biostudies-literatureWu SNIH Biology and Biotechnology of Cell and Gene Therapy Training ProgramHoward Hughes Medical InstituteMedical Research CouncilAligning Science Across Parkinson'sNIGMS NIH HHSNIH HHSParkinson's UKe85837https://www.ebi.ac.uk/biostudies/studies/S-EPMC9876576biostudies-literatureUnknown12Alpha-synuclein (α-syn), a major component of Lewy bodies found in Parkinson's disease (PD) patients, has been found exported outside of cells and may mediate its toxicity via cell-to-cell transmission. Here, we reconstituted soluble, monomeric α-syn secretion by the expression of DnaJ homolog subfamily C member 5 (DNAJC5) in HEK293T cells. DNAJC5 undergoes palmitoylation and anchors on the membrane. Palmitoylation is essential for DNAJC5-induced α-syn secretion, and the secretion is not limited by substrate size or unfolding. Cytosolic α-syn is actively translocated and sequestered in an endosomal membrane compartment in a DNAJC5-dependent manner. Reduction of α-syn secretion caused by a palmitoylation-deficient mutation in DNAJC5 can be reversed by a membrane-targeting peptide fusion-indeLifeUnconventional secretion of α-synuclein mediated by palmitoylated DNAJC5 oligomers.PMC9876576MR/M024962/1H-1301K-1003H-1102MC_EX_MR/N50192X/1MR/P007058/1MR/N029453/1NIH training program T32GM139780G-1003T32 GM139780MR/L023784/2G-0801J-0901ASAP-020370J-1403Wade-Martins RSchekman RWu SHernandez Villegas NCThomas-Wright ISirkis DWfalseUnconventional secretion of α-synuclein mediated by palmitoylated DNAJC5 oligomers.Alpha-synuclein (α-syn), a major component of Lewy bodies found in Parkinson's disease (PD) patients, has been found exported outside of cells and may mediate its toxicity via cell-to-cell transmission. Here, we reconstituted soluble, monomeric α-syn secretion by the expression of DnaJ homolog subfamily C member 5 (DNAJC5) in HEK293T cells. DNAJC5 undergoes palmitoylation and anchors on the membrane. Palmitoylation is essential for DNAJC5-induced α-syn secretion, and the secretion is not limited by substrate size or unfolding. Cytosolic α-syn is actively translocated and sequestered in an endosomal membrane compartment in a DNAJC5-dependent manner. Reduction of α-syn secretion caused by a palmitoylation-deficient mutation in DNAJC5 can be reversed by a membrane-targeting peptide fusion-ind2023-01-01T00:00:00Z2023 Jan2026-05-29T05:31:45.355Z2025-02-18T23:45:10.471ZS-EPMC98765763662630710.7554/eLife.85837