Specific plasma membrane differentiations in the cells of the kidney collecting tubule

Humbert, F; Pricam, C; Perrelet, Alain; Orci, Lelio

doi:10.1016/s0022-5320(75)80018-9

Cited by 103 publications

(30 citation statements)

References 12 publications

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“…RSPs have long been associated with the V-ATPase in a variety of cell types (15,16,29,43,56), although whether they actually represent V-ATPase transmembrane domains has never been definitively proven. The similar appearance of RSPs in both wild-type and B1-deficient mice indicates that their morphology is not related to the presence of a particular B subunit isoform.…”

Section: Discussionmentioning

confidence: 99%

“…It has been demonstrated previously that plasma membranes and intracellular vesicles from proton-secreting cells, including renal ICs, contain a highly characteristic class of IMPs known as "rodshaped particles" (RSPs) (15,29,43,56). Based on their appearance in membranes with high V-ATPase content, they are believed to represent transmembrane domains of the VATPase (16).…”

Section: Freeze-fracture Analysis Of A-ic Membranesmentioning

confidence: 99%

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Compensatory membrane expression of the V-ATPase B2 subunit isoform in renal medullary intercalated cells of B1-deficient mice

Păunescu

Russo

Silva

et al. 2007

American Journal of Physiology-Renal Physiology

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Compensatory membrane expression of the V-ATPase B2 subunit isoform in renal medullary intercalated cells of B1-deficient mice. Am J Physiol Renal Physiol 293: F1915-F1926, 2007. First published September 26, 2007; doi:10.1152/ajprenal.00160.2007.-Mice deficient in the ATP6V1B1 ("B1") subunit of the vacuolar protonpumping ATPase (V-ATPase) maintain body acid-base homeostasis under normal conditions, but not when exposed to an acid load. Here, compensatory mechanisms involving the alternate ATP6V1B2 ("B2") isoform were examined to explain the persistence of baseline pH regulation in these animals. By immunocytochemistry, the mean pixel intensity of apical B2 immunostaining in medullary A intercalated cells (A-ICs) was twofold greater in B1Ϫ/Ϫ mice than in B1ϩ/ϩ animals, and B2 was colocalized with other V-ATPase subunits. No significant upregulation of B2 mRNA or protein expression was detected in B1Ϫ/Ϫ mice compared with wild-type controls. We conclude that increased apical B2 staining is due to relocalization of B2-containing V-ATPase complexes from the cytosol to the plasma membrane. Recycling of B2-containing holoenzymes between these domains was confirmed by the intracellular accumulation of B1-deficient V-ATPases in response to the microtubule-disrupting drug colchicine. V-ATPase membrane expression is further supported by the presence of "rod-shaped" intramembranous particles seen by freeze fracture microscopy in apical membranes of normal and B1-deficient A-ICs. Intracellular pH recovery assays show that significant (28 -40% of normal) V-ATPase function is preserved in medullary ICs from B1Ϫ/Ϫ mice. We conclude that the activity of apical B2-containing V-ATPase holoenzymes in A-ICs is sufficient to maintain baseline acid-base homeostasis in B1-deficient mice. However, our results show no increase in cell surface V-ATPase activity in response to metabolic acidosis in ICs from these animals, consistent with their inability to appropriately acidify their urine under these conditions. proton pump; immunofluorescence; pH homeostasis; urinary acidification; Atp6v1b1Ϫ/Ϫ mice THE MAIN MEDIATOR OF INTRACELLULAR organelle acidification in eukaryotic cells and of proton (H ϩ ) secretion along the distal renal nephron is the ubiquitous vacuolar proton-pumping ATPase (vacuolar, or V-type, H ϩ -ATPase, or V-ATPase). The V-ATPase is a complex enzyme, consisting of two large sectors or domains (V 0 , the transmembrane domain involved in H ϩ translocation, and V 1 , the cytosolic domain, responsible for hydrolyzing ATP), which together contain at least 13 distinct

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Section: Discussionmentioning

confidence: 99%

Section: Freeze-fracture Analysis Of A-ic Membranesmentioning

confidence: 99%

Compensatory membrane expression of the V-ATPase B2 subunit isoform in renal medullary intercalated cells of B1-deficient mice

Păunescu

Russo

Silva

et al. 2007

American Journal of Physiology-Renal Physiology

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“…Concave and convex membrane faces were either devoid of particles or contained few particles which were often arranged in clus ters. The particles measured 5 to 15 nm and are therefore consistent with IMPs described for membranes in general [Branton ct al., 1975;Humbert et al, 1975;Pinto da Silva, 1979;Schiller and Taugner, 1980;K rizetal., 1981;Katchburian and Severs, 1982;Arancia. 1983;Tesarik.…”

Section: Discussionmentioning

confidence: 99%

Unusual Membrane-Bound Bodies in the Basal Lamina of the Uriniferous Tubules of the Camel <i>Camelus dromedarius</i>

Safer¹,

Katchburian²

1991

Cells Tissues Organs

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Kidney samples of the camel Camelus dromedarius were aldehyde fixed and glycerol impregnated for ultrathin-section and freeze-fracture studies of the basal lamina. Results obtained show the presence of extracellular membrane-bound bodies within the thick basal lamina of the tubular portion of the nephron. The 10- to 500-nm bodies appear isolated and are found at various levels along the width of a highly structural lattice basal lamina. The bodies are observed either in small groups or as single structures which are invariably surrounded by a clear halo of the basal lamina. In ultrathin sections they appear limited by a typical unit-membrane structure, and their interior may appear empty or may exhibit material of variable electron opacity. Freeze-fracture replicas reveal the limiting membrane of the bodies which appear either as concave or convex structures. Intramembrane particles (IMPs) measuring between 5 and 15 nm are present in some of the bodies whilst others appear devoid of IMPs. The IMPs are present in both concave and convex surfaces and are usually aggregated into clumps. The region of the basal lamina which contains the membrane-bound bodies is usually granular except in the area immediately surrounding the bodies which corresponds to the clear halo observed in thin sections. Although these basal lamina membrane-bound bodies appear to be similar to matrix vesicles previously described in mineralizing tissues, it seems unlikely that they are involved in calcification. It is possible that the membrane-bound bodies and the highly configurated basal lamina may be related to ionic transport mechanisms which are associated with the high osmolarity of the camel urine.

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“…AQP4 was the first aquaporin to be observed and identified in biological membranes, because when examined by freeze-fracture electron microscopy, it forms characteristic arrays of intramembraneous particles (IMPs) in the form of checkerboard aggregates or orthogonal arrays of intramembraneous particles (OAPs). These OAPs were described in various cell membranes long before a role in water permeability was suspected (3,18,27,31,32). The relationship of OAPs to water channels was first suggested by earlier studies showing that membranes that contained OAPs, including astrocytes, gastric parietal cells, and collecting duct principal cells were immunostained by an antibody raised against the whole AQP1 (then called CHIP28) protein (37).…”

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confidence: 99%

Membrane organization and function of M1 and M23 isoforms of aquaporin-4 in epithelial cells

Silberstein¹,

Bouley²,

Huang³

et al. 2004

American Journal of Physiology-Renal Physiology

142

145

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(AQP4) water channels exist as heterotetramers of M1 and M23 splice variants and appear to be present in orthogonal arrays of intramembraneous particles (OAPs) visualized by freeze-fracture microscopy. We report that AQP4 forms OAPs in rat gastric parietal cells but not in parietal cells from the mouse or kangaroo rat. Furthermore, the organization of principal cell OAPs in Brattleboro rat kidney is perturbed by vasopressin (arginine vasopressin). Membranes of LLC-PK1 cells expressing M23-AQP4 showed large, abundant OAPs, but none were detectable in cells expressing M1-AQP4. Measurements of osmotic swelling of transfected LLC-PK1 cells using videomicroscopy, gave osmotic water permeability coefficient (Pf) values (in cm/s) of 0.018 (M1-AQP4), 0.019 (M23-AQP4), and 0.003 (control). Quantitative immunoblot and immunofluorescence showed an eightfold greater expression of M1-over M23-AQP4 in the cell lines, suggesting that single-channel pf (cm 3 /s) is much greater for the M23 variant. Somatic fusion of M1-and M23-AQP4 cells (Pf ϭ 0.028 cm/s) yielded OAPs that were fewer and smaller than in M23 cells alone, and M1-to-M23 expression ratios (ϳ1:4) normalized to AQP4 in M1 or M23 cells indicated a reduced single-channel pf for the M23 variant. Expression of an M23-AQP4-Ser 111E mutant produced ϳ1.5-fold greater single-channel pf and OAPs that were up to 2.5-fold larger than wild-type M23-AQP4 OAPs, suggesting that a putative PKA phosphorylation site Ser 111 is involved in OAP formation. We conclude that the higher-order organization of AQP4 in OAPs increases single-channel osmotic water permeability by one order of magnitude and that differential cellular expression levels of the two isoforms could regulate this organization. water transport; freeze-fracture; LLC-PK1 cells; orthogonal arrays; intramembraneous particles THE MAMMALIAN FAMILY OF AQUAPORIN water channels consists of 12 known members, each with a specific tissue distribution and membrane localization pattern. However, the role of aquaporin-4 (AQP4) in water transport physiology is not well understood. AQP4 was the first aquaporin to be observed and identified in biological membranes, because when examined by freeze-fracture electron microscopy, it forms characteristic arrays of intramembraneous particles (IMPs) in the form of checkerboard aggregates or orthogonal arrays of intramembraneous particles (OAPs). These OAPs were described in various cell membranes long before a role in water permeability was suspected (3,18,27,31,32). The relationship of OAPs to water channels was first suggested by earlier studies showing that membranes that contained OAPs, including astrocytes, gastric parietal cells, and collecting duct principal cells were immunostained by an antibody raised against the whole AQP1 (then called CHIP28) protein (37). A different antibody raised against skeletal muscle OAP-containing membranes also recognized an ϳ30-kDa protein in these membranes (15,41). In this way, a protein initially called basolateral intrinsic membrane protein (BLIP) was ...

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Specific plasma membrane differentiations in the cells of the kidney collecting tubule

Cited by 103 publications

References 12 publications

Compensatory membrane expression of the V-ATPase B2 subunit isoform in renal medullary intercalated cells of B1-deficient mice

Compensatory membrane expression of the V-ATPase B2 subunit isoform in renal medullary intercalated cells of B1-deficient mice

Unusual Membrane-Bound Bodies in the Basal Lamina of the Uriniferous Tubules of the Camel <i>Camelus dromedarius</i>

Membrane organization and function of M1 and M23 isoforms of aquaporin-4 in epithelial cells

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