HIV-Tat protein forms phosphoinositide-dependent membrane pores implicated in unconventional protein secretion

Abstract

Background: Unconventional secretion of both HIV-Tat and FGF2 depends on the phosphoinositide PI(4,5)P2. Results: HIV-Tat forms membrane-inserted oligomers concomitant with PI(4,5)P2-dependent membrane pore formation. Conclusion: HIV-Tat and FGF2 show similar properties with a tight correlation between membrane pore formation and unconventional secretion from cells. Significance: Evidence is provided that suggests a common mechanism of unconventional secretion with potential relevance for a broad range of cargoes.