The concentration of fructose 2,6-bisphosphate in the brain remained stable during starvation and early stages of ischaemia, but decreased in diabetes or after lengthened ischaemia. 6-Phosphofructo-1-kinase activity was also decreased in diabetic and ischaemic animals, whereas 6-phosphofructo-2-kinase was not modified. The concentration of the bisphosphorylated metabolite seems to be remarkably constant under a wide variety of experimental conditions, suggesting that it plays an essential role in the basal activation of 6-phosphofructo-1-kinase. Purified 6-phosphofructo-2-kinase also showed fructose-2,6-bisphosphatase activity with an activity ratio similar to that of the purified heart isoenzyme. The brain enzyme also has a net charge similar to that of the heart isoenzyme. Its activity is not modified by sn-glycerol 3-phosphate, and it is more sensitive to citrate than the liver or muscle isoenzyme. Moreover, the enzyme from brain, similarly to that from heart and muscle, is not modified by the cyclic AMP-dependent protein kinase or protein kinase C. A near-full-length cDNA probe from liver hybridized with RNA from brain and heart. In both cases, a major band of 6.8 kb of RNA and a minor one of 4 kb of RNA were detected. All these properties support the hypothesis that brain contains a different isoenzymic form from that of liver and muscle, and it is probably related to the heart isoform.
Skip Nav Destination
Article navigation
June 1991
-
Cover Image
Cover Image
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
- PDF Icon PDF LinkAdvertising
Research Article|
June 01 1991
6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase in rat brain
F Ventura;
F Ventura
1Unitat de Bioquimica, Departament de Ciències Fisiològiques, Zona Universitària Bellvitge, Universitat de Barcelona, 08907 L'Hospitalet, Spain.
Search for other works by this author on:
J L Rosa;
J L Rosa
1Unitat de Bioquimica, Departament de Ciències Fisiològiques, Zona Universitària Bellvitge, Universitat de Barcelona, 08907 L'Hospitalet, Spain.
Search for other works by this author on:
S Ambrosio;
S Ambrosio
1Unitat de Bioquimica, Departament de Ciències Fisiològiques, Zona Universitària Bellvitge, Universitat de Barcelona, 08907 L'Hospitalet, Spain.
Search for other works by this author on:
J Gil;
J Gil
1Unitat de Bioquimica, Departament de Ciències Fisiològiques, Zona Universitària Bellvitge, Universitat de Barcelona, 08907 L'Hospitalet, Spain.
Search for other works by this author on:
R Bartrons
R Bartrons
1Unitat de Bioquimica, Departament de Ciències Fisiològiques, Zona Universitària Bellvitge, Universitat de Barcelona, 08907 L'Hospitalet, Spain.
Search for other works by this author on:
Publisher: Portland Press Ltd
Online ISSN: 1470-8728
Print ISSN: 0264-6021
© 1991 The Biochemical Society, London
1991
Biochem J (1991) 276 (2): 455–460.
Citation
F Ventura, J L Rosa, S Ambrosio, J Gil, R Bartrons; 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase in rat brain. Biochem J 1 June 1991; 276 (2): 455–460. doi: https://doi.org/10.1042/bj2760455
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.