Actin Polymerization and ESCRT Trigger Recruitment of the Fusogens Syntaxin-2 and EFF-1 to Promote Membrane Repair in C. elegans

Abstract

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.

Keywords: EFF-1; ESCRT; SYX-2; actin polymerization; fusogen; membrane fusion; plasma membrane repair; t-SNARE; wound healing.