Genetic and biochemical studies of the hexose monophosphate shunt in Neurospora crassa. II. Characterization of biochemical defects of the morphological mutants colonial 2 and colonial 3

1971 ◽  
Vol 17 (6) ◽  
pp. 789-794 ◽  
Author(s):  
John F. Lechner ◽  
Kathyrn E. Fuscaldo ◽  
George Bazinet
Keyword(s):  
Neurospora Crassa ◽  
State Level ◽  
Hexose Monophosphate ◽  
Wild Type Enzyme ◽  
Hexose Monophosphate Shunt ◽  
Acid Dehydrogenase ◽  
Morphological Mutants ◽  
Altered Form ◽  
Glucose 6 Phosphate Dehydrogenase

The two dehydrogenases of the hexose monophosphate shunt, glucose-6-phosphate dehydrogenase and 6-phosphogluconic acid dehydrogenase, were examined in two morphology mutants of Neurospora crassa. Glucose-6-phosphate dehydrogenase extracted from the mutant colonial-2 was found in an altered form as compared to the wild-type enzyme. The second enzyme of the pathway was observed to be abnormal in the mutant colonial-3. In addition, 6-phosphogluconic acid dehydrogenase was found to exhibit non-classical kinetics. The data indicate that the altered morphology exhibited by both colonial-2 and colonial-3 is due to the suboptimal capacity of the hexose monophosphate shunt to function normally. This physiological impairment of the pathway is reflected in a lowered cellular steady-state level of NADP.

scholarly journals Glucose-6-phosphate-dehydrogenase-deficient erythrocytes have an impaired shape recovery mechanism

Blood ◽  
1984 ◽  
Vol 63 (5) ◽  
pp. 1198-1202
Author(s):  
E Alhanaty ◽  
M Snyder ◽  
MP Sheetz
Keyword(s):  
Cell Shape ◽  
Shape Recovery ◽  
Cell Function ◽  
Hexose Monophosphate ◽  
Recovery Rates ◽  
Chloromethyl Ketone ◽  
Hexose Monophosphate Shunt ◽  
Recovery Mechanism ◽  
Normal Shape ◽  
Glucose 6 Phosphate Dehydrogenase

In the human erythrocyte, the maintenance of the biconcave disc shape is important for cell viability as well as cell function. Previous studies have indicated the involvement of the hexose monophosphate shunt in the recovery of discoid shape after perturbation of echinocytic agents. In glucose-6-phosphate-dehydrogenase-deficient (Gd- ) erythrocytes, the shunt activity is significantly decreased; thus, it might be expected that the shape recovery rate of Gd- erythrocytes would be decreased. We show here that shape recovery rates in the presence of the shunt stimulator methylene blue are as much as fivefold lower in Gd- erythrocytes. We also show that the protease inhibitor, N- alpha-tosyl-1-phenylalanine-chloromethyl ketone, has no effect on shape recovery in Gd-, whereas it increases normal cell shape recovery rates by 10–30-fold at 50 microM and causes cupping at 200 microM (see companion article by Alhanaty et al.). These changes are not due to reticulocytosis, as other hemolytic disorders do not show such changes. Further, both chronic hemolyzing Gd and A Gd variants show similar abnormal shape recovery behavior, whereas the extent of hemolysis is quite different between variants. Thus, the activity of the hexose monophosphate shunt appears to have a dramatic effect on the rate of reversal of echinocytosis. The lack of shunt activity of Gd cells would necessarily impair their ability to recover normal shape after perturbation.

scholarly journals Molecular characterization of four morphological mutants of Neurospora crassa

2014 ◽  
Vol 23 (1) ◽  
pp. 85-91
Author(s):  
Nasrin Akter ◽  
Ahashan Habib ◽  
Salina Parvin Beauty ◽  
Tahsina Rahim ◽  
Mohammad Nurul Islam
Keyword(s):  
Neurospora Crassa ◽  
Uv Light ◽  
Carotenoid Biosynthesis ◽  
Biosynthesis Pathway ◽  
Molecular Features ◽  
Albino Mutant ◽  
Morphological Mutants ◽  
Banding Profile ◽  
Carotenoid Biosynthesis Pathway

Four morphological mutants (albino, ropy, conidial band and buff) of Neurospora crassa were characterized based on morphological features and molecular markers. The mycelial color of mutants buff, ropy and conidial band were more or less orange like wild parents. Albino mutant showed colorless mycelium. The germination time of conidia of wild and other mutants ranged from 5 to 7 days while in albino it was 12 days. Esterase and acid phosphatase isozymes analysis of the N. crassa mutants clearly indicated that mutation altered the carotenoid biosynthesis pathway creating the albino mutant due to the effect UV light. Most of the mutants viz; albino, conidial band and buff showed characteristic RAPD banding profile. However, no band was found in wild EmA, Ema and mutant ropy. Highest number of RAPD bands were found in albino. The mutant albino showed very different morphological and molecular features from the rest specimens. DOI: http://dx.doi.org/10.3329/dujbs.v23i1.19831 Dhaka Univ. J. Biol. Sci. 23(1): 85-91, 2014

Hexose Monophosphate Shunt Enzymes in Lung Tumors from Normal and Glucose-6-Phosphate-Dehydrogenase-Deficient Subjects

Oncology ◽  
1988 ◽  
Vol 45 (4) ◽  
pp. 287-291 ◽  
Author(s):  
S. Dessì ◽  
B. Batetta ◽  
R. Cherchi ◽  
R. Onnis ◽  
M. Pisano ◽  
...  
Keyword(s):  
Lung Tumors ◽  
Hexose Monophosphate ◽  
Hexose Monophosphate Shunt ◽  
Glucose 6 Phosphate Dehydrogenase

scholarly journals Glucose-6-phosphate-dehydrogenase-deficient erythrocytes have an impaired shape recovery mechanism

Blood ◽  
1984 ◽  
Vol 63 (5) ◽  
pp. 1198-1202 ◽  
Author(s):  
E Alhanaty ◽  
M Snyder ◽  
MP Sheetz
Keyword(s):  
Cell Shape ◽  
Shape Recovery ◽  
Cell Function ◽  
Hexose Monophosphate ◽  
Recovery Rates ◽  
Chloromethyl Ketone ◽  
Hexose Monophosphate Shunt ◽  
Recovery Mechanism ◽  
Normal Shape ◽  
Glucose 6 Phosphate Dehydrogenase

Abstract In the human erythrocyte, the maintenance of the biconcave disc shape is important for cell viability as well as cell function. Previous studies have indicated the involvement of the hexose monophosphate shunt in the recovery of discoid shape after perturbation of echinocytic agents. In glucose-6-phosphate-dehydrogenase-deficient (Gd- ) erythrocytes, the shunt activity is significantly decreased; thus, it might be expected that the shape recovery rate of Gd- erythrocytes would be decreased. We show here that shape recovery rates in the presence of the shunt stimulator methylene blue are as much as fivefold lower in Gd- erythrocytes. We also show that the protease inhibitor, N- alpha-tosyl-1-phenylalanine-chloromethyl ketone, has no effect on shape recovery in Gd-, whereas it increases normal cell shape recovery rates by 10–30-fold at 50 microM and causes cupping at 200 microM (see companion article by Alhanaty et al.). These changes are not due to reticulocytosis, as other hemolytic disorders do not show such changes. Further, both chronic hemolyzing Gd and A Gd variants show similar abnormal shape recovery behavior, whereas the extent of hemolysis is quite different between variants. Thus, the activity of the hexose monophosphate shunt appears to have a dramatic effect on the rate of reversal of echinocytosis. The lack of shunt activity of Gd cells would necessarily impair their ability to recover normal shape after perturbation.

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