Structural highlights
Function
[VATG_YEAST] Catalytic subunit of the peripheral V1 complex of vacuolar ATPase (V-ATPase). V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. [VATL1_YEAST] Proton-conducting pore forming subunit of the membrane integral V0 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. It is an electrogenic proton pump that generates a proton motive force of 180 mv, inside positive and acidic, in the vacuolar membrane vesicles. [VATA_YEAST] Catalytic subunit of the peripheral V1 complex of vacuolar ATPase. V-ATPase (vacuolar ATPase) is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. It is an electrogenic proton pump that generates a proton motive force of 180 mV, inside positive and acidic, in the vacuolar membrane vesicles. It may participate in maintenance of cytoplasmic Ca(2+) homeostasis. This is a catalytic subunit.[1] PI-SceI is an endonuclease that can cleave at a site present in a VMA1 allele that lacks the derived endonuclease segment of the open reading frame; cleavage at this site only occurs during meiosis and initiates "homing", a genetic event that converts a VMA1 allele lacking VDE into one that contains it.[2] [VATE_YEAST] Subunit of the peripheral V1 complex of vacuolar ATPase essential for assembly or catalytic function. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. [VPH1_YEAST] Subunit of the integral membrane V0 complex of vacuolar ATPase essential for assembly and catalytic activity. Is present only in vacuolar V-ATPase complexes. Enzymes containing this subunit have a 4-fold higher ratio of proton transport to ATP hydrolysis than complexes containing the Golgi/endosomal isoform and undergo reversible dissociation of V1 and V0 in response to glucose depletion. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells.[3] [4] [5] [VATF_YEAST] Subunit of the peripheral V1 complex of vacuolar ATPase essential for assembly or catalytic function. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. [VATH_YEAST] Vacuolar ATPases regulate the organelle acidity. This subunit is essential for activity, but not assembly, of the enzyme complex. [VATD_YEAST] Subunit of the peripheral V1 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells, thus providing most of the energy required for transport processes in the vacuolar system. [VATB_YEAST] Non-catalytic subunit of the peripheral V1 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. It is an electrogenic proton pump that generates a proton motive force of 180 mv, inside positive and acidic, in the vacuolar membrane vesicles.[6] [VATC_YEAST] Subunit of the peripheral V1 complex of vacuolar ATPase. Subunit C acts as a flexible stator that holds together the catalytic and the membrane sectors of the enzyme. Reversibly leaves the enzyme after glucose depletion, causing the catalytic subcomplex V1 to detach from the V0 section. Binds ATP and is likely to have a specific function in the catalytic activity of the catalytic sector. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells.[7] [VA0D_YEAST] Vacuolar ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. The active enzyme consists of a catalytic V1 domain attached to an integral membrane V0 proton pore complex. This subunit is a non-integral membrane component of the membrane pore domain and is required for proper assembly of the V0 sector. Might be involved in the regulated assembly of V1 subunits onto the membrane sector or alternatively may prevent the passage of protons through V0 pores.
Publication Abstract from PubMed
Eukaryotic vacuolar H(+)-ATPases (V-ATPases) are rotary enzymes that use energy from hydrolysis of ATP to ADP to pump protons across membranes and control the pH of many intracellular compartments. ATP hydrolysis in the soluble catalytic region of the enzyme is coupled to proton translocation through the membrane-bound region by rotation of a central rotor subcomplex, with peripheral stalks preventing the entire membrane-bound region from turning with the rotor. The eukaryotic V-ATPase is the most complex rotary ATPase: it has three peripheral stalks, a hetero-oligomeric proton-conducting proteolipid ring, several subunits not found in other rotary ATPases, and is regulated by reversible dissociation of its catalytic and proton-conducting regions. Studies of ATP synthases, V-ATPases, and bacterial/archaeal V/A-ATPases have suggested that flexibility is necessary for the catalytic mechanism of rotary ATPases, but the structures of different rotational states have never been observed experimentally. Here we use electron cryomicroscopy to obtain structures for three rotational states of the V-ATPase from the yeast Saccharomyces cerevisiae. The resulting series of structures shows ten proteolipid subunits in the c-ring, setting the ATP:H(+) ratio for proton pumping by the V-ATPase at 3:10, and reveals long and highly tilted transmembrane alpha-helices in the a-subunit that interact with the c-ring. The three different maps reveal the conformational changes that occur to couple rotation in the symmetry-mismatched soluble catalytic region to the membrane-bound proton-translocating region. Almost all of the subunits of the enzyme undergo conformational changes during the transitions between these three rotational states. The structures of these states provide direct evidence that deformation during rotation enables the smooth transmission of power through rotary ATPases.
Electron cryomicroscopy observation of rotational states in a eukaryotic V-ATPase.,Zhao J, Benlekbir S, Rubinstein JL Nature. 2015 May 14;521(7551):241-5. doi: 10.1038/nature14365. PMID:25971514[8]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Gimble FS, Thorner J. Homing of a DNA endonuclease gene by meiotic gene conversion in Saccharomyces cerevisiae. Nature. 1992 May 28;357(6376):301-6. PMID:1534148 doi:http://dx.doi.org/10.1038/357301a0
- ↑ Gimble FS, Thorner J. Homing of a DNA endonuclease gene by meiotic gene conversion in Saccharomyces cerevisiae. Nature. 1992 May 28;357(6376):301-6. PMID:1534148 doi:http://dx.doi.org/10.1038/357301a0
- ↑ Kawasaki-Nishi S, Nishi T, Forgac M. Yeast V-ATPase complexes containing different isoforms of the 100-kDa a-subunit differ in coupling efficiency and in vivo dissociation. J Biol Chem. 2001 May 25;276(21):17941-8. Epub 2001 Mar 2. PMID:11278748 doi:http://dx.doi.org/10.1074/jbc.M010790200
- ↑ Manolson MF, Proteau D, Jones EW. Evidence for a conserved 95-120 kDa subunit associated with and essential for activity of V-ATPases. J Exp Biol. 1992 Nov;172:105-12. PMID:1491220
- ↑ Leng XH, Manolson MF, Liu Q, Forgac M. Site-directed mutagenesis of the 100-kDa subunit (Vph1p) of the yeast vacuolar (H+)-ATPase. J Biol Chem. 1996 Sep 13;271(37):22487-93. PMID:8798414
- ↑ Yamashiro CT, Kane PM, Wolczyk DF, Preston RA, Stevens TH. Role of vacuolar acidification in protein sorting and zymogen activation: a genetic analysis of the yeast vacuolar proton-translocating ATPase. Mol Cell Biol. 1990 Jul;10(7):3737-49. PMID:2141385
- ↑ Parra KJ, Keenan KL, Kane PM. The H subunit (Vma13p) of the yeast V-ATPase inhibits the ATPase activity of cytosolic V1 complexes. J Biol Chem. 2000 Jul 14;275(28):21761-7. PMID:10781598 doi:http://dx.doi.org/10.1074/jbc.M002305200
- ↑ Zhao J, Benlekbir S, Rubinstein JL. Electron cryomicroscopy observation of rotational states in a eukaryotic V-ATPase. Nature. 2015 May 14;521(7551):241-5. doi: 10.1038/nature14365. PMID:25971514 doi:http://dx.doi.org/10.1038/nature14365
