Abstract
Eukaryotic cell homeostasis requires transfer of cellular components among organelles and relies on membrane fusion catalyzed by SNARE proteins. Inactive SNARE bundles are reactivated by hexameric N-ethylmaleimide-sensitive factor, vesicle-fusing ATPase (Sec18/NSF)-driven disassembly that enables a new round of membrane fusion. We previously found that phosphatidic acid (PA) binds Sec18 and thereby sequesters it from SNAREs and that PA dephosphorylation dissociates Sec18 from the membrane, allowing it to engage SNARE complexes. We now report that PA also induces conformational changes in Sec18 protomers and that hexameric Sec18 cannot bind PA membranes. Molecular dynamics (MD) analyses revealed that the D1 and D2 domains of Sec18 contain PA-binding sites and that the residues needed for PA binding are masked in hexameric Sec18. Importantly, these simulations also disclosed that a major conformational change occurs in the linker region between the D1 and D2 domains, which is distinct from the conformational changes that occur in hexameric Sec18 during SNARE priming. Together, these findings indicate that PA regulates Sec18 function by altering its architecture and stabilizing membrane-bound Sec18 protomers.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 3100-3116 |
| Number of pages | 17 |
| Journal | Journal of Biological Chemistry |
| Volume | 294 |
| Issue number | 9 |
| DOIs | |
| State | Published - Jan 1 2019 |
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ASJC Scopus subject areas
- Biochemistry
- Molecular Biology
- Cell Biology
Cite this
Phosphatidic acid induces conformational changes in Sec18 protomers that prevent SNARE priming. / Starr, Matthew L.; Sparks, Robert P.; Arango, Andres S.; Hurst, Logan R.; Zhao, Zhiyu; Lihan, Muyun; Jenkins, Jermaine L.; Tajkhorshid, Emad; Fratti, Rutilio A.
In: Journal of Biological Chemistry, Vol. 294, No. 9, 01.01.2019, p. 3100-3116.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Phosphatidic acid induces conformational changes in Sec18 protomers that prevent SNARE priming
AU - Starr, Matthew L.
AU - Sparks, Robert P.
AU - Arango, Andres S.
AU - Hurst, Logan R.
AU - Zhao, Zhiyu
AU - Lihan, Muyun
AU - Jenkins, Jermaine L.
AU - Tajkhorshid, Emad
AU - Fratti, Rutilio A.
PY - 2019/1/1
Y1 - 2019/1/1
N2 - Eukaryotic cell homeostasis requires transfer of cellular components among organelles and relies on membrane fusion catalyzed by SNARE proteins. Inactive SNARE bundles are reactivated by hexameric N-ethylmaleimide-sensitive factor, vesicle-fusing ATPase (Sec18/NSF)-driven disassembly that enables a new round of membrane fusion. We previously found that phosphatidic acid (PA) binds Sec18 and thereby sequesters it from SNAREs and that PA dephosphorylation dissociates Sec18 from the membrane, allowing it to engage SNARE complexes. We now report that PA also induces conformational changes in Sec18 protomers and that hexameric Sec18 cannot bind PA membranes. Molecular dynamics (MD) analyses revealed that the D1 and D2 domains of Sec18 contain PA-binding sites and that the residues needed for PA binding are masked in hexameric Sec18. Importantly, these simulations also disclosed that a major conformational change occurs in the linker region between the D1 and D2 domains, which is distinct from the conformational changes that occur in hexameric Sec18 during SNARE priming. Together, these findings indicate that PA regulates Sec18 function by altering its architecture and stabilizing membrane-bound Sec18 protomers.
AB - Eukaryotic cell homeostasis requires transfer of cellular components among organelles and relies on membrane fusion catalyzed by SNARE proteins. Inactive SNARE bundles are reactivated by hexameric N-ethylmaleimide-sensitive factor, vesicle-fusing ATPase (Sec18/NSF)-driven disassembly that enables a new round of membrane fusion. We previously found that phosphatidic acid (PA) binds Sec18 and thereby sequesters it from SNAREs and that PA dephosphorylation dissociates Sec18 from the membrane, allowing it to engage SNARE complexes. We now report that PA also induces conformational changes in Sec18 protomers and that hexameric Sec18 cannot bind PA membranes. Molecular dynamics (MD) analyses revealed that the D1 and D2 domains of Sec18 contain PA-binding sites and that the residues needed for PA binding are masked in hexameric Sec18. Importantly, these simulations also disclosed that a major conformational change occurs in the linker region between the D1 and D2 domains, which is distinct from the conformational changes that occur in hexameric Sec18 during SNARE priming. Together, these findings indicate that PA regulates Sec18 function by altering its architecture and stabilizing membrane-bound Sec18 protomers.
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UR - http://www.scopus.com/inward/citedby.url?scp=85063468706&partnerID=8YFLogxK
U2 - 10.1074/jbc.RA118.006552
DO - 10.1074/jbc.RA118.006552
M3 - Article
C2 - 30617180
AN - SCOPUS:85063468706
VL - 294
SP - 3100
EP - 3116
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 9
ER -