some of the key challenges for the future.
Jose
Antony M
AM
Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA. amjose@mcb.harvard.edu
Hunter
Craig P
CP
D000818:Animals; D001692:Biological Transport; D017173:Caenorhabditis elegans / Q000235:genetics; D020868:Gene Silencing; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics
D034741:RNA, Small Interfering