Palmitoyl-protein thioesterase 1 (PPT1) is a lysosomal depalmitoylation enzyme that mediates protein posttranslational modifications. Loss-of-function mutation of PPT1 causes a failure of the lysosomal degradation of palmitoylated proteins and results in a congenital disease characterized by progressive neuronal degeneration referred to as infantile neuronal ceroid lipofuscinosis (INCL). A mouse knock-in model of PPT1 (PPT1-KI) was established by introducing the R151X mutation into exon 5 of the PPT1 gene, which exhibited INCL-like pathological lesions.
View Article and Find Full Text PDFVesicle fusion is executed via formation of an Ω-shaped structure (Ω-profile), followed by closure (kiss-and-run) or merging of the Ω-profile into the plasma membrane (full fusion). Although Ω-profile closure limits release but recycles vesicles economically, Ω-profile merging facilitates release but couples to classical endocytosis for recycling. Despite its crucial role in determining exocytosis/endocytosis modes, how Ω-profile merging is mediated is poorly understood in endocrine cells and neurons containing small ∼30-300 nm vesicles.
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