| Structural highlights
Function
VTC1_YEAST Accessory subunit of the vacuolar transporter chaperone (VTC) complex. The VTC complex acts as a vacuolar polyphosphate polymerase that catalyzes the synthesis of inorganic polyphosphate (polyP) via transfer of phosphate from ATP to a growing polyP chain, releasing ADP. VTC exposes its catalytic domain VTC4 to the cytosol, where the growing polyP chain winds through a tunnel-shaped pocket, integrating cytoplasmic polymer synthesis with polyP membrane translocation (PubMed:19390046). The VTC complex carries 9 vacuolar transmembrane domains, which are likely to constitute the translocation channel into the organelle lumen (PubMed:19390046, PubMed:25315834). PolyP synthesis is tightly coupled to its transport into the vacuole lumen, in order to avoid otherwise toxic intermediates in the cytosol, and it depends on the proton gradient across the membrane, formed by V-ATPase (PubMed:25315834). VTC1 contributes only 3 transmembrane domains to the complex (Probable). The VTC complex also plays a role in vacuolar membrane fusion (PubMed:10480897, PubMed:11102525, PubMed:11823419, PubMed:12584253). Required for SEC18/NSF activity in SNARE priming, membrane binding of LMA1 and V(0) trans-complex formation (PubMed:11823419).[1] [2] [3] [4] [5] [6] [7]
References
- ↑ Cohen A, Perzov N, Nelson H, Nelson N. A novel family of yeast chaperons involved in the distribution of V-ATPase and other membrane proteins. J Biol Chem. 1999 Sep 17;274(38):26885-93. PMID:10480897 doi:10.1074/jbc.274.38.26885
- ↑ Ogawa N, DeRisi J, Brown PO. New components of a system for phosphate accumulation and polyphosphate metabolism in Saccharomyces cerevisiae revealed by genomic expression analysis. Mol Biol Cell. 2000 Dec;11(12):4309-21. PMID:11102525
- ↑ Muller O, Bayer MJ, Peters C, Andersen JS, Mann M, Mayer A. The Vtc proteins in vacuole fusion: coupling NSF activity to V(0) trans-complex formation. EMBO J. 2002 Feb 1;21(3):259-69. PMID:11823419 doi:https://dx.doi.org/10.1093/emboj/21.3.259
- ↑ Muller O, Neumann H, Bayer MJ, Mayer A. Role of the Vtc proteins in V-ATPase stability and membrane trafficking. J Cell Sci. 2003 Mar 15;116(Pt 6):1107-15. PMID:12584253
- ↑ Hothorn M, Neumann H, Lenherr ED, Wehner M, Rybin V, Hassa PO, Uttenweiler A, Reinhardt M, Schmidt A, Seiler J, Ladurner AG, Herrmann C, Scheffzek K, Mayer A. Catalytic core of a membrane-associated eukaryotic polyphosphate polymerase. Science. 2009 Apr 24;324(5926):513-6. PMID:19390046 doi:324/5926/513
- ↑ Gerasimaitė R, Sharma S, Desfougères Y, Schmidt A, Mayer A. Coupled synthesis and translocation restrains polyphosphate to acidocalcisome-like vacuoles and prevents its toxicity. J Cell Sci. 2014 Dec 1;127(Pt 23):5093-104. PMID:25315834 doi:10.1242/jcs.159772
- ↑ Hothorn M, Neumann H, Lenherr ED, Wehner M, Rybin V, Hassa PO, Uttenweiler A, Reinhardt M, Schmidt A, Seiler J, Ladurner AG, Herrmann C, Scheffzek K, Mayer A. Catalytic core of a membrane-associated eukaryotic polyphosphate polymerase. Science. 2009 Apr 24;324(5926):513-6. PMID:19390046 doi:324/5926/513
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