Caveolar Structure and Protein Sorting Are Maintained in NIH 3T3 Cells Independent of Glycosphingolipid Depletion

Shu, Liming; Lee, Lishueh; Chang, Yan; Holzman, Lawrence B.; Edwards, Chris; Shelden, Eric A.; Shayman, James A.

doi:10.1006/abbi.1999.1553

Cited by 28 publications

(26 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…14 A decrease of sphingomyelin content under hypoxia has also been reported, 37 but the effect of sphingomyelin on the sorting of GPI-anchored proteins is controversial. 18,38 In contrast with these studies, nonesterified cholesterol content, measured by GC-MS, was not modified in hypoxic SVARECs. Furthermore, addition of 50 g/mL LDL-cholesterol 24 hours before the 18-hour period of hypoxia did not reverse the increase of Ecto-5Ј-Nu membrane expression.…”

Section: Effect Of Hypoxia On Membrane Lipid Compositioncontrasting

confidence: 65%

Hypoxia Enhances Ecto-5′-Nucleotidase Activity and Cell Surface Expression in Endothelial Cells

Ledoux

Runembert

Koumanov

et al. 2003

Circulation Research

View full text Add to dashboard Cite

Abstract-Extracellular adenosine production by the glycosyl-phosphatidyl-inositol-anchored Ecto-5Ј-Nucleotidase plays an important role in the defense against hypoxia, particularly in the intravascular space. The present study was designed in order to elucidate the mechanisms underlying hypoxia-induced stimulation of Ecto-5Ј-Nucleotidase in endothelial cells. For this purpose, aortic endothelial cells (SVARECs) were submitted to hypoxic gas mixture. Hypoxia (0% O 2 for 18 hours) induced a 2-fold increase of Ecto-5Ј-Nucleotidase activity (V max 19.78Ϯ0.53 versus 8.82Ϯ1.12 nmol/mg protein per min), whereas mRNA abundance and total amount of the protein were unmodified. By contrast, hypoxia enhanced cell surface expression of Ecto-5Ј-Nucleotidase, as evidenced both by biotinylation and immunostaining. This effect was accompanied by a decrease of Ecto-5Ј-Nucleotidase endocytosis, without modification of Ecto-5Ј-Nucleotidase association with detergent-resistant membranes. Finally, whereas cholesterol content was unmodified, hypoxia induced a time-dependent increase of saturated fatty acids in SVARECs, which was reversed by reoxygenation, in parallel to Ecto-5Ј-Nucleotidase stimulation. Incubation of normoxic cells with palmitic acid enhanced Ecto-5Ј-Nucleotidase activity and cell surface expression. In conclusion, hypoxia enhances cell surface expression of Ecto-5Ј-Nucleotidase in endothelial cells. This effect could be supported by a decrease of Ecto-5Ј-Nucleotidase endocytosis through modification of plasma membrane fatty acid composition.

show abstract

Section: Effect Of Hypoxia On Membrane Lipid Compositioncontrasting

confidence: 65%

Hypoxia Enhances Ecto-5′-Nucleotidase Activity and Cell Surface Expression in Endothelial Cells

Ledoux

Runembert

Koumanov

et al. 2003

Circulation Research

View full text Add to dashboard Cite

show abstract

“…(E) Untreated. cant changes in the distribution of proteins (Shu et al, 2000). Therefore, the role of GSL in affecting DRM association of other constituents seems to be highly specific.…”

Section: Discussionmentioning

confidence: 99%

The Association of Shiga-like Toxin with Detergent-resistant Membranes Is Modulated by Glucosylceramide and Is an Essential Requirement in the Endoplasmic Reticulum for a Cytotoxic Effect

Smith

Sillence

Jarvis

et al. 2006

MBoC

103

View full text Add to dashboard Cite

Receptor-mediated internalization to the endoplasmic reticulum (ER) and subsequent retro-translocation to the cytosol are essential sequential processes required for the productive intoxication of susceptible mammalian cells by Shiga-like toxin-1 (SLTx). Recently, it has been proposed that the observed association of certain ER-directed toxins and viruses with detergent-resistant membranes (DRM) may provide a general mechanism for their retrograde transport to endoplasmic reticulum (ER). Here, we show that DRM recruitment of SLTx bound to its globotriosylceramide (Gb 3 ) receptor is mediated by the availability of other glycosphingolipids. Reduction in glucosylceramide (GlcCer) levels led to complete protection against SLTx and a reduced cell surface association of bound toxin with DRM. This reduction still allowed efficient binding and transport of the toxin to the ER. However, toxin sequestration within DRM of the ER was abolished under reduced GlcCer conditions, suggesting that an association of toxin with lipid microdomains or rafts in the ER (where these are defined by detergent insolubility) is essential for a later step leading to or involving retro-translocation of SLTx across the ER membrane. In support of this, we show that a number of ER residents, proteins intimately involved in the process of ER dislocation of misfolded proteins, are present in DRM.

show abstract

“…Protein concentrations were determined by use of the bicinchoninic acid assay using bovine serum albumin as a standard. Immunoprecipitation and immunoblots were performed as previously described (13). Briefly, equal amounts of protein from each cell lysate were incubated with selected antibodies at 4°C for 2 h or subjected to direct Western blotting.…”

Section: Methodsmentioning

confidence: 99%

Src Kinase Mediates the Regulation of Phospholipase C-γ Activity by Glycosphingolipids

Shu

Shayman

2003

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Caveolar Structure and Protein Sorting Are Maintained in NIH 3T3 Cells Independent of Glycosphingolipid Depletion

Cited by 28 publications

References 28 publications

Hypoxia Enhances Ecto-5′-Nucleotidase Activity and Cell Surface Expression in Endothelial Cells

Hypoxia Enhances Ecto-5′-Nucleotidase Activity and Cell Surface Expression in Endothelial Cells

The Association of Shiga-like Toxin with Detergent-resistant Membranes Is Modulated by Glucosylceramide and Is an Essential Requirement in the Endoplasmic Reticulum for a Cytotoxic Effect

Src Kinase Mediates the Regulation of Phospholipase C-γ Activity by Glycosphingolipids

Contact Info

Product

Resources

About