Metabolism and intracellular transport of glycosphingolipids

Schwarzmann, Günter; Sandhoff, Konrad

doi:10.1021/bi00501a001

Cited by 175 publications

(88 citation statements)

References 82 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The curve representing the biosynthesis of G,, was obtained from the second term of Eqn (2). The characteristic times of the production of tritiated water (I,,,,) and of ganglioside catabolism (1,) were estimated to be 23 days and 4 days, respectively.…”

Section: [Sphh218-'h]g (Figs 4 and 5)mentioning

confidence: 99%

“…The other pool of sphingosine, the cell basal pool, came from the catabolism of radioactive sphingolipids in the recycling of sphingosine, and was used for the biosynthesis of the G,, species that mainly contain very long fatty acid chains, the main fibroblast endogenous species of GD3. Administration of the ganglioside species of G,, containing sphinganine or free sphinganine to fibroblasts yielded the G,, species containing mainly very long-chain fatty acids and sphingosine.These results show the possible existence of a pool of ganglioside-derived sphingosine, quite separate from the cell basal pool of sphingosine, suggesting that sphingosine derived from sphingolipid catabolism is reduced to sphinganine before entering the sphingolipid biosynthetic pathway.Keywords: ganglioside ; biosynthesis ; sphingosine ; sphinganine ; recycling.Gangliosides, sialic acid containing glycosphingolipids that are normal components of plasma membranes [I], are biosynthesized in the Golgi apparatus and degraded in the lysosomes [2] to fragments that are recycled for biosynthetic purposes [3-61. Among the ganglioside catabolic fragments, sphingosine has attracted scientific interest and increasing attention.…”

mentioning

confidence: 99%

“…Gangliosides, sialic acid containing glycosphingolipids that are normal components of plasma membranes [I], are biosynthesized in the Golgi apparatus and degraded in the lysosomes [2] to fragments that are recycled for biosynthetic purposes [3-61. Among the ganglioside catabolic fragments, sphingosine has attracted scientific interest and increasing attention.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Metabolic Processing of Gangliosides by Human Fibroblasts in Culture — Formation and Recycling of Separate Pools of Sphingosine

Chigorno

Riva

Valsecchi

et al. 1997

European Journal of Biochemistry

View full text Add to dashboard Cite

Human cultured fibroblasts were fed with G,, ganglioside species isotopically labeled at C3 of C1 Ssphingosine, or at C3 of C18-sphinganine, or at the sialic acid acetyl group, and with C18-sphingosine and CIS-sphinganine, both labeled at C1. After a lipid pulse the cells were subjected until 7-day chase; measurements were then made of the radioactive products resulting from the administered long-chain base and ganglioside species catabolism and the salvage processes of catabolic fragments. From the data we drew the following conclusions.The G,, species differing in the long-chain base structure were taken up by the cells and metabolized. About 80% of the total catabolic CIS-sphingosine and C18-sphinganine were recycled for the biosynthesis of complex sphingolipids, the rest being degraded.Results obtained by administering ganglioside species of G,, containing radioactive sphingosine or the free radioactive sphingosine to fibroblasts suggested the existence in the cells of two quite separate pools of sphingosine. One pool was the direct result of either the catabolism of radioactive G,, highdensity microdomains or the diffusion of exogenous sphingosine into the cell; this pool was mainly used for the biosynthesis of the G,, species that contain palmitic and stearic acids. The other pool of sphingosine, the cell basal pool, came from the catabolism of radioactive sphingolipids in the recycling of sphingosine, and was used for the biosynthesis of the G,, species that mainly contain very long fatty acid chains, the main fibroblast endogenous species of GD3. Administration of the ganglioside species of G,, containing sphinganine or free sphinganine to fibroblasts yielded the G,, species containing mainly very long-chain fatty acids and sphingosine.These results show the possible existence of a pool of ganglioside-derived sphingosine, quite separate from the cell basal pool of sphingosine, suggesting that sphingosine derived from sphingolipid catabolism is reduced to sphinganine before entering the sphingolipid biosynthetic pathway.Keywords: ganglioside ; biosynthesis ; sphingosine ; sphinganine ; recycling.Gangliosides, sialic acid containing glycosphingolipids that are normal components of plasma membranes [I], are biosynthesized in the Golgi apparatus and degraded in the lysosomes [2] to fragments that are recycled for biosynthetic purposes [3-61. Among the ganglioside catabolic fragments, sphingosine has attracted scientific interest and increasing attention. It has been shown to act as an intracellular effector through the modulation of protein kinase C and other enzyme activities [7-91. Most of our present information arises from the administration of sphingosine to cells, but little is known about a potential role of a pool of sphingosine originated from ganglioside catabolism in modulating cell function.Catabolic sphingosine is partly recycled, but much of it is degraded [6, ; thus it is difficult to determine to what degree this recycling affects the overall sphingolipid turnover. Moreover, the de novo biosy...

show abstract

Section: [Sphh218-'h]g (Figs 4 and 5)mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Metabolic Processing of Gangliosides by Human Fibroblasts in Culture — Formation and Recycling of Separate Pools of Sphingosine

Chigorno

Riva

Valsecchi

et al. 1997

European Journal of Biochemistry

View full text Add to dashboard Cite

show abstract

“…Moreover, not all lipids follow the same processing path. Since Pagano's pioneering studies began, other researchers have used the same basic approach to study the sorting of lipids within differentiated or non-differentiated adenocarcinoma cells [34] or within polarized epithelial cells when the fluorescent lipids are introduced by spontaneous transfer to either the basolateral or apical cell surfaces [35][36][37].…”

Section: Ii-a Value As An Experimental Toolmentioning

confidence: 99%

Spontaneous lipid transfer between organized lipid assemblies

Brown

1992

Biochimica et Biophysica Acta (BBA) - Reviews on Biomembranes

View full text Add to dashboard Cite

“…This behavior appears to be shared by normal, as well as tumoral, proliferating, and differentiating cells [1]. It is believed that exogenous gangliosides are endocytosed and metabolically processed following the routes of intracellular traffic and metabolism of endogenous gangliosides [3,6,7].…”

Section: Introductionmentioning

confidence: 99%