Immunoelectron Microscopic Evidence for Tetherin/BST2 as the Physical Bridge between HIV-1 Virions and the Plasma Membrane

• DOI: 10.1371/journal.ppat.1000749
• Publication Date: 2010-02-04T22:45:48Z
• Authors: Jason Hammonds; Jaang-Jiun Wang; Hong Yi; Paul Spearman
• Keywords: Tetherin; Immunoelectron microscopy; Cell membrane

Tetherin/BST2 was identified in 2008 as the cellular factor responsible for restricting HIV-1 replication at a very late stage lifecycle. Tetherin acts to retain virion particles on plasma membrane after budding has been completed. Infected cells that express large amounts of tetherin display strings HIV virions remain attached membrane. Vpu is an accessory protein specifically counteracts restriction virus release contributed by tetherin. unusual Type II transmembrane contains GPI anchor its C-terminus and found lipid rafts. The leading model mechanism action it functions direct physical tether bridging However, evidence thus far indirect. Here we demonstrate biochemical immunoelectron microscopic methods endogenous present viral particle forms bridge between Endogenous were released partial proteolytic digestion. Immunoelectron microscopy performed HIV-infected T demonstrated apparent link connects patches Linear filamentous strands highly enriched bridged space some virions. We conclude linking presence filaments with which multiple molecules interact connecting strongly suggested morphologic evidence.