Differential RNA Sequence Requirement for Dengue Virus Replication in Mosquito and Mammalian Cells

SERGIO VILLORDO; ANDREA GAMARNIK

JOURNAL OF VIROLOGY

AMER SOC MICROBIOLOGY

Lugar: Washington; Año: 2013 vol. 87 p. 9365 - 9372

0022-538X

Dengue virus cycles between mosquitoes and humans. Each host provides a different environment for viral replication, imposing different selective pressures. We identified a sequence in the dengue virus genome that is essential for viral replication in mosquito cells but not in mammalian cells. This sequence is located at the viral 3? untranslated region and folds into a small hairpin structure. A systematic mutational analysis using dengue virus infectious clones and reporter viruses allowed dissecting two putative functions in this cis-acting RNA motif, one linked to the structure and the other one linked to the nucleotide sequence. We found that single substitutions without altering the hairpin structure did not affect dengue virus replication in mammalian cells but abolished replication in mosquito cells. This is the first sequence identified in a flavivirus genome that is exclusively required for viral replication in insect cells.