Enhanced Fusion Pore Expansion Mediated by the Trans-Acting Endodomain of the Reovirus FAST Proteins

• DOI: 10.1371/journal.ppat.1000331
• Publication Date: 2009-03-06T02:02:59Z
• Authors: Deniz Top; Chris Barry; Trina Racine; Chelsey Louise Ellis; Roy Duncan
• Keywords: Cell fusion

The reovirus fusion-associated small transmembrane (FAST) proteins are virus-encoded membrane fusion that function as dedicated cell–cell fusogens. topology of these small, single-pass orients the majority protein on distal side (i.e., inside cell). We now show ectopic expression endodomains p10, p14, and p15 FAST enhances syncytiogenesis induced by full-length proteins, both homotypically heterotypically. Results further indicate 68-residue cytoplasmic endodomain p14 (1) is endogenously generated from expressed in virus-infected or transfected cells; (2) subsequent to stable pore formation; (3) increases syncytiogenic activity heterologous including differentiation-dependent murine myoblasts; (4) exerts its enhancing cytosol, independent direct interactions with either fusogen membranes being fused; (5) contains several regions protein–protein interaction motifs influence activity. propose unique evolution cellular fusogens has allowed them generate a trans-acting, soluble peptide harness pathway process involved poorly understood facilitates transition microfusion pores macrofusion syncytiogenesis.