Three V-SNAREs and Two T-SNAREs, Present in a Pentameric Cis-SNARE Complex on Isolated Vacuoles, Are Essential for Homotypic Fusion
Overview
Affiliations
Vacuole SNAREs, including the t-SNAREs Vam3p and Vam7p and the v-SNARE Nyv1p, are found in a multisubunit "cis" complex on isolated organelles. We now identify the v-SNAREs Vti1p and Ykt6p by mass spectrometry as additional components of the immunoisolated vacuolar SNARE complex. Immunodepletion of detergent extracts with anti-Vti1p removes all the Ykt6p that is in a complex with Vam3p, immunodepletion with anti-Ykt6p removes all the Vti1p that is complexed with Vam3p, and immunodepletion with anti-Nyv1p removes all the Ykt6p in complex with other SNAREs, demonstrating that they are all together in the same cis multi-SNARE complex. After priming, which disassembles the cis-SNARE complex, antibodies to any of the five SNARE proteins still inhibit the fusion assay until the docking stage is completed, suggesting that each SNARE plays a role in docking. Furthermore, vti1 temperature-sensitive alleles cause a synthetic fusion-defective phenotype in our reaction. Our data show that vacuole-vacuole fusion requires a cis-SNARE complex of five SNAREs, the t-SNAREs Vam3p and Vam7p and the v-SNAREs Nyv1p, Vti1p, and Ykt6p.
ULK1-mediated phosphorylation regulates the conserved role of YKT6 in autophagy.
Sanchez-Martin P, Kriegenburg F, Alves L, Adam J, Elsaesser J, Babic R J Cell Sci. 2023; 136(3).
PMID: 36644903 PMC: 10022743. DOI: 10.1242/jcs.260546.
Dynamin controls neuropeptide secretion by organizing dense-core vesicle fusion sites.
Moro A, van Nifterick A, Toonen R, Verhage M Sci Adv. 2021; 7(21).
PMID: 34020952 PMC: 8139595. DOI: 10.1126/sciadv.abf0659.
Atg1 kinase regulates autophagosome-vacuole fusion by controlling SNARE bundling.
Barz S, Kriegenburg F, Henning A, Bhattacharya A, Mancilla H, Sanchez-Martin P EMBO Rep. 2020; 21(12):e51869.
PMID: 33274589 PMC: 7726815. DOI: 10.15252/embr.202051869.
Phosphorylation of Ykt6 SNARE Domain Regulates Its Membrane Recruitment and Activity.
Karuna M P, Witte L, Linnemannstoens K, Choezom D, Danieli-Mackay A, Honemann-Capito M Biomolecules. 2020; 10(11).
PMID: 33207719 PMC: 7696345. DOI: 10.3390/biom10111560.
Function of the SNARE Ykt6 on autophagosomes requires the Dsl1 complex and the Atg1 kinase complex.
Gao J, Kurre R, Rose J, Walter S, Frohlich F, Piehler J EMBO Rep. 2020; 21(12):e50733.
PMID: 33025734 PMC: 7726795. DOI: 10.15252/embr.202050733.