A dynamin homolog promotes the transition from hemifusion to content mixing in intracellular membrane fusion.
The convergence of the antagonistic reactions of membrane fusion and fission at the hemifusion/hemifission intermediate has generated a captivating enigma of whether Soluble N-ethylmaleimide sensitive factor Attachment Protein Receptor (SNAREs) and dynamin have unusual counter-functions in fission and fusion, respectively. SNARE-mediated fusion and dynamin-driven fission are fundamental membrane flux reactions known to occur during ubiquitous cellular communication events such as exocytosis, endocytosis and vesicle transport. Here we demonstrate the influence of the dynamin homolog Vps1 (Vacuolar protein sorting 1) on lipid mixing and content mixing properties of yeast vacuoles, and on the incorporation of SNAREs into fusogenic complexes. We propose a novel concept that Vps1, through its oligomerization and SNARE domain binding, promotes the hemifusion-content mixing transition in yeast vacuole fusion by increasing the number of trans-SNAREs.
Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
Aditya
A
Kulkarni
Kannan
K
Alpadi
Tirupataiah
T
Sirupangi
Christopher
C
Peters
D034281:Dynamins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism* / Q000502:physiology*; D008051:Lipid Bilayers / Q000378:metabolism; D008561:Membrane Fusion / Q000502:physiology*; D021381:Protein Transport / Q000502:physiology; D050600:SNARE Proteins / Q000378:metabolism; D014617:Vacuoles / Q000378:metabolism / Q000502:physiology; D015003:Yeasts / Q000378:metabolism / Q000502:physiology
D005656:Fungal Proteins; D008051:Lipid Bilayers; D050600:SNARE Proteins; D034281:Dynamins
SNAREs; Syntaxin; Vam3; Vps1; dynamin superfamily; endocytosis; exocytosis; hemifusion; membrane fusion; neurotransmitter release