High impact information on Aph-4

• Phosphorylation stimulated the DNA relaxation activity of topoisomerase II by 3-fold over that of the dephosphorylated enzyme, and the effects of modification could be reversed by treatment with alkaline phosphatase [1].
• Such single-stranded DNA protein complexes have been tested for blot hybridization using two colorimetrically detectable enzymes, namely peroxidase and alkaline phosphatase, as the protein moiety of the probe [2].
• Amphipathic enzymes, invertase (EC 3.2.1.26), 8-amylase (EC 3.2.1.3), and alkaline phosphatase (EC 3.1.3.1), were purified from the rat small intestinal mucosa as trypsin and Triton forms, the catalytic and regulatory characteristics of which were compared in rats and in drosophila [3].
• The nearer encodes Aph-4, the first Drosophila alkaline phosphatase gene to be identified; the more distant gene [l(3)96601] is novel, with a head-elevated expression, and with distant similarity to transcription regulatory elements [4].
• The promoter region of the liver/bone/ kidney-type alkaline phosphatase gene was examined to define the cis-acting regulatory sequences and transcription factors responsible for its expression in hematopoietic cells [5].

Biological context of Aph-4

• Wild females from Missouri and Louisiana populations heterozygous at the APH locus carried more sperm at capture than did the corresponding homozygotes [6].
• This heterotic association was significant for the combined samples, and whether it was the result of heterosis at the enzyme locus studied, or due to geographically widespread close linkage with other heterotic loci, it should help to maintain heterozygosity at the APH locus [6].
• A comparison of the sex-linked APH genotypes of wild females with those of their daughters indicated that among 295 wild-inseminated females from five populations, 35% had mated more than once, and of this 35%, six females had mated at least three times [6].
• Furthermore, the activation of ATP hydrolysis was reversed following treatment of phosphorylated topoisomerase II with alkaline phosphatase [7].
• The APH locus is on the inversion-free X chromosome; the chromosomal locus of the autosomal ACPH is unknown, and could involve inversion polymorphism [6].

Anatomical context of Aph-4

• The direct actions of Shh and Ihh on stimulation of osteoblast differentiation are evidenced by the findings that these factors stimulate alkaline phosphatase activity in cultures of pluripotent mesenchymal cell line cells and osteoblastic cells and that these cells express putative receptors of hedgehog proteins [8].
• On affinity blots the AP-SP probe binds to membrane proteins extracted from abdomen and head plus thorax, respectively [9].
• A conserved domain of alkaline phosphatase expression in the Malpighian tubules of dipteran insects [10].

Associations of Aph-4 with chemical compounds

• The double-label in situ hybridization method involves digoxigenin- and biotin-labeled DNA probes that are processed to result in blue alkaline phosphatase and brown peroxidase reaction products, respectively [11].
• One transcript is hybridized with a biotin-labeled RNA probe and visualized as a brown peroxidase reaction product, and the other transcript is hybridized with a digoxigenin-labeled RNA probe and visualized as a blue alkaline phosphatase reaction product [12].

Other interactions of Aph-4

• Genetic fusion of 16 and 14 amino acid segments of c-Cbl and Sos, respectively, to bacterial alkaline phosphatase confirmed that these segments were potential ligand sites for the C-terminal SH3 domain of CAP [13].
• Dephosphorylation of NDP kinase by bacterial alkaline phosphatase increased NDP kinase activity [14].

Analytical, diagnostic and therapeutic context of Aph-4

• Both in situ hybridization with Aph-4 probes and direct histochemical determination of alkaline phosphatase activity precisely matches the enhancer-trap pattern reported by the original lines [4].
• The labels are visualized in situ by differently colored water-insoluble precipitates using alkaline phosphatase- or beta-galactosidase-based immunoassays [15].

References