Changes in transglutaminase activity in carbon tetrachloride-damaged rat liver

Summary A significant decrease in transglutaminase (TGase) activity was observed in the cytosol and nuclear fractions of carbon tetrachloride-damaged rat liver. The degree of decrease in TGase activity in the cytosol fraction was closely related to the serum transaminase level. Gel filtration studies revealed that TGase activity in 80 kDa fractions significantly decreased, but that in 160 kDa fractions slightly increased after carbon tetrachloride treatment.     

Effect of retinoic acid on liver transglutaminase activity and carbon tetrachloride-induced liver damage in mice

Transglutaminase (TGase) activity in the cytosol fraction of the mouse liver increased following intraperitoneal injection of retinoic acid. Retinoic acid inhibited the carbon tetrachloride-induced increase in serum alanine transaminase activity. These findings suggest that TGase is involved in the effect of retinoic acid on carbon tetrachloride-induced liver damage.     

Effect of retinoic acid on liver transglutaminase activity and carbon tetrachloride-induced liver damage in mice.

Transglutaminase (TGase) activity in the cytosol fraction of the mouse liver increased following intraperitoneal injection of retinoic acid. Retinoic acid inhibited the carbon tetrachloride-induced increase in serum alanine transaminase activity. These findings suggest that TGase is involved in the effect of retinoic acid on carbon tetrachloride-induced liver damage.     

Distribution of CSF (colony stimulating factor) in kidney of the mouse

Summary The activity of the colony stimulating factor (CSF) was measured in kidney subcellular fractions in mice. The highest activity was noted in microsomes. From other fractions, the cytosol had large amounts of CSF. On the basis of literature data, and the findings presented we suggest that the kidney is at least one of the organs of CSF biosynthesis.     

Distribution of CSF (colony stimulating factor) in kidney of the mouse.

The activity of the colony stimulating factor (SCF) was measured in kidney subcellular fractions in mice. The highest activity was noted in microsomes. From other fractions, the cytosol had large amounts of CSF. On the basis of literature data, and the findings presented we suggest that the kidney is at least one of the organs of CSF biosynthesis.     

Inhibition of rat liver transglutaminase by nucleotides

Summary Tissue-type transglutaminase (TGase) was purified from rat liver, and the effects of nucleotides on its activity were examined. The enzyme activity is inhibited by ATP in a concentration-dependent way, with complete inhibition by 3 mM ATP. Partially-purified TGase from human brain was inhibited by ATP in a manner similar to that observed with the rat liver enzyme. This suggests that the inhibition is a common phenomenon for tissue-type TGase in all species and tissues. The inhibition is reversible since full activity is restored by lowering the ATP concentration. CTP has a TGase-inhibitory potency equivalent to that of ATP, whereas GTP and UTP possess about 50% of the inhibitory activity of ATP. ADP inhibits TGase activity to the same extent as ATP, but AMP causes much less inhibition, and there is no inhibition by adenosine or adenine. The inhibition by ATP is insensitive to ionic strength and is non-competitive with the substrate putrescine. Since ATP levels in cells are of mM order, these results suggest that TGase activity is controlled by ATP in vivo.     

Changes in the protein kinase C activity or rat sternomastoid muscle during development and after denervation

Summary The relationship between the activity of protein kinase C (PKC) and muscle innervation was explored in the rat sternomastoid muscle (SM) from day 18 of gestation (E18) to adult age. Between E18 and birth, PKC activity rose 5-fold, and during the day after birth, diminished to a level characteristic of the mature muscle. The rise chiefly occurred in the neural part of the muscle, in both the membrane and the cytosol fractions. Between E18 and day 5 after birth, the ratios of membrane to cytosol PKC activity rose from 0.5 to 10 and 3 respectively in the neural and aneural parts of the muscle. Denervation of adult SM reduced PKC activity by half in the membrane fraction of the neural part but did not significantly change it in the membrane or cytosol fractions of the aneural parts. These results suggest that innervation plays an important part in determining the level of PKC activity in muscle.     

Changes in the protein kinase C activity or rat sternomastoid muscle during development and after denervation

The relationship between the activity of protein kinase C (PKC) and muscle innervation was explored in the rat sternomastoid muscle (SM) from day 18 of gestation (E18) to adult age. Between E18 and birth, PKC activity rose 5-fold, and during the day after birth, diminished to a level characteristic of the mature muscle. The rise chiefly occurred in the neural part of the muscle, in both the membrane and the cytosol fractions. Between E18 and day 5 after birth, the ratios of membrane to cytosol PKC activity rose from 0.5 to 10 and 3 respectively in the neural and aneural parts of the muscle. Denervation of adult SM reduced PKC activity by half in the membrane fraction of the neural part but did not significantly change it in the membrane or cytosol fractions of the aneural parts. These results suggest that innervation plays an important part in determining the level of PKC activity in muscle.     

Inhibition of rat liver transglutaminase by nucleotides.

Tissue-type transglutaminase (TGase) was purified from rat liver, and the effects of nucleotides on its activity were examined. The enzyme activity is inhibited by ATP in a concentration-dependent way, with complete inhibition by 3 mM ATP. Partially-purified TGase from human brain was inhibited by ATP in a manner similar to that observed with the rat liver enzyme. This suggests that the inhibition is a common phenomenon for tissue-type TGase in all species and tissues. The inhibition is reversible since full activity is restored by lowering the ATP concentration. CTP has a TGase-inhibitory potency equivalent to that of ATP, whereas GTP and UTP possess about 50% of the inhibitory activity of ATP. ADP inhibits TGase activity to the same extent as ATP, but AMP causes much less inhibition, and there is no inhibition by adenosine or adenine. The inhibition by ATP is insensitive to ionic strength and is non-competitive with the substrate putrescine. Since ATP levels in cells are of mM order, these results suggest that TGase activity is controlled by ATP in vivo.     

Localization of pyruvate carboxylase in the cells of Neurospora crassa

The cell wall of Neurospora crassa was digested enzymatically and the cytosolic and the mitochondrial fractions were separated. The activity of pyruvate carboxylase (EC 6.4.1.1) was detected entirely in the cytosolic fraction. This indicates that the location of pyruvate carboxylase of N. crassa is in the cytosol, but is not in the mitochondria; this is different from the situation in animal tissues.     

Localization of pyruvate carboxylase in the cells ofNeurospora crassa

Summary The cell wall ofNeurospora crassa was digested enzymatically and the cytosolic and the mitochondrial fractions were separated. The activity of pyruvate carboxylase (EC 6.4.1.1) was detected entirely in the cytosolic fraction. This indicates that the location of pyruvate carboxylase ofN. crassa is in the cytosol, but is not in the mitochondria; this is different from the situation in animal tissues.     

A basic protein from bovine brain that co-precipitates with tubulin in vitro

A 193 kDa protein consisting of 58 kDa subunits, which has pI values of 8.50 and 8.65, was purified from bovine brain cytosol. It formed heavy precipitates with tubulin, and the molar ratio of tubulin dimer to this protein in the precipitate was 3.2. In contrast to microtubules containing ordinary microtubule-associated proteins, these complexes remained stable against cold and 1 mM CaCl2.     

Fucosidosis and blood group substances in the urine]

Glycopeptide and oligosaccharide fractions obtained from fucosidosis urine contains more Lea activity (4-8 fold) than control urine. Both fucosidosis fractions also contained Leb and H activities, no A activity in contrast to the salivary and erythrocyte phenotypes (A, Le a+ b-). The amount of Leb activity is lower in both fractions (1) and (2) than that of Leb control children (4-16 fold decrease). Blood group A activity was not detected at any concentration used (less than or equal to 50 fold-concentrated urine) whereas A activity was found in (A, Le a- b+) control urine. On the contrary, both fucosidosis fractions contained H activity, whereas A (Le a- b+) control children fractions had none (less than or equal to 50-fold concentrated urine). H and Leb activity might originate from Lea precursor apart from the "non-secretory" type of the patient.     

The involvement of fructose 2,6-bisphosphate in substrate cycle control in the nonoxidative stage of the pentose phosphate pathway. A phosphorus magnetic resonance spectroscopy study

The role of fructose 2,6-bisphosphate in the interconversion of sedoheptulose 7-phosphate and sedoheptulose 1,7-bisphosphate in rat liver cytosol fractions was studied by means of phosphorus magnetic resonance spectroscopy. When the activit of 6-phosphofructo-1-kinase was inhibited by a high concentration of ATP, the addition of fructose 2,6-bisphosphate led to a marked decrease in sedopheptulsoe 7-phosphate levels, accompanied by an increased concentration of ADP. Frructose 2,6-bisphosphate essentially inhibited both the decrease in sedoheptulose 1,7-disphosphate concentration and the accumulation of P_i in the incubation mixture. The data provided evidence that fructose 2,6-bisphosphate can regulate the substrate cycle; sedoheptulose 7-phosphate sedoheptulose 1,7-bisphosphate in the liver, and thus control the flux through the nonoxidative stage of the pentose phosphate pathway.     

A basic protein from bovine brain that co-precipitates with tubulin in vitro

A 193 kDa protein consisting of 58 kDa subunits, which has pI values of 8.50 and 8.65, was purified from bovine brain cytosol. It formed heavy precipitates with tubulin, and the molar ratio of tubulin dimer to this protein in the precipitate was 3.2. In contrast to microtubules containing ordinary microtubule-associated proteins, these complexes remained stable against cold and 1 mM CaCl₂.Acknowledgments. This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture of Japan.     

Calf thymus ribonuclease H IIa activity lacks ribonuclease H specificity.

Less purified fractions of ribonuclease H IIa activity of calf thymus display divalent cation-dependent ribonuclease H activity and divalent cation-independent ribonuclease activity. Because the ratio of the two enzyme activities does not change during successive chromatographic procedures, we suggest that ribonuclease H IIa activity is indeed able to degrade both ssRNA and the RNA moiety of RNA.DNA-hybrids. Ribonuclease H IIa activity can therefore be differentiated from calf thymus ribonuclease H I and H IIb by its lack of ribonuclease H specificity. The native molecular mass of ribonuclease H IIa activity is between 23 and 28 kDa. Under denaturing conditions a 23 kDa-protein band copurifies with the enzyme activity suggesting that this enzyme is monomeric.     

Calf thymus ribonuclease H IIa activity lacks ribonuclease H specificity

Summary Less purified fractions of ribonuclease H IIa activity of calf thymus display divalent cation-dependent ribonuclease H activity and divalent cation-independent ribonuclease activity. Because the ratio of the two enzyme activities does not change during successive chromatographic procedures, we suggest that ribonuclease H IIa activity is indeed able to degrade both ssRNA and the RNA moiety of RNA·DNA-hybrids. Ribonuclease H IIa activity can therefore be differentiated from calf thymus ribonuclease H I and H IIb by its lack of ribonuclease H specificity. The native molecular mass of ribonuclease H IIa activity is between 23 and 28 kDa. Under denaturing conditions a 23 kDa-protein band copurifies with the enzyme activity suggesting that this enzyme is monomeric.     

Evidence for enzymatic reduction of 1-nitropyrene by rat liver fractions

Summary 1-Nitropyrene, a mutagenic compound found in diesel exhaust and photocopy toners, is reduced anaerobically by rat liver fractions to 1-aminopyrene. This reaction is stimulated in the microsomal fraction by NADPH and in the cytosol by FMN. Addition of both cofactors produced more reduction in S-9, microsomes, or cytosol than either cofactor alone.     

Identification and possible biological relevance of spermatozoal transglutaminase.

Normal human spermatozoa were demonstrated by dot immunoblot analysis and immunohistochemistry to possess transglutaminase (TGase). The immunological identification of spermatozoal TGase is consistent with reports by others of its biochemical identification and suggested role in sperm motility, and provides, in view of the immunoregulatory properties of seminal plasma TGase, presumptive identification of a means whereby spermatozoa, under normal physiological conditions, may possibly be protected from immunological 'attack' within the female reproductive tract.     

Translocation of hepatic cytosol androgen receptor to the nucleus in vivo in male rats

Summary Testosterone, which was injected s.c. into adult male rats castrated 15 h prior to the injection, decreased the number of androgen-specific binding sites in the cytosol at 30 min. Coincidentally, a substantial increase was observed in the nucleus. The decreased number of the sites in the cytosol was restored to the initial level at 60 min; on the contrary, a decrease was observed in the nucleus.