Membrane fusion, a fundamental process in cell biology, involves merging two phospholipid bilayers in an aqueous environment. Artificial bilayers fuse via hourglass-shaped intermediates, or fusion stalks, culminating in fusion pore opening. Biological membranes, however, need specialized fusion proteins, exemplified by viral proteins enabling viral-host cell merger during infection. These viral fusion proteins undergo spontaneous conformational shifts. The fusion proteins of HIV and influenza insert an amphiphilic fusion peptide into the target membrane, reorienting to force membrane merging and lipid mixing. Eukaryotic intracellular membrane fusion involves SNAREs, Rab proteins, and SM-proteins. SNAREs assemble into tightly packed helical bundles, pulling membranes together for fusion. SM-proteins bind SNAREs, preventing core complex formation, while Rab proteins, GTPases, connect fusing membranes initially, though not in the fusion reaction itself. Understanding membrane fusion mechanisms is vital for comprehending cellular processes and developing therapeutic interventions. From viral entry to intracellular trafficking, this research provides valuable insights into membrane fusion.
As a comprehensive review published in the Annual Review of Biochemistry, this article's broad scope and in-depth analysis are characteristic of the journal's aim to provide authoritative overviews of key biochemical topics. The article effectively summarizes the multifaceted processes of membrane fusion and exocytosis, making it a valuable resource for researchers in various fields.