Disease relevance of phoA

• Consistent with this notion, the introduction of the E. coli phoA gene in S. flexneri resulted in the induction of alkaline phosphatase synthesis under phosphate limitation [1].
• The isolation of a plaque-forming lambda transducing phage carrying the entire phoA gene is also described [2].
• Self-cloning minitransposon phoA gene-fusion system promotes the rapid genetic analysis of secreted proteins in gram-negative bacteria [3].
• Bacillus subtilis has an alkaline phosphatase multigene family [4].
• Identification of Treponema pallidum subspecies pallidum genes encoding signal peptides and membrane-spanning sequences using a novel alkaline phosphatase expression vector [5].

High impact information on phoA

• Phase variation mediated by the CTCTT repeat also occurred in E. coli, as assayed with a P.II-alkaline phosphatase (phoA) gene fusion [6].
• Four of these bands aligned with the major tau bands found in adult human cerebral cortex following perchloric acid extraction and alkaline phosphatase treatment [7].
• Based on the refined crystal structure of E. coli alkaline phosphatase, it appears that the active site and the core of the structure are retained in both Bacillus alkaline phosphatases [4].
• Bacillus subtilis alkaline phosphatases III and IV. Cloning, sequencing, and comparisons of deduced amino acid sequence with Escherichia coli alkaline phosphatase three-dimensional structure [4].
• Neither Bacillus alkaline phosphatase sequenced contains any cysteine residues, an amino acid implicated in intrachain disulfide bond formation in other alkaline phosphatases [4].

Chemical compound and disease context of phoA

• Using homopolymeric units of either isoleucine, leucine, valine or alanine to replace the natural core segment of the Escherichia coli alkaline phosphatase signal peptide, the hydrophobicity requirements for export and processing were delineated [8].
• Endotoxemia for 6 h in rats or 16 h in mice resulted in liver injury/dysfunction (increase in the serum levels of aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, alkaline phosphatase, bilirubin), renal dysfunction (creatinine), and pancreatic injury (lipase, amylase) [9].
• The membrane topology of the plasmid-encoded Pseudomonas aeruginosa ChrA protein, which effluxes chromate ions, was determined by the analysis of translational fusions with reporter enzymes alkaline phosphatase and beta-galactosidase [10].

Biological context of phoA

• A number of mutant alleles affecting the Pst phosphate transport system have been divided into three complementation groups on the basis of constitutive alkaline phosphatase activity in appropriate partial diploid strains [11].
• Heterodimeric alkaline phosphatases were created using two methods: (1) in vitro formation by dissociation at acid pH followed by reassociation at slightly alkaline pH conditions in the presence of zinc and magnesium ions; and (2) in vivo expression from a plasmid carrying two different phoA genes [12].
• In addition, the phoR gene product acts as a negative regulator.--We describe a model for phoA gene expression consistent with this new evidence [13].
• Use of gene fusions to determine the orientation of gene phoA on the Escherichia coli chromosome [14].
• We present genetic evidence which demonstrates that the phoA gene is transcribed in the clockwise direction on the Escherichia coli chromosome, in contrast to an earlier proposal [14].

Anatomical context of phoA

• One mutant selected for its impaired ability to invade epithelial cells had an insertion of a Tn phoA transposon within the nlpI gene encoding the lipoprotein NlpI [15].
• Repressive effect of imbalance in the phospholipid composition and total charge of membranes of Escherichia coli on the phoA gene transcription [16].
• The alkaline phosphatase activity increased drastically when positive charges were introduced, indicating that the SecY domain fused to PhoA showed a change in localization from the cytoplasm to the periplasm [17].
• PLA2-stimulating activity is greatly enhanced after exposing isolated ganglia to phorbol dibutyrate (PDBu) and is reduced by treatment with immobilized E. coli alkaline phosphatase [18].

Associations of phoA with chemical compounds

• Alkaline phosphatase synthesis was initiated by a temperature shift in a strain carrying a phoA amber mutation and a temperature-sensitive suppressor mutation; acid hexose phosphatase was studied after relief of catabolite repression [19].
• We have used gene fusions between mtlA (encoding the permease) and 'phoA (encoding alkaline phosphatase lacking its signal sequence) to further investigate the topology of the mannitol permease [20].
• T. pallidum-AP fusion proteins which partitioned into the hydrophobic detergent phase but did not incorporate palmitate were also identified [5].
• Triton X-114 detergent phase partitioning of individual T. pallidum-AP fusions revealed several clones whose AP activity partitioned preferentially into the hydrophobic detergent phase [5].
• The alkaline phosphatase (AP) superfamily is an ideal system to use in making such comparisons given the extensive data available on both nonenzymatic and enzymatic phosphoryl transfer reactions [21].

Other interactions of phoA

• The orientation of phoA and the exact position of its N-terminal end on this map were determined by identifying a subfragment which carried the phoA promoter and by determining the nucleotide sequence of a 160 bp portion of this subfragment comprising the codons for the N-terminal end of pre-alkaline phosphatase [22].

Analytical, diagnostic and therapeutic context of phoA

• Western blot analysis demonstrated the presence of a correctly size 110-kDa fusion protein in the culture supernatant, which reacted with both anti-Act and anti-alkaline phosphatase antibodies [23].
• Use of metal chelate affinity chromatography for removal of zinc ions from alkaline phosphatase from Escherichia coli [24].
• A comparison of alkaline phosphatase and radiolabelled gene probes with bioassays for enterotoxigenic Escherichia coli [25].
• Through error-prone PCR both in the coding sequence and the regulatory sequence of E. coli alkaline phosphatase, the cellular enzyme activity has been efficiently enhanced [26].
• All the new constructs retained almost equal activity and high affinity for their target antigen, placental alkaline phosphatase (PLAP), compared to the intact MAb H7, up to +42 degrees C as evaluated by ELISA [27].

References