Fusion-associated small transmembrane protein (FAST protein)

Fusion-associated small transmembrane proteins (FAST proteins) are a unique family of nonstructural viral proteins encoded by fusogenic reoviruses (non-enveloped viruses) that mediate cell–cell membrane fusion, leading to the formation of multinucleated syncytia[6][7][2][3]. Unlike typical viral fusion proteins that enable virus entry into host cells, FAST proteins specifically evolved to mediate direct cytoplasmic continuity between host cells, thereby facilitating virus dissemination without the need for viral envelope fusion[6][7]. They are the smallest known viral membrane fusion proteins, possessing a simple modular structure with a central transmembrane domain, short extracellular and cytosolic regions, and specific fusogenic motifs[2][3][4]. FAST proteins do not function as receptors, enzymes, transporters, or host-derived drug targets—they are specialized viral proteins and thus are not conventionally considered therapeutic targets[6][7]. Summary of correctness and target status: There is something incorrect or misleading about the target as stated in your prompt: "Cell membrane lipid bilayer fusion via Fusion Associated Small Transmembrane protein-mediated direct cytoplasmic entry" is more a biological process mediated by FAST proteins rather than a discrete target molecule or receptor that would be conventionally druggable[6][7]. The correct entry should focus on the viral protein FAST, not the process. FAST proteins are not standard targets in drug discovery, and no drugs act directly on them; thus "is_target" should be false and "is_incorrect" true. If further structured data are needed, the entry should focus on "Fusion-associated small transmembrane protein (FAST protein)" as the canonical target name, with the above information populated.

Other names

fusion-associated small transmembrane proteinFAST proteinFAST family proteinviral fusogen