The identification of specific genetic loci that contribute to inflammatory and autoimmune diseases has proved difficult due to the contribution of multiple interacting genes, the inherent genetic heterogeneity present in human populations, and a lack of new mouse mutants. By using N-ethyl-N-nitrosourea (ENU) mutagenesis to discover new immune regulators, we identified a point mutation in the murine phospholipase Cg2 (Plcg2) gene that leads to severe spontaneous inflammation and autoimmunity. The disease is composed of an autoimmune component mediated by autoantibody immune complexes and B and T cell independent inflammation. The underlying mechanism is a gain-of-function mutation in Plcg2, which leads to hyperreactive external calcium entry in B cells and expansion of innate inflammatory cells. This mutant identifies Plcg2 as a key regulator in an autoimmune and inflammatory disease mediated by B cells and non-B, non-T haematopoietic cells and emphasizes that by distinct genetic modulation, a single point mutation can lead to a complex immunological phenotype.

glk, the structural gene for glucokinase of Escherichia coli, was cloned and sequenced. Overexpression of glk resulted in the synthesis of a cytoplasmic protein with a molecular weight of 35,000. The enzyme was purified, and its kinetic parameters were determined. Its K m values for glucose and ATP were 0.78 and 3.76 mM, respectively. Its V max was 158 U/mg of protein. A chromosomal glk-lacZ fusion was constructed and used to monitor glk expression. Under all conditions tested, only growth on glucose reduced the expression of glk by about 50%. A fruR mutation slightly increased the expression of glk-lacZ, whereas the overexpression of plasmid-encoded fruR ؉ weakly decreased expression. A FruR consensus binding motif was found 123 bp upstream of the potential transcriptional start site of glk. Overexpression of glk interfered with the expression of the maltose system. Repression was strongest in strains that exhibited constitutive mal gene expression due to endogenous induction and, in the absence of a functional MalK protein, the ATP-hydrolyzing subunit of the maltose transport system. It was least effective in wild-type strains growing on maltose or in strains constitutive for the maltose system due to a mutation in malT rendering the mal gene expression independent of inducer. This demonstrates that free internal glucose plays an essential role in the formation of the endogenous inducer of the maltose system.In Escherichia coli and most other bacteria, glucose is transported by the phosphoenolpyruvate:sugar phosphotransferase system (PTS) as glucose-6-phosphate (53), thus eliminating the need for glucokinase in the utilization of glucose. In contrast, the utilization of glucose-containing disaccharides such as lactose, maltose, or trehalose involves the formation of glucose inside the cell and requires its phosphorylation for the effective utilization of the disaccharides. Surprisingly, the presence of a glk mutation (22) does not appear to be a disadvantage in the utilization of these disaccharides. Severe reduction in growth is observed only when, in addition to having the glk mutation, the strain also lacks the ability to phosphorylate glucose via the PTS pathway (14, 59). Two different findings might be relevant for this phenomenon. In the first, glucose and galactose, the products of intracellular ␤-galactosidase action, have been found in large amounts outside the cell after the uptake of lactose, implying that growth on lactose is mediated via the uptake of the secreted products (PTS-mediated phosphorylation in the case of glucose) (35). In the second, internal phosphorylation of glucose by the PTS has been evoked (14). The findings indicate that the enzyme II Glc is also responsible for the utilization of internal glucose.As a consequence, the interest in E. coli glucokinase has been low. Glucokinase activity in E. coli was measured as early as 1953 (21), and MM6, an E. coli mutant defective in the utilization of glucose, was shown to contain normal amounts of glucokinase (4). In that study, the K m of...

ATX for 9 weeks significantly reduced symptoms of ODD/CD and ADHD; slower ATX-up-titration may be better tolerated.

This study suggests positive effects of atomoxetine on quality of life, as measured by the KINDL-R scores on emotional well-being, self-esteem, friends and family, in children and adolescents with ADHD and comorbid ODD/CD. No significant treatment effects were seen on family burden, as measured by FaBel total score.

malZ is a member of the mal regulon. It is controlled by MalT, the transcriptional activator of the maltose system. MalZ has been purified and identified as an enzyme hydrolyzing maltotriose and longer maltodextrins to glucose and maltose. MalZ is dispensable for growth on maltose or maltodextrins. Mutants lacking amylomaltase (encoded by malQ), the major maltose utilizing enzyme, cannot grow on maltose, maltotriose, or maltotetraose, despite the fact that they contain an effective transport system and MalZ. From such a malQ mutant a pseudorevertant was isolated that was able to grow on maltose. The suppressor mutation was mapped in malZ. The mutant gene was cloned. It contained a Trp to Cys exchange at position 292 of the deduced protein sequence. Surprisingly, the purified mutant enzyme was still unable to hydrolyze maltose as was the wild type enzyme, while both were able to release glucose from maltodextrins. However, the mutant enzyme had gained the ability to transfer dextrinyl moieties to glucose, maltose, and other maltodextrins. Thus, it had gained an activity associated with amylomaltase. It was the MalZ292-associated transferase reaction that allowed the utilization of maltose. In addition, we discovered that mutant and wild type enzymes alike were highly active as ␥-cyclodextrinases.The Escherichia coli maltose system (1, 2) contains two enzymes that are necessary for the utilization of maltose and maltodextrins. Maltotriose, after having been taken up by the high affinity and binding protein-dependent ABC (ATP binding cassette) transport system (3) is recognized by amylomaltase (encoded by malQ) (4), the reducing end glucose is released and the maltosyl residue is transferred to another maltotriose molecule thus forming maltopentaose (5, 6). The repetition of this cycle leads to the formation of long maltodextrins and free glucose which, after phosphorylation by glucokinase enters glycolysis. Maltopentaose and longer maltodextrins are recognized by maltodextrin phosphorylase (encoded by malP) (7,8) which, by phosphorolysis, releases the nonreducing end glucose as glucose 1-phosphate. Thus, the final products of maltodextrin metabolism by these two enzymes are glucose and glucose 1-phosphate.The degradation of maltose, the smallest member of maltodextrins, also requires amylomaltase, and malQ mutants are MalϪ . However, amylomaltase does not recognize maltose as glucosyl donor, only as maltodextrinyl acceptor (6). Therefore, in order to metabolize maltose, amylomaltase requires a maltodextrin primer with the minimal size of maltotriose. Within the cell, the required maltodextrin primer can originate from the degradation of glycogen or from the action of an as yet uncharacterized maltose/maltotriose phosphorylase with glucose and glucose 1-phosphate as starting material (9).There are two more enzymes, members of the mal regulon, that are not essential for the metabolism of maltose and small maltodextrins. One is a periplasmic ␣-amylase encoded by malS (10, 11). This enzyme hydrolyzes larger dextrins i...