Acidification and Bone Resorption: The Role and Characteristics of V-ATPases in the Osteoclast

Baron, Roland; Bartkiewicz, Marcjanna; David, P.; Hernando-Sobrino, Natividad

doi:10.1007/978-3-662-22265-2_3

Cited by 4 publications

(6 citation statements)

References 62 publications

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“…V-ATPase is rich in endosomes as well as luminal plasma membrane, similar to the V-ATPase localization in other epithelial cells [5][6][7]. To our knowledge, this is the first report showing the presence of electrolyte transporter in the mammalian urinary bladder.…”

Section: Immunohistochemical Detection Of V-atpasesupporting

confidence: 67%

“…V-ATPases present in plasma membrane may acidify extracellular spaces in osteoclast, collecting ducts in kidney, phagocytes and insect midgut [5][6][7]. Thus, it is expected that a similar mechanism operates in the urinary acidification in the bladder.…”

Section: Immunohistochemical Detection Of V-atpasementioning

confidence: 99%

“…In some epithelial cells, VATPases are abundant at the plasma membrane, extrude protons, and acidify the restricted extracellular space. Examples of the requirement of extracellular acidification are bone resorption in osteoclast and nutrient absorption in insect midgut (reviewed in [5][6][7]). The mechanism of urinary acidification and ion transport has been studied extensively (reviewed in [5,8,9]).…”

Section: Introductionmentioning

confidence: 99%

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Vacuolar‐type H⁺‐ATPase in mouse bladder epithelium is responsible for urinary acidification

et al. 1997

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Section: Immunohistochemical Detection Of V-atpasesupporting

confidence: 67%

Section: Immunohistochemical Detection Of V-atpasementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Vacuolar‐type H⁺‐ATPase in mouse bladder epithelium is responsible for urinary acidification

et al. 1997

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“…Osteoclasts are specialized tissue macrophages that reside in bone; these cells are polarized, having apical and basolateral regions (12). They reabsorb mineralized bone by attaching to bone matrix and forming a tight ringlike zone of adhesion, the "sealing zone."…”

Section: F V-atpases Drive Bone Resorption In Mammalian Osteoclastsmentioning

confidence: 99%

“…The structure, function, biogenesis, and regulation of V-ATPases have been recently reviewed (182), and two books were published on V-ATPase (82,155). Recent reviews also emphasize plasma membrane V-ATPases and specialized functions in plants, microorganisms, and mammalian systems (12,22,46,60,70,119,156,196,219). However, we still do not know how V-ATPases couple ATP hydrolysis to H ϩ pumping, nor do we understand how the many subunits of the membrane and catalytic sectors are assembled.…”

Section: Introductionmentioning

confidence: 99%

Vacuolar and Plasma Membrane Proton-Adenosinetriphosphatases

Nelson

Harvey²

1999

Physiological Reviews

392

338

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The vacuolar H+-ATPase (V-ATPase) is one of the most fundamental enzymes in nature. It functions in almost every eukaryotic cell and energizes a wide variety of organelles and membranes. V-ATPases have similar structure and mechanism of action with F-ATPase and several of their subunits evolved from common ancestors. In eukaryotic cells, F-ATPases are confined to the semi-autonomous organelles, chloroplasts, and mitochondria, which contain their own genes that encode some of the F-ATPase subunits. In contrast to F-ATPases, whose primary function in eukaryotic cells is to form ATP at the expense of the proton-motive force (pmf), V-ATPases function exclusively as ATP-dependent proton pumps. The pmf generated by V-ATPases in organelles and membranes of eukaryotic cells is utilized as a driving force for numerous secondary transport processes. The mechanistic and structural relations between the two enzymes prompted us to suggest similar functional units in V-ATPase as was proposed to F-ATPase and to assign some of the V-ATPase subunit to one of four parts of a mechanochemical machine: a catalytic unit, a shaft, a hook, and a proton turbine. It was the yeast genetics that allowed the identification of special properties of individual subunits and the discovery of factors that are involved in the enzyme biogenesis and assembly. The V-ATPases play a major role as energizers of animal plasma membranes, especially apical plasma membranes of epithelial cells. This role was first recognized in plasma membranes of lepidopteran midgut and vertebrate kidney. The list of animals with plasma membranes that are energized by V-ATPases now includes members of most, if not all, animal phyla. This includes the classical Na+ absorption by frog skin, male fertility through acidification of the sperm acrosome and the male reproductive tract, bone resorption by mammalian osteoclasts, and regulation of eye pressure. V-ATPase may function in Na+ uptake by trout gills and energizes water secretion by contractile vacuoles in Dictyostelium. V-ATPase was first detected in organelles connected with the vacuolar system. It is the main if not the only primary energy source for numerous transport systems in these organelles. The driving force for the accumulation of neurotransmitters into synaptic vesicles is pmf generated by V-ATPase. The acidification of lysosomes, which are required for the proper function of most of their enzymes, is provided by V-ATPase. The enzyme is also vital for the proper function of endosomes and the Golgi apparatus. In contrast to yeast vacuoles that maintain an internal pH of ∼5.5, it is believed that the vacuoles of lemon fruit may have a pH as low as 2. Similarly, some brown and red alga maintain internal pH as low as 0.1 in their vacuoles. One of the outstanding questions in the field is how such a conserved enzyme as the V-ATPase can fulfill such diverse functions.

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Secretion of L-glutamate from osteoclasts through transcytosis

Morimoto

Uehara

Yatsushiro

et al. 2006

EMBO J

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Osteoclasts are involved in the catabolism of the bone matrix and eliminate the resulting degradation products through transcytosis, but the molecular mechanism and regulation of transcytosis remain poorly understood. Upon differentiation, osteoclasts express vesicular glutamate transporter 1 (VGLUT1), which is essential for vesicular storage and subsequent exocytosis of glutamate in neurons. VGLUT1 is localized in transcytotic vesicles and accumulates L‐glutamate. Osteoclasts secrete L‐glutamate and the bone degradation products upon stimulation with KCl or ATP in a Ca2+‐dependent manner. KCl‐ and ATP‐dependent secretion of L‐glutamate was absent in osteoclasts prepared from VGLUT1−/− knockout mice. Osteoclasts express mGluR8, a class III metabotropic glutamate receptor. Its stimulation by a specific agonist inhibits secretion of L‐glutamate and bone degradation products, whereas its suppression by a specific antagonist stimulates bone resorption. Finally, it was found that VGLUT1−/− mice develop osteoporosis. Thus, in bone‐resorbing osteoclasts, L‐glutamate and bone degradation products are secreted through transcytosis and the released L‐glutamate is involved in autoregulation of transcytosis. Glutamate signaling may play an important role in the bone homeostasis.

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Acidification and Bone Resorption: The Role and Characteristics of V-ATPases in the Osteoclast

Cited by 4 publications

References 62 publications

Vacuolar‐type H⁺‐ATPase in mouse bladder epithelium is responsible for urinary acidification

Vacuolar‐type H⁺‐ATPase in mouse bladder epithelium is responsible for urinary acidification

Vacuolar and Plasma Membrane Proton-Adenosinetriphosphatases

Secretion of L-glutamate from osteoclasts through transcytosis

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Acidification and Bone Resorption: The Role and Characteristics of V-ATPases in the Osteoclast

Cited by 4 publications

References 62 publications

Vacuolar‐type H+‐ATPase in mouse bladder epithelium is responsible for urinary acidification

Vacuolar‐type H+‐ATPase in mouse bladder epithelium is responsible for urinary acidification

Vacuolar and Plasma Membrane Proton-Adenosinetriphosphatases

Secretion of L-glutamate from osteoclasts through transcytosis

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Product

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Vacuolar‐type H⁺‐ATPase in mouse bladder epithelium is responsible for urinary acidification

Vacuolar‐type H⁺‐ATPase in mouse bladder epithelium is responsible for urinary acidification