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Distribution of the Glucose‐1,6‐Bisphosphate System in Brain and Retina
Author(s) -
Yip Vera,
Pusateri Mary Ellen,
Carter Joyce,
Rose Irwin A.,
Lowry Oliver H.
Publication year - 1988
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1988.tb02952.x
Subject(s) - phosphoglucomutase , biology , cerebrum , cerebellum , phosphoglycerate mutase , phosphatase , biochemistry , endocrinology , central nervous system , medicine , enzyme , neuroscience , chemistry , glycolysis
The distribution of glucose‐1,6‐bisphosphate (G16P 2 ) synthase was measured in more than 70 regions of mouse brain, and nine layers of monkey retina. Activities in gray areas varied as much as 10‐fold, in a hierarchical manner, from highest in telencephalon. especially the limbic system, to lowest in cerebellum, medulla, and spinal cord. The synthase levels were significantly correlated among different regions with G16P 2 itself, as well as with previously published levels of a brain specific IMP‐dependent G16P 2 phosphatase. In contrast, neither G16P 2 nor either its synthase or phosphatase correlated positively with phosphoglucomutase. and in all regions the G16P 2 levels greatly exceeded requirements for activation of this mutase. This strengthens the view that G16P : has some function besides serving as coenzyme for phosphoglucomutase. However, attempts to correlate the “G16P 2 system,” as defined by the three coordinately related elements, synthase, phosphatase, and G16P 2 , with other enzymes of carbohydrate metabolism, or with regional data of Sokoloff et al. [ J. Neurochem . 28, 897–916 (1977)] for glucose consumption, were unsuccessful. This leaves open the possibility that brain G16P 2 might serve as a phosphate donor for specific nonmetabolic effector proteins.