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Karuna M P, Witte L, Linnemannstoens K, Choezom D, Danieli-Mackay A, Honemann-Capito M, Gross JC. Phosphorylation of Ykt6 SNARE Domain Regulates Its Membrane Recruitment and Activity. Biomolecules 2020; 10:biom10111560. [PMID: 33207719 PMCID: PMC7696345 DOI: 10.3390/biom10111560] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/10/2020] [Accepted: 11/11/2020] [Indexed: 12/17/2022] Open
Abstract
Sensitive factor attachment protein receptors (SNARE) proteins are important mediators of protein trafficking that regulate the membrane fusion of specific vesicle populations and their target organelles. The SNARE protein Ykt6 lacks a transmembrane domain and attaches to different organelle membranes. Mechanistically, Ykt6 activity is thought to be regulated by a conformational change from a closed cytosolic form to an open membrane-bound form, yet the mechanism that regulates this transition is unknown. We identified phosphorylation sites in the SNARE domain of Ykt6 that mediate Ykt6 membrane recruitment and are essential for cellular growth. Using proximity-dependent labeling and membrane fractionation, we found that phosphorylation regulates Ykt6 conversion from a closed to an open conformation. This conformational switch recruits Ykt6 to several organelle membranes, where it functionally regulates the trafficking of Wnt proteins and extracellular vesicle secretion in a concentration-dependent manner. We propose that phosphorylation of its SNARE domain leads to a conformational switch from a cytosolic, auto-inhibited Ykt6 to an active SNARE at different membranes.
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Affiliation(s)
- Pradhipa Karuna M
- Hematology and Oncology, University Medical Center Goettingen, 37077 Goettingen, Germany; (P.K.M.); (L.W.); (K.L.); (D.C.); (A.D.-M.); (M.H.-C.)
- Developmental Biochemistry, University Medical Center Goettingen, 37077 Goettingen, Germany
| | - Leonie Witte
- Hematology and Oncology, University Medical Center Goettingen, 37077 Goettingen, Germany; (P.K.M.); (L.W.); (K.L.); (D.C.); (A.D.-M.); (M.H.-C.)
- Developmental Biochemistry, University Medical Center Goettingen, 37077 Goettingen, Germany
| | - Karen Linnemannstoens
- Hematology and Oncology, University Medical Center Goettingen, 37077 Goettingen, Germany; (P.K.M.); (L.W.); (K.L.); (D.C.); (A.D.-M.); (M.H.-C.)
- Developmental Biochemistry, University Medical Center Goettingen, 37077 Goettingen, Germany
| | - Dolma Choezom
- Hematology and Oncology, University Medical Center Goettingen, 37077 Goettingen, Germany; (P.K.M.); (L.W.); (K.L.); (D.C.); (A.D.-M.); (M.H.-C.)
- Developmental Biochemistry, University Medical Center Goettingen, 37077 Goettingen, Germany
| | - Adi Danieli-Mackay
- Hematology and Oncology, University Medical Center Goettingen, 37077 Goettingen, Germany; (P.K.M.); (L.W.); (K.L.); (D.C.); (A.D.-M.); (M.H.-C.)
- Developmental Biochemistry, University Medical Center Goettingen, 37077 Goettingen, Germany
| | - Mona Honemann-Capito
- Hematology and Oncology, University Medical Center Goettingen, 37077 Goettingen, Germany; (P.K.M.); (L.W.); (K.L.); (D.C.); (A.D.-M.); (M.H.-C.)
- Developmental Biochemistry, University Medical Center Goettingen, 37077 Goettingen, Germany
| | - Julia Christina Gross
- Hematology and Oncology, University Medical Center Goettingen, 37077 Goettingen, Germany; (P.K.M.); (L.W.); (K.L.); (D.C.); (A.D.-M.); (M.H.-C.)
- Developmental Biochemistry, University Medical Center Goettingen, 37077 Goettingen, Germany
- HMU Health and Medical University Potsdam, 14471 Potsdam, Germany
- Correspondence:
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