Inorganic polyphosphate in Escherichia coli: the phosphate regulon and the stringent response.

Escherichia coli transiently accumulates large amounts of inorganic polyphosphate (polyP), up to 20 mM in phosphate residues (Pi), in media deficient in both Pi and amino acids. This transient accumulation is preceded by the appearance of nucleotides ppGpp and pppGpp, generated in response to nutritional stresses. Mutants which lack PhoB, the response regulator of the phosphate regulon, do not accumulate polyP even though they develop wild-type levels of (p)ppGpp when subjected to amino acid starvation.

Paroxysmal tonic upgaze: a reappraisal of outcome.

Paroxysmal tonic upgaze (PTU) of childhood is a distinctive neuro-ophthalmological syndrome of unknown etiology and pathogenesis that is characterized by episodes of sustained upward deviation of the eyes, often with incomplete downward saccades on attempted downgaze. It is generally regarded as having a benign outcome. We observed 16 children with PTU, from 10 months to 11 years from onset (mean, 5.

Novel assay reveals multiple pathways regulating stress-induced accumulations of inorganic polyphosphate in Escherichia coli.

A major impediment to understanding the biological roles of inorganic polyphosphate (polyP) has been the lack of sensitive definitive methods to extract and quantitate cellular polyP. We show that polyP recovered in extracts from cells lysed with guanidinium isothiocynate can be bound to silicate glass and quantitatively measured by a two-enzyme assay: polyP is first converted to ATP by polyP kinase, and the ATP is hydrolyzed by luciferase to generate light. This nonradioactive method can detect picomolar amounts of phosphate residues in polyP per milligram of extracted protein.

Stroke and fibromuscular dysplasia: confirmation by renal magnetic resonance angiography.

Childhood stroke is uncommon and may require extensive evaluation to elucidate an underlying cause. A 9-year-old boy had clinical and magnetic resonance imaging (MRI) features of an ischemic event in the left middle cerebral artery territory. Magnetic resonance angiography (MRA) revealed beading of the left middle cerebral artery, consistent with irregular blood flow secondary to turbulence or luminal narrowing.

Alginate, inorganic polyphosphate, GTP and ppGpp synthesis co-regulated in Pseudomonas aeruginosa: implications for stationary phase survival and synthesis of RNA/DNA precursors.

The regulatory protein AlgR2 in Pseudomonas aeruginosa positively regulates nucleoside diphosphate kinase (Ndk) and succinyl-CoA synthetase, enzymes critical in nucleoside triphosphate (NTP) formation. AlgR2 positively regulates the production of alginate, GTP, ppGpp and inorganic polyphosphate (poly P). An algR2 mutant with low levels of these metabolites has them restored by introducing and overexpressing either the algR2 or the ndk gene into the algR2 mutant.

IgM anti-sulfatide autoantibodies: patterns of binding to cerebellum, dorsal root ganglion and peripheral nerve.

Anti-sulfatide antibodies are associated with polyneuropathies having a prominent sensory component, but with variable degrees of motor and sensory loss, gait dysfunction and demyelination. In this study, we asked whether patterns of IgM binding to neural tissue in anti-sulfatide serums also demonstrated heterogeneity. We used immunocytochemical methods to examine IgM binding to peripheral nerve, dorsal root ganglion, and cerebellum in 41 serums with high titers of IgM anti-sulfatide antibodies.

Inorganic polyphosphate and the induction of rpoS expression.

Inorganic polyphosphate [poly(P)] levels in Escherichia coli were reduced to barely detectable concentrations by expression of the plasmid-borne gene for a potent yeast exopolyphosphatase [poly(P)ase]. As a consequence, resistance to H2O2 was greatly diminished, particularly in katG (catalase HPI) mutants, implying a major role for the other catalase, the stationary-phase KatE (HPII), which is rpoS dependent. Resistance was restored to wild-type levels by complementation with plasmids expressing ppk, the gene for PPK [the polyphosphate kinase that generates poly(P)].

Enhanced generation of monocyte tissue factor and increased plasma prothrombin fragment1+2 levels in patients with polycythemia vera: mechanism of activation of blood coagulation.

Polycythemia vera (PV) is associated with a high incidence of thrombosis. The association of apparent and secondary polycythemia with thrombosis is not clear. It was suggested that activation of the coagulation system contributes to thrombus formation in PV.

Guanosine tetra- and pentaphosphate promote accumulation of inorganic polyphosphate in Escherichia coli.

High levels of guanosine tetraphosphate (ppGpp) and guanosine pentaphosphate (pppGpp), generated in response to amino acid starvation in Escherichia coli, lead to massive accumulations of inorganic polyphosphate (polyP). Inasmuch as the activities of the principal enzymes that synthesize and degrade polyP fluctuate only slightly, the polyP accumulation can be attributed to a singular and profound inhibition by pppGpp and/or ppGpp of the hydrolytic breakdown of polyP by exopolyphosphatase, thereby blocking the dynamic turnover of polyP. The Ki values of 10 microM for pppGpp and 200 microM for ppGpp are far below the concentrations of these nucleotides in nutritionally stressed cells.

Polyphosphate kinase as a nucleoside diphosphate kinase in Escherichia coli and Pseudomonas aeruginosa.

Generation of a wide variety of nucleoside (and deoxynucleoside) triphosphates (NTPs) from their cognate nucleoside diphosphates (NDPs) is of critical importance in virtually every aspect of cellular life. Their function is fulfilled largely by the ubiquitous and potent nucleoside diphosphate kinase (NDK), most commonly using ATP as the donor. Considerable interest is attached to the consequence to a cell in which the NDK activity becomes deficient or over-abundant.

Phosphohistidyl active sites in polyphosphate kinase of Escherichia coli.

In the synthesis of inorganic polyphosphate (polyP) from ATP by polyphosphate kinase (PPK; EC 2.7.4.

Selective staining of the cerebellar molecular layer by serum IgG in Miller-Fisher and related syndromes.

During 1 year, we used immunocytochemical staining of human cerebellum to screen 1,488 serums for IgG autoantibodies to Hu and Yo antigens. Three serums had none of the classically described patterns of IgG binding but instead, selectively stained the cerebellar molecular layer. Evaluation of clinical data showed that the patients had either typical Miller Fisher syndrome (MFS) or Guillain-Barré syndrome with ophthalmoplegia.

Endopolyphosphatases for long chain inorganic polyphosphate in yeast and mammals.

Whereas exopolyphosphatases have been purified from yeast and a variety of bacteria, this is the first report characterizing endopolyphosphatases that act on long chain inorganic polyphosphate (polyP). The activity from Saccharomyces cerevisiae, localized in vacuoles, has been purified to homogeneity from a strain that possesses vacuolar proteases. The endopolyphosphatase is a dimer of 35-kDa subunits.

Childhood chronic inflammatory demyelinating neuropathies: clinical course and long-term follow-up.

Chronic inflammatory demyelinating neuropathy (CIDP) is a rare disease in childhood. We reviewed the clinical characteristics, response to therapy, and long-term prognosis in 13 children (1.5 to 16 years of age) diagnosed with CIDP at Washington University Medical Center, St.

Inorganic polyphosphate supports resistance and survival of stationary-phase Escherichia coli.

The Escherichia coli mutant (ppk) lacking the enzyme polyphosphate kinase, which makes long chains of inorganic polyphosphate (poly P), is deficient in functions expressed in the stationary phase of growth. After 2 days of growth in a medium limited in carbon sources, only 7% of the mutants survived compared with nearly 100% of the wild type; the loss in viability of the mutant was even more pronounced in a rich medium. The mutant showed a greater sensitivity to heat, to an oxidant (H2O2), to a redox-cycling agent (menadione), and to an osmotic challenge with 2.

Chemistry - the lingua franca of the medical and biological sciences.

Despite a large cultural difference between chemists and biologists, chemistry is becoming the common language for all the biological sciences. Now the challenge is to teach the language of scientific achievement to the public and to our representatives in Washington.

Chronic motor neuropathies and lower motor neurone syndromes.

Immune-mediated motor neuropathies are most often disorders manifest clinically by slowly progressive, asymmetrical, distal weakness, starting in the hands more often than the legs. In some cases, electrophysiological findings show multifocal conduction block along the length of motor axons. Other patients have findings consistent with only axonal loss.

Inorganic polyphosphates in the acquisition of competence in Escherichia coli.

A complex of polyhydroxybutyrate (PHB), Ca2+, and inorganic polyphosphate (polyP) was proposed as the membrane component responsible for competence for DNA entry in Escherichia coli (Reusch, R. N., and Sadoff, H.