Fusogene

Fusogene is a term used in genetics and synthetic biology to denote a gene or engineered protein that promotes fusion between cell membranes. It encompasses natural fusogenic proteins derived from viruses or cellular systems, as well as synthetic or de novo designed constructs intended to trigger membrane merger between adjacent cells. In practice, fusogenes are used to create multinucleated cells or to mix cytoplasmic contents for experimental purposes, and the term is applied variably across disciplines.

Mechanism and applications: Fusogenes typically function by promoting close contact of lipid bilayers and triggering the merger of the outer membrane leaflets, followed by pore formation that yields cytoplasmic continuity. Activation depends on factors such as proteolytic processing, receptor engagement, pH, or co-factors, and the cellular context influences efficiency and specificity. In research, fusogenes enable the creation of heterokaryons for functional analyses, lineage tracing, or complementation studies; in tissue engineering they may be explored to unite different cell types or deliver cytoplasmic components, with speculative therapeutic uses in targeted gene delivery.

Safety, governance, and terminology: The potential for off-target fusion, genomic instability, and tumorigenicity raises biosafety concerns, prompting strict containment and risk assessment. Regulatory frameworks across jurisdictions address ethical considerations, data reporting, and long-term monitoring. The term fusogene is not standardized; it is used to describe any gene or construct with fusogenic activity, leading to variation in how it is defined in literature. See also: fusogen, cell fusion, SNARE proteins, membrane fusion, synthetic biology.