Characterization of a low-activity allele of NADP+-dependent isocitrate dehydrogenase from Drosophila melanogaster |
| |
Authors: | Michael M Bentley Roy G Meidinger John H Williamson |
| |
Institution: | (1) Department of Biology, University of Calgary, T2N 1N4 Calgary, Alberta, Canada;(2) Department of Biology, Davidson College, 28036 Davidson, North Carolina |
| |
Abstract: | We have characterized biochemical effects of Idh
GB1
in Drosophila melanogaster. This is a null -activity allele for NADP+-dependent isocitrate dehydrogenase (NADP-IDH) isolated from a natural population. The homozygous mutant strain has 5% of the NADP-IDH specific activity found in controls and less than 24% of the immunologically cross-reacting material (CRM). This mutation maps to 27.2 on the third chromosome, to the right of h. The biochemical phenotype of this mutant strain includes a coordinate reduction in malic enzyme (ME) specific activity and CRM and an increase in specific activity for the pentose-phosphate shunt enzymes, 6-phosphogluconate dehydrogenase and glucose-6-phosphate dehydrogenase. The K
m
values for purified NADP-IDH are not different from those found for the purified control enzyme for NADP+ or isocitrate. It is suggested that this allele may represent a cis-acting control mutation for one of at least two loci involved in the production of NADP-IDH in D. melanogaster.Research supported by an Alberta Heritage Foundation for Medical Research Establishment Grant to MMB and a Natural Sciences and Engineering Research Council Operating Grant to JHW. |
| |
Keywords: | Drosophila melanogaster NADP+-dependent isocitrate dehydrogenase (NADP-IDH) cis-acting regulation population null alleles |
本文献已被 SpringerLink 等数据库收录! |