Disease relevance of awd

• A Drosophila gene that is homologous to a mammalian gene associated with tumor metastasis codes for a nucleoside diphosphate kinase [1].
• The expression of the Drosophila awd gene during normal development and in neoplastic brain tumors caused by lgl mutations [2].
• Using the same awd reporter gene as a marker of donor cells, we have confirmed the invasiveness of lgl-induced neuroblastomas [2].
• However, rescue of female sterility requires twice as much nm23-H2 expression as awd expression [3].
• Homology was found between the sequence of spinach NDP kinase I and those of the rat, Myxococcus xanthus, and Dictyostelium discoideum NDP kinases, as well as the human Nm23-gene product and the awd protein of Drosophila melanogaster [4].

High impact information on awd

• Neuroblasts in Drosophila larvae homozygous for a null mutation in the awd gene are arrested in metaphase, indicating that microtubule-associated Awd/NDP kinase plays a critical role in spindle microtubule polymerization [1].
• Consistent with this, Btl-GFP chimera expressed from a cognate btl promoter-driven system accumulate at high levels on tracheal cell membrane of awd mutants as well as in awd RNA duplex-treated cultured cells [5].
• Using Drosophila tracheal system as a genetic model, we examined the function of the Drosophila homolog of nm23, the awd gene, in cell migration [5].
• In individuals of the genotype pn; awdK-pn/awd+ the awd mRNA is present at normal levels but the awd polypeptide fails to accumulate [6].
• The third-chromosome mutation Killer of prune (K-pn) causes no phenotype by itself, but causes lethality in individuals homozygous for the nonlethal X-chromosome mutation prune (pn) [6].

Chemical compound and disease context of awd

• Nm23-H1(S120G), found in advanced human neuroblastomas, exhibited deficient activity in several histidine-dependent protein phosphotransfer reactions, including histidine autophosphorylation, downstream phosphorylation on serines, and slightly decreased histidine protein kinase activity; significant NDPK activity was observed [7].

Biological context of awd

• We show that loss of Drosophila awd results in dysregulated tracheal cell motility [5].
• Nucleoside diphosphate kinase (NDK), an enzyme encoded by the Drosophila abnormal wing discs (awd) or human nm23 tumor suppressor genes, generates nucleoside triphosphates from respective diphosphates [8].
• This connection between NDK and membrane internalization further strengthens an emerging hypothesis that endocytosis, probably of activated growth factor receptors, is an important tumor suppressor activity in vivo [8].
• We recovered mutant strains at the high rate of approximately 4.8 mutations/kb for every 1000 mutagenized chromosomes from a screen for new mutations in the Drosophila awd gene [9].
• Drosophila NDP kinase is the product of the abnormal wing disc (awd) developmental gene, a point mutation in which can produce the killer of prune (K-pn) conditional lethal phenotype [10].

Anatomical context of awd

• Nucleoside diphosphate kinase, a source of GTP, is required for dynamin-dependent synaptic vesicle recycling [8].
• The wild-type awd+ gene transcript is most abundant during the second and third larval instars but is found at a lower level during every developmental stage as well as in continuous cell lines [11].
• Import into mitochondria is accompanied by cleavage of the N-terminal extension that results in NDP kinase activity [12].
• A cromoglycate binding protein from rat mast cells of a leukemia line is a nucleoside diphosphate kinase [13].
• Partially purified NDPK from human erythrocytes produced a similar phosphorylation pattern independent of urea addition and also acted stoichiometrically [14].

Associations of awd with chemical compounds

• Following dilution of urea with buffer the urea-denaturated mutant nucleoside diphosphate kinase accumulates as folded monomers and cannot recover its quaternary structure and enzymatic activity [15].
• Mechanism of phosphate transfer by nucleoside diphosphate kinase: X-ray structures of the phosphohistidine intermediate of the enzymes from Drosophila and Dictyostelium [16].
• Nucleoside diphosphate kinase (NDPK) was purified from Drosophila melanogaster by a combination of anion-exchange, hydroxyapatite, and reversed-phase chromatography [17].
• The null mutant phenotype cannot be rescued at all by a transgene that has 750 bp of awd upstream regulatory DNA fused to a full-length awd cDNA with a mutation that eliminates NDP kinase activity by replacement of the active site histidine with alanine [3].
• Nm23-H1(P96S), a Drosophila developmental mutation homolog, exhibited normal autophosphorylation and nucleoside-diphosphate kinase (NDPK) characteristics but deficient phosphotransfer activity in three histidine protein kinase assays, using succinic thiokinase, Nm23-H2, and GST-Nm23-H1 as substrates [7].

Other interactions of awd

• Among the five ICs in Ciona, three are orthologs of those in sea urchin dynein: two are WD-repeat proteins and the third one, unique to metazoan sperm flagella, contains both thioredoxin and nucleoside diphosphate kinase modules [18].
• Thus, it is very suggestive to regard the synthetic lethal system prune/Killer-of-prune as the Drosophila model for human neurofibromatosis [19].
• Dephosphorylation of NDP kinase by bacterial alkaline phosphatase increased NDP kinase activity [20].

Analytical, diagnostic and therapeutic context of awd

• We have examined the tissue-specific transcription of the awd gene by RNA in situ hybridization and by reporter gene expression [2].
• NDP kinase from Dictyostelium was mutated by site-directed mutagenesis at positions indicated by structural data to be involved in the trimer interface [21].
• Nucleoside diphosphate kinase. Investigation of the intersubunit contacts by site-directed mutagenesis and crystallography [21].
• Crystallization and preliminary X-ray diffraction studies of nucleoside diphosphate kinase from Dictyostelium discoideum [22].
• Gel filtration and Hill plot analysis indicate that the purified NDP kinase forms a tetramer and shows little interaction among substrates [20].

References