Sedoheptulose diphosphate formation by the human red blood cell

Bucolo, Giovanni; Bartlett, Grant R.

doi:10.1016/0006-291x(60)90073-5

Cited by 15 publications

(1 citation statement)

References 11 publications

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“…The resulting SBP is then cleaved by aldolase to generate E4P and DHAP (Nakahigashi et al, 2009). Sedoheptulose and octulose compounds have also been observed in human tissues (Bartlett and Bucolo, 1960; Bucolo and Bartlett, 1960). In macrophages stimulated by endotoxin, a sedoheptulose kinase that produces S7P from sedoheptulose must be downregulated for proper activation (A. Haschemi, personal communication).…”

Section: Discussionmentioning

confidence: 99%

Riboneogenesis in Yeast

Clasquin

Melamud

Singer

et al. 2011

Cell

111

129

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Summary Gluconeogenesis converts three carbon units into glucose. Here we identify an analogous pathway in Saccharomyces cerevisiae for converting three carbon units into ribose, a component of nucleic acids and nucleotides. This riboneogenic pathway involves the enzyme sedoheptulose-1,7-bisphosphatase (SHB17), whose activity was identified based on accumulation of sedoheptulose-1,7-bisphosphate in the corresponding knockout strain. We determined the crystal structure of Shb17 in complex with sedoheptulose-1,7-bisphosphate, and found that the sugar is bound in the closed furan form in the active site. Like fructose-1,6-bisphosphate, sedoheptulose-1,7-bisphosphate is produced by aldolase, in this case from erythrose 4-phosphate and dihydroxyacetone phosphate. Hydrolysis of sedoheptulose-1,7-bisphosphate by SHB17 provides an energetically favorable input to the non-oxidative pentose phosphate pathway to drive ribose production. Flux through SHB17 is enhanced under conditions when ribose demand is high relative to demand for NADPH, including during ribosome biogenesis in metabolically synchronized yeast cells. Thus, riboneogenesis provides a thermodynamically-driven route of ribose production uncoupled from formation of NADPH.

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Section: Discussionmentioning

confidence: 99%