Fructose-2, 6-bisphosphate (fru-2, 6P2), synthesized by 6-phosphofructo-2-kinase (PFK2), regulates glucose metabolism via modulating phosphofructokinase-1 (PFK1) and fructose-1, 6-bisphosphatase (FBPase1) reciprocally in mammalian tissues. How this control system develops in brain is poorly understood. This article presents the postnatal comparative profiles of fru-2, 6P2 and PFK2 & fru-2, 6P2 dependent regulation of PFK1 and FBPase1 in mice brain. Fru-2, 6P2 and PFK2 activity both attained their adult levels in concordance from day1 to 1wk age. Western blot analysis of mice liver and brain & rat liver PFK2 using anti rat liver PFK2/FBPase2 confirmed that both, mice liver and brain isoforms cross- react efficiently with this antibody. In addition, DEAE-eluted brain fractions from different postnatal ages revealed that 1day mice brain expresses a liver type enzyme (∼55 kDa) that is replaced by an adult brain type protein (∼110 kDa) from 1wk onward ages. As compared to 1day mice, significantly decreased Km values of PFK2 at 1wk-10wk ages also suggest the existence of a kinetically different isoform of this enzyme from 1wk onward ages. In vitro effects of fru-2, 6P2 on partially enriched brain PFK1 and FBPase1 suggest that fru-2, 6P2 dependent respective stimulatory and inhibitory responses of both these enzymes increase progressively from day1 to 3wk age. This is well corroborated with the postnatal age-dependent linear increase in PFK1 and decrease in FBPase1 activities in mice brain. The results suggest that fru-2, 6P2 associated regulatory components develop in concordance in mice brain during early postnatal life.
| Identifer | oai:union.ndltd.org:ETSU/oai:dc.etsu.edu:etsu-works-19591 |
| Date | 07 December 2005 |
| Creators | Pandey, Pankaj, Singh, Sanjay K., Trigun, Surendra K. |
| Publisher | Digital Commons @ East Tennessee State University |
| Source Sets | East Tennessee State University |
| Detected Language | English |
| Type | text |
| Source | ETSU Faculty Works |
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