Hexose-6-phosphate dehydrogenase in the endoplasmic reticulum.
Hexose-6-phosphate dehydrogenase (H6PD) is a luminal enzyme of the endoplasmic reticulum that is distinguished from cytosolic glucose-6-phosphate dehydrogenase by several features. H6PD converts glucose-6-phosphate and NADP(+) to 6-phosphogluconate and NADPH, thereby catalyzing the first two reactions of the pentose-phosphate pathway. Because the endoplasmic reticulum has a separate pyridine nucleotide pool, H6PD provides NADPH for luminal reductases. One of these enzymes, 11beta-hydroxysteroid dehydrogenase type 1 responsible for prereceptorial activation of glucocorticoids, has been the focus of much attention as a probable factor in the pathomechanism of several human diseases including insulin resistance and the metabolic syndrome. This review summarizes recent advances related to the functions of H6PD.
Senesi
Silvia
S
Department of Pathophysiology, Experimental Medicine and Public Health, University of Siena, I-53100 Siena, Italy.
Csala
Miklos
M
Marcolongo
Paola
P
Fulceri
Rosella
R
Mandl
Jozsef
J
Banhegyi
Gabor
G
Benedetti
Angelo
A
D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1 / Q000235:genetics / Q000378:metabolism; D000818:Animals; D003349:Cortisone Reductase / Q000172:deficiency; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D005954:Glucosephosphate Dehydrogenase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D009249:NADP / Q000378:metabolism*; D010427:Pentose Phosphate Pathway
D009249:NADP; D043205:11-beta-Hydroxysteroid Dehydrogenase Type 1; D005954:Glucosephosphate Dehydrogenase; D003349:Cortisone Reductase