PstB protein of the phosphate-specific transport system of Escherichia coli is an ATPase.

The PstB protein of the phosphate-specific transport (Pst) system of Escherichia coli bound and hydrolyzed ATP, producing ADP. Urea-treated denatured PstB did not bind ATP. The N-terminal amino acid sequence of the immune serum-precipitable PstB protein was determined, and it corresponded to that deduced from the DNA sequence.

Effect of glpT and glpD mutations on expression of the phoA gene in Escherichia coli.

In vivo 31P nuclear magnetic resonance analysis of Escherichia coli cells showed that the intracellular concentration of P(i) remained constant in wild-type and in a glpT mutant strain whether the cells were grown on excess (2 mM) P(i) or sn-glycerol-3-phosphate as a phosphate source. The function of the phoA promoter (measured by beta-galactosidase activity in a phoA-lacZ fusion strain) was repressed when glpT+ cells were utilizing sn-glycerol-3-phosphate as the sole source of phosphate. These cells were devoid of alkaline phosphatase activity.

Role of PhoU in phosphate transport and alkaline phosphatase regulation.

The negative regulatory function of PhoU in alkaline phosphatase (AP) was suggested by the behavior of K10 phoU35 carrying a missense mutation whose product was detected by immunoblotting. To define more clearly the regulatory function of this protein for the synthesis of AP, we constructed a null mutation. The constitutive synthesis of AP in this phoU deletion strain confirmed the negative role of PhoU.

From cell membrane to nucleotides: the phosphate regulon in Escherichia coli.

Most of the essential cellular components, like nucleic acids, lipids and sugars, are phosphorylated. The phosphate equilibrium in Escherichia coli is regulated by the phosphate (Pi) input from the surrounding medium. Some 90 proteins are synthesized at an increased rate during Pi starvation and the global control of the cellular metabolism requires cross-talk with other regulatory mechanisms.

Molecular aspects of phosphate transport in Escherichia coli.

Escherichia coli transports inorganic phosphate (Pi) by the low-affinity transport system, Pit. When the level of the external Pi is lower than 20 microM, another transport system, Pst, is induced with a Kt of 0.25 microM.

Utilization by Escherichia coli of a high-molecular-weight, linear polyphosphate: roles of phosphatases and pore proteins.

We observed that wild-type Escherichia coli utilized a linear polyphosphate with a chain length of 100 phosphate residues (poly-P100) as the sole source of phosphate in growth medium. A mutation in the gene phoA of alkaline phosphatase or phoB, the positive regulatory gene, prevented growth in this medium. Since no alkaline phosphatase activity was detected outside the wild-type cells, the periplasmic presence of the enzyme was necessary for the degradation of polyphosphate.

The influence of thyroid hormones on colony growth of peripheral CFU-GM from normal and leukemic subjects.

In order to clarify the alterations of granuloblastic cells in chronic and acute myeloid leukemia, the colony growth behavior of cultured CFU-GM from the peripheral blood of normal and leukemic subjects was examined in basal conditions and after adding to the medium T3 or T4 and/or thioproline and/or flurbiprofen. These drugs had in previous investigations proved their ability to modify cellular receptors and the uptake of thyroid hormones. The study was carried out in semisolid (double agar layer) and liquid medium, utilizing the techniques described previously.

[Penbutolol and arterial hypertension].

Penbutolol has proved particularly effective and suitable for the treatment, even on a long-term basis, of recently developed hypertension, especially in its hyperkinetic forms. The drug produces minimal side effects, is well tolerated and gives an early therapeutic response. In addition penbutolol does not cause any significant alterations in the biohumoral parameters of the patients treated and is ideal for combination with dihydralazine, reserpine and dihydrochlorotiazide in the treatment of more stubborn cases, making it possible to reduce the doses of the other drugs without causing bradycardia.

Nucleotide pool in pho regulon mutants and alkaline phosphatase synthesis in Escherichia coli.

The intracellular nucleotide pool of Escherichia coli W3110 reproducibly changes from conditions of growth in phosphate excess to phosphate starvation, with at least two nucleotides appearing under starvation conditions and two nucleotides appearing only under excess phosphate conditions. Strains bearing a deletion of the phoA gene show the same pattern, indicating that dephosphorylation by alkaline phosphatase is not responsible for the changes. Strains with mutations in the phoU gene, which result in constitutive expression of the pho regulon, show the nucleotide pattern of phosphate-starved cells even during phosphate excess growth.

[The role of plasmapheresis in the treatment of primary and secondary cryoglobulinemia].

The data on monoclonal or mixed cryoglobulinaemia patients admitted to Pavia University's 1st Medical Division since 1970 were examined. Complications included peripheral microangiopathies caused by immune complexes and especially kidney lesions of varying severity caused by immune complexes precipitated in the basal membrane. Although the course of the condition was ameliorated in all patients given immunosuppressive treatment alone, this could not prevent the appearance of progressively worsening kidney conditions.

Amount and chain length of polyphosphates in Escherichia coli depend on cell growth conditions.

Anaerobiosis induced an accumulation of polyphosphates (poly Pi) in a phosphate-rich medium by an alkaline-phosphatase constitutive mutant of Escherichia coli. The total poly Pi content was maximum at around 6 h of anaerobic growth. Both trichloroacetic acid- and NaOH-soluble poly Pi were found to be present.

Identification of the phoM gene product and its regulation in Escherichia coli K-12.

Plasmids containing the chromosome region of Escherichia coli encoding phoM, whose product is a positive regulator of alkaline phosphatase expression, were isolated from the Clarke and Carbon plasmid bank. A 9.9-kilobase EcoRI fragment of plasmid pLC17-39 (subcloned into pBR322) was able to complement both phoM and thrB mutations.

Drugs affecting the hormonal receptors of normal and leukaemic peripheral leucocytes.

The authors investigated the behaviour of steroid hormone uptake in leukaemic cells (CML, CLL, AML, ALL), in basal conditions and after incubation with drugs which modify the cellular concentration of cAMP, PGE and PGF. The results demonstrated the presence in leukaemic cells of an alteration in the incorporation of steroid hormones. This alteration was scarcely modified by incubation with theophylline, which increases cellular concentration of cAMP.

[Plasmapheresis and survival of patients with myeloma and secondary renal insufficiency].

The mortality rate due to renal insufficiency in patients with myelomas was studied and the results obtained compared with figures on patients given plasmapheresis to correct the insufficiency. The results of the comparison confirm the value of the immediate use of plasmapheresis on patients with myelomas. In a large percentage of cases, the technique either completely cured or significantly improved renal dysfunction, thus normalizing the blood and urine situation and improving the patients' chances of survival.

[Behavior of the principal protein hormones in normal and leukemic leukocytes].

GH, LH, insulin and glucagon patterns were studied in the peripheral leukocytes of normal subjects (granulocytes and lymphocytes separated on a Ficoll-Hypaque gradient) and leukaemic patients (CML, AML, CLL, and ALL), using a double antibody RIA on whole cells. The uptake of 125I-labelled insulin and GH by these cells was also assessed. The results showed that in leukaemia, particularly CLL, ALL and AML, though not in CML, there was a constant reduction in hormone values, plus depressed GH and insulin uptake.

Seminalplasmin inhibits transcription and translation of phi80 DNA in vitro.

Seminalplasmin, an antimicrobial protein from bovine seminal plasma that has been earlier shown to inhibit transcription in whole cells and by purified RNA polymerase in vitro, but not translation in whole cells, is now shown to inhibit both transcription and translation independently of each other, in a coupled transcription-translation system from E. coli using phi80dphoAlacZ DNA as the template.

Genetic and physiological tests of three phosphate-specific transport mutants of Escherichia coli.

Phosphate-specific transport system mutations phoT35, pst-2, and phoS25-(Am) were mapped between bgl and glmS, at about 83 min on the Escherichia coli chromosome. All three mutations were recessive to wild-type genes on transducing bacteriophage lambda asn. The phoS25 (Am) and pst-2 mutations were also recessive to transducing phage lambda dglm; however, the phoT35 mutation was not.

Pleiotropic effects of alkaline phosphatase regulatory mutations phoB and phoT on anaerobic growth of and polyphosphate synthesis in Escherichia coli.

The appearance during anaerobiosis of spontaneous phoT phoB double mutants in a phoT background is described. During both exponential growth and stationary phase, selection against the phoT mutants relative to the wild type was evident. This reduction in viability of phoT mutants was suppressed in phoT phoB double mutants.

Complementation test between alkaline phosphatase regulatory mutations phoB and phoRc in Escherichia coli.

A phoRc and a phoB mutation belong to the same complementation group suggesting that there is a single positive control gene for alkaline phosphatase synthesis.

Genetic analysis of regulatory mutants of alkaline phosphatase of E. coli.

A fine structure map of the phoR region of E. coli, mutations of which affect the rate of alkaline phosphatase synthesis, was constructed by Hfr X F- crosses. Mutations causing three different phenotypes (previously reported as phoRa, phoRb, phoRc (Garen and Echols 1962a,b) are clustered in three closely linked genetic loci.

Protease associated with spores of Bacillus cereus.

A proteolytic activity is associated with the dormant spores of Bacillus cereus T and can be solubilized by washing the spores with 1 M KCl. This proteolytic activity is responsible for the attack of beta chains of ribonucleic acid-polymerase in extracts of dormant spores of this organism.