Hypotonicity-induced Exocytosis of the Skate Anion Exchanger skAE1

Musch, Mark W.; Koomoa, Dana-Lynn T.; Goldstein, Léon

doi:10.1074/jbc.m405363200

Cited by 18 publications

(15 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar expression pattern for flotillin was reported when PC12 cells were cultured in vitro (28). Expression pattern of flotillins and caveolins in type I and II cells might reflect the specific roles of these proteins in different cells, although there are a number of cells expressing both caveolins and flotillins, such as skate erythrocytes (29) and neonatal rat cardiomyocytes (30). In addition, flotillin-1 and -2 were enriched on the plasma membrane and lamellar bodies, indicating their possible roles in membrane trafficking.…”

Section: Discussionsupporting

confidence: 70%

Effect of Cholesterol Depletion on Exocytosis of Alveolar Type II Cells

Chintagari

Jin

Wang

et al. 2006

Am J Respir Cell Mol Biol

View full text Add to dashboard Cite

Alveolar epithelial type II cells secrete lung surfactant via exocytosis. Soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNARE) are implicated in this process. Lipid rafts, the cholesterol-and sphingolipid-rich microdomains, may offer a platform for protein organization on the cell membrane. We tested the hypothesis that lipid rafts organize exocytotic proteins in type II cells and are essential for the fusion of lamellar bodies, the secretory granules of type II cells, with the plasma membrane. The lipid rafts, isolated from type II cells using 1% Triton X-100 and a sucrose gradient centrifugation, contained the lipid raft markers, flotillin-1 and -2, whereas they excluded the nonraft marker, Na ϩ -K ϩ ATPase. SNAP-23, syntaxin 2, and VAMP-2 were enriched in lipid rafts. When type II cells were depleted of cholesterol, the association of SNAREs with the lipid rafts was disrupted and the formation of fusion pore was inhibited. Furthermore, the cholesterol-depleted plasma membrane had less ability to fuse with lamellar bodies, a process mediated by annexin A2. The secretagogue-stimulated secretion of lung surfactant from type II cells was also reduced by methyl-␤-cyclodextrin. When the raft-associated cell surface protein, CD44, was cross-linked using anti-CD44 antibodies, the CD44 clusters were observed. Syntaxin 2, SNAP-23, and annexin A2 co-localized with the CD44 clusters, which were cholesterol dependent. Our results suggested that lipid rafts may form a functional platform for surfactant secretion in alveolar type II cells, and raft integrity was essential for the fusion between lamellar bodies with the plasma membrane.Keywords: alveolar type II cells; lipid rafts; membrane fusion; SNARE proteins; surfactant secretion Lung alveolar epithelium consists of two different types of cells, the cuboidal type II cells and squamous type I cells. Type II cells synthesize, store, and secrete a surface-active lipid-rich substance, the lung surfactant. The released surfactant lines the alveolar epithelium, lowers the surface tension, and thus prevents the collapse of alveoli at end-expiration. Lung surfactant deficiency causes respiratory distress syndrome (RDS) in infants. Type II cells are also involved in defense, injury and repair, and trans-differentiation into type I cells.Lung surfactant, stored in lamellar bodies, is released upon its fusion with the plasma membrane via exocytosis. The formation of fusion pore precedes the release of lamellar body contents. The SNARE (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) hypothesis was proposed to elucidate the mechanisms of membrane fusion during exocytosis. During fusion, the proteins on the plasma membrane (target or t-SNAREs) and vesicles (vesicular or v-SNARE) form a highly stable, hetero-tetrameric SNARE complex. The two coiled-coil domains are contributed by soluble N-ethylmaleimide-sensitive factor attachment protein (SNAP)-25/23 and one each from syntaxin and VAMP (vesicle-associated membrane protein) (1). NSF ...

show abstract

Section: Discussionsupporting

confidence: 70%

Effect of Cholesterol Depletion on Exocytosis of Alveolar Type II Cells

Chintagari

Jin

Wang

et al. 2006

Am J Respir Cell Mol Biol

View full text Add to dashboard Cite

show abstract

“…Other evidence cited in favour of a role for the anionexchanger in volume-sensitive taurine transport in fish red blood cells are the findings that cell swelling increases the binding of DIDS to the band 3 protein and stimulates the phosphorylation of the exchanger [73]: these results could be explained by the fact that cell swelling induces the movement of AE1 from an intracellular pool to the plasma membrane [74]. In addition, it has been reported that osmotic swelling induces the formation of band 3 tetramers in skate erythrocytes [75,76].…”

Section: The Relationship Between Volume-sensitive Taurine Transport mentioning

confidence: 99%

Swelling-Induced Taurine Transport: Relationship with Chloride Channels, Anion-Exchangers and Other Swelling-Activated Transport Pathways

Shennan¹

2008

Cell Physiol Biochem

View full text Add to dashboard Cite

Cells have to regulate their volume in order to survive. Moreover, it is now evident that cell volume per se and the membrane transport processes which regulate it, comprise an important signalling unit. For example, macromolecular synthesis, apoptosis, cell growth and hormone secretion are all influenced by the cellular hydration state. Therefore, a thorough understanding of volume-activated transport processes could lead to new strategies being developed to control the function and growth of both normal and cancerous cells. Cell swelling stimulates the release of ions such as K⁺ and Cl^- together with organic osmolytes, especially the β-amino acid taurine. Despite being the subject of intense research interest, the nature of the volume-activated taurine efflux pathway is still a matter of controversy. On the one hand it has been suggested that osmosensitive taurine efflux utilizes volume-sensitive anion channels whereas on the other it has been proposed that the band 3 anion-exchanger is a swelling-induced taurine efflux pathway. This article reviews the evidence for and against a role of anion channels and exchangers in osmosensitive taurine transport. Furthermore, the distinct possibility that neither pathway is involved in taurine transport is highlighted. The putative relationship between swelling-induced taurine transport and volume-activated anionic amino acid, α-neutral amino acid and K⁺ transport is also examined.

show abstract

“…This appearance is strongly associated with volume expansion under these conditions. 39 AEs are shown to participate in the efflux of solutes during regulatory volume decreases. In particular, AEs appear to contribute to the loss of aurine from red blood cells of a number of species.…”

Section: Various Fish Speciesmentioning

confidence: 99%

Molecular Response to Osmotic Shock

et al. 2007

View full text Add to dashboard Cite

Abstract:The cellular responses of cultured mammalian cells and non-mammalian organisms to changes in osmolarity are discussed. A number of common themes including activation of protein kinase cascades can be observed in a diverse group of organisms. A combination of physiological and transcriptional studies has been performed to identify regulatory factors and proteins that play a causal role in the cellular responses to osmotic changes. These factors may serve as targets for cellular engineering strategies to improve the productivity of cultured mammalian cells, particularly in response to osmotic shock

show abstract

Hypotonicity-induced Exocytosis of the Skate Anion Exchanger skAE1

Cited by 18 publications

References 40 publications

Effect of Cholesterol Depletion on Exocytosis of Alveolar Type II Cells

Effect of Cholesterol Depletion on Exocytosis of Alveolar Type II Cells

Swelling-Induced Taurine Transport: Relationship with Chloride Channels, Anion-Exchangers and Other Swelling-Activated Transport Pathways

Molecular Response to Osmotic Shock

Contact Info

Product

Resources

About