Reversible microsomal binding of hepatic aldolase

Weiss, Tania L.; Zieske, James D.; Bernstein, Isadore A.

doi:10.1016/0005-2744(81)90007-3

Cited by 9 publications

(9 citation statements)

References 36 publications

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“…20 µM and 40 µM, respectively). This is consistent with a previous study on the muscle isoenzyme [9] but not with findings on the binding of liver aldolase to the microsomal fraction, where 11 mM dihydroxyacetone did not cause dissociation [17]. The lack of additive effects of fructose 1,6-bisphosphate and triose phosphates on aldolase dissociation from permeabilized hepatocytes suggests that even if there are different pools of bound aldolase, the total bound fraction appears to be dissociated by both metabolites.…”

Section: Discussionsupporting

confidence: 90%

“…The similar changes in activity assayed with fructose 1,6bisphosphate and fructose 1-phosphate suggest that the enzyme released in the absence and presence of 5 mM MgCl # is unlikely to represent different isoenzymes. This is consistent with evidence that aldolase B is the only isoenzyme expressed in liver [17].…”

Section: Effects Of Digitonin Concentration On Aldolase Releasesupporting

confidence: 92%

“…There is evidence that hepatic aldolase binds to the nucleus [15] and endoplasmic reticulum [16,17]. Studies on Swiss 3T3 fibroblasts microinjected with aldolase A showed that there was an ' immobile ' fraction in the perinuclear region and a mobile or free phase throughout the cytoplasm but with a lower diffusion coefficient in the perinuclear region than in the cell periphery, which is consistent with a higher cytoplasmic viscosity in the perinuclear region [35,36].…”

Section: Possible Locations Of Aldolase Binding and Physiological Rolementioning

confidence: 80%

“…The A-isoenzyme in erythrocytes binds to band-3 on the plasma membrane [12]. The C-isoenzyme binds to brain homogenates [13,14] and the B-isoenzyme binds to the nucleus [15] and endoplasmic reticulum [16,17]. Binding of aldolase to different subcellular structures or proteins is of interest because the affinity of the enzyme for its substrate is altered by binding to filamentous actin and glyceraldehyde-3-phosphate dehydrogenase [9,10].…”

Section: Introductionmentioning

confidence: 99%

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Substrate modulation of aldolase B binding in hepatocytes

Agius

1996

Biochemical Journal

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The binding properties of hepatic aldolase (B) were determined in digitonin-permeabilized rat hepatocytes after the cells had been preincubated with either glycolytic or gluconeogenic substrates. In hepatocytes that had been preincubated in medium containing 5 mM glucose as sole carbohydrate substrate, binding of aldolase to the hepatocyte matrix was maximal at low KCl concentrations (20 mM) or bivalent cation concentrations (1 mM Mg2+) and half-maximal dissociation occurred at 50 mM KCl. Preincubation of hepatocytes (for 10-30 min) with glucose or mannose (10-40 mM), fructose, sorbitol, dihydroxyacetone or glycerol (1-10 mM), caused a leftward shift of the salt dissociation curve (maximum binding at 10 mM KCl; half-maximum dissociation at 35 mM KCl) but did not affect the proportion of bound enzyme at low or high KCl concentrations. Galactose and 2-deoxyglucose had no effect on aldolase binding. Inhibitors of glucokinase (mannoheptulose and glucosamine) suppressed the effects of glucose but not the effects of sorbitol, glycerol or dihydroxyacetone. Glucagon suppressed the effects of glucose, fructose and dihydroxyacetone but not glycerol. Poly(ethylene glycol) (PEG) (2-10%), added to the permeabilization medium, increased aldolase binding and caused a rightward shift in the salt dissociation curve. In the presence of PEG (6-8%), the effects of substrates on aldolase dissociation were shifted to higher salt concentrations (50-100 mM versus 35 mM KCl). The effects of substrates (added to the intact cell) on aldolase binding to the permeabilized cell could be mimicked by addition of the phosphorylated derivatives of these substrates to the permeabilized cell. Of the intermediates tested dihydroxyacetone phosphate and fructose 1,6-bisphosphate were the most effective at dissociating aldolase (A50 values of 20 microM and 40 microM respectively). Other effective intermediates in order of decreasing potency were fructose 1-phosphate, glycerol 3-phosphate, glucose 1,6-bisphosphate/fructose 2,6-bisphosphate. These results show that aldolase B binds to the hepatocyte matrix by a salt-dependent mechanism that is influenced by macromolecular crowding and metabolic intermediates. Maximum binding occurs when hepatocytes are incubated in the absence of glycolytic and gluconeogenic substrates and minimum binding occurs in the presence of substrates that are precursors of either fructose 1,6-bisphosphate or triose phosphates. Since the bound form of aldolase represents a kinetically less active state it is proposed that aldolase binding and dissociation may be a mechanism for buffering the concentrations of metabolic intermediates.

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Section: Discussionsupporting

confidence: 90%

Section: Effects Of Digitonin Concentration On Aldolase Releasesupporting

confidence: 92%

Section: Possible Locations Of Aldolase Binding and Physiological Rolementioning

confidence: 80%

Section: Introductionmentioning

confidence: 99%

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Substrate modulation of aldolase B binding in hepatocytes

Agius

1996

Biochemical Journal

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“…Both substrates and products of aldolase, as well as inositol 1,4,5-trisphosphate (44,45), inhibit its binding to actin (36,46). In hepatocytes, aldolase is thought to be largely bound to the cytoskeleton and inactive during fasting.…”

Section: Fig 5 In Vivo Interaction Between V-atpase and Aldolasementioning

confidence: 99%

Interaction between Aldolase and Vacuolar H+-ATPase

Lu¹,

Holliday²,

Zhang³

et al. 2001

Journal of Biological Chemistry

173

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Vacuolar H؉ -ATPases (V-ATPases) are essential for acidification of intracellular compartments and for proton secretion from the plasma membrane in kidney epithelial cells and osteoclasts. The cellular proteins that regulate V-ATPases remain largely unknown. A screen for proteins that bind the V-ATPase E subunit using the yeast two-hybrid assay identified the cDNA clone coded for aldolase, an enzyme of the glycolytic pathway. The interaction between E subunit and aldolase was confirmed in vitro by precipitation assays using E subunit-glutathione S-transferase chimeric fusion proteins and metabolically labeled aldolase. Aldolase was isolated associated with intact V-ATPase from bovine kidney microsomes and osteoclast-containing mouse marrow cultures in co-immunoprecipitation studies performed using an anti-E subunit monoclonal antibody. The interaction was not affected by incubation with aldolase substrates or products. In immunocytochemical assays, aldolase was found to colocalize with V-ATPase in the renal proximal tubule. In osteoclasts, the aldolase-V-ATPase complex appeared to undergo a subcellular redistribution from perinuclear compartments to the ruffled membranes following activation of resorption. In yeast cells deficient in aldolase, the peripheral V 1 domain of V-ATPase was found to dissociate from the integral membrane V 0 domain, indicating direct coupling of glycolysis to the proton pump. The direct binding interaction between V-ATPase and aldolase may be a new mechanism for the regulation of the V-ATPase and may underlie the proximal tubule acidification defect in hereditary fructose intolerance. Vacuolar Hϩ -ATPases (V-ATPases) 1 are large multisubunit proteins that are evolutionarily related and structurally similar to the F-ATPases (for a review, see Ref. 1). V-ATPases function in the acidification of a variety of intracellular compartments in eukaryotic cells (2) and in proton secretion from the plasma membrane of some specialized cells in higher organisms (3, 4). V-ATPases are required for maintaining the acidity of endosomes, lysosomes, Golgi-derived vesicles, chromaffin granules, the central vacuoles of yeast and plants, and some clathrin-coated vesicles (2). In some specific cells of the proximal tubule and collecting duct of the kidney, V-ATPases are present at high densities on the plasma membrane and have a central role in maintaining the acid-base balance of the organism (3). In osteoclasts, cells that are essential for bone remodeling, densely packed V-ATPases reside in a specialized domain of the apical plasma membrane known as the ruffled membrane, where they acidify an extracellular compartment at the site of attachment to bone (5). Osteoclast proton secretion is required both for dissolution of bone mineral and for efficient degradation of bone matrix proteins by acid cysteine proteinases (6).During the past decade, much effort has been devoted to isolating genes that encode the subunits of V-ATPases, determining how V-ATPase genes are regulated, and identifying interactions among...

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Similarities in properties, content, and relative rates of synthesis of fructose-P2 aldolase in livers of fed and starved rats

1983

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The present work gives evidence that, in contrast to the situation reported by Pontremoli et al. for the rabbit (Proc, Natl. Acad. Sci. U.S.A. 76, 6323-6325, 1979; Arch. Biochem. Biophys. 203, 390-394, 1980; Proc. Natl. Acad. Sci. U.S.A, 79, 5194-5196, 1982), starvation for as long as 3 days does not cause intracellular covalent modification and inactivation of fructose-P2 aldolase molecules in rat liver cells. This conclusion is based on our observations that liver aldolase molecules isolated from fed and starved rats in the presence of proteolytic inhibitors were not distinguished on the basis of specific catalytic activity, electrophoretic mobility, subunit molecular weight, NH2-terminal structure, or COOH-terminal structure. Further, the approximate 40% loss in rat liver mass which occurred during the 3-day fast was not associated with appreciable changes in the content of aldolase and most other abundant cytosolic proteins per gram of rat liver, as judged by electrophoretic analysis of 100 000-g soluble fractions of liver extracts. Finally, a 3-day fast had no appreciable effect on the relative rates of synthesis of aldolase and most other abundant cytosolic proteins in rat liver. Our findings suggest that nutrient deprivation has no preferential effect on the concentration or metabolism of aldolase in rat liver cells.

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Reversible microsomal binding of hepatic aldolase

Cited by 9 publications

References 36 publications

Substrate modulation of aldolase B binding in hepatocytes

Substrate modulation of aldolase B binding in hepatocytes

Interaction between Aldolase and Vacuolar H+-ATPase

Similarities in properties, content, and relative rates of synthesis of fructose-P2 aldolase in livers of fed and starved rats

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