The SNARE complex formed by RIC-4/SEC-22/SYX-2 promotes C. elegans epidermal wound healing.

Area of Science:

• Cell Biology
• Molecular Biology
• Membrane Biology

Background:

• Cellular viability depends on plasma membrane integrity, necessitating efficient repair mechanisms.
• Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE)-mediated membrane fusion is a key process in membrane repair.
• Syntaxin-2 (SYX-2) is known to be involved in large membrane wound repair in C. elegans epidermal cells, but the molecular details are unclear.

Purpose of the Study:

• To elucidate the molecular mechanism underlying SYX-2 recruitment and SNARE complex formation in C. elegans membrane repair.
• To identify the specific protein partners and regulatory factors involved in repairing large plasma membrane wounds.

Main Methods:

• Investigated the roles of RIC-4 (SNAP-25) and SEC-22 (synaptobrevin) in SYX-2 recruitment using C. elegans models.
• Utilized in vivo and in vitro assays to assess SNARE complex formation and membrane fusion.
• Examined the intracellular localization of SEC-22 and the impact of RAB-5 inhibition on its localization and interactions.

Main Results:

• RIC-4 and SEC-22 are essential for recruiting SYX-2 to sites of membrane damage.
• RIC-4 and SEC-22 form a SNARE complex that promotes both in vivo membrane repair and in vitro membrane fusion.
• SEC-22 localizes to endosomes and the trans-Golgi network and is recruited to wound sites.
• RAB-5 is crucial for proper SEC-22 localization and its interaction with SYX-2.

Conclusions:

• RAB-5 plays a critical role in facilitating the assembly of the RIC-4/SEC-22/SYX-2 SNARE complex.
• This study provides significant insights into the molecular machinery governing the repair of large membrane wounds.
• The findings highlight a novel mechanism involving SNARE complex formation and RAB-5 regulation in cellular membrane repair.