Maintaining cellular viability relies on the integrity of the plasma membrane, which must be repaired upon damage. Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-mediated membrane fusion is a crucial mechanism involved in membrane repair. In C. elegans epidermal cell hyp 7, syntaxin-2 (SYX-2) facilitates large membrane wound repair; however, the underlying molecular mechanism remains unclear. Here, we found that SNAP-25 protein RIC-4 and synaptobrevin protein SEC-22 are required for SYX-2 recruitment at the wound site. They interact to form a SNARE complex to promote membrane repair in vivo and fusion in vitro. Moreover, we found that SEC-22 localized in multiple intracellular compartments, including endosomes and the trans-Golgi network, which recruited to the wounds. Furthermore, inhibition of RAB-5 disrupted SEC-22 localization and prevented its interaction with SYX-2. Our findings suggest that RAB-5 facilitates the formation of the RIC-4/SEC-22/SYX-2 SNARE complex and provides valuable insights into the molecular mechanism of how cells repair large membrane wounds.

Membrane repair is essential for cell and organism survival. Exocytosis and endocytosis facilitate membrane repair in small wounds within a single cell; however, it remains unclear how large wounds in the plasma membrane are repaired in metazoans. Here, we show that wounding triggers rapid transcriptional upregulation and dynamic recruitment of the fusogen EFF-1 to the wound site in C. elegans epidermal cells. EFF-1 recruitment at the wounded membrane depends on the actin cytoskeleton and is important for membrane repair. We identified syntaxin-2 (SYX-2) as an essential regulator of EFF-1 recruitment. SYX-2 interacts with the C terminus of EFF-1 to promote its recruitment, facilitating both endoplasmic and exoplasmic membrane repair. Furthermore, we show that SYX-2-EFF-1 repair machinery acts downstream of the ESCRT III signal. Together, our findings identify a key pathway underlying membrane repair and provide insights into tissue repair and regenerative medicine after injury.