Disease relevance of AK3

• By targeting human factor IX (hFIX) expression to late-stage erythropoiesis, we achieve long-term hFIX secretion at levels significantly higher (>tenfold) than those obtained with an archetypal ubiquitous promoter in a mouse model of hemophilia B [1].
• We demonstrate here that vascular and hepatic delivery of a third-generation HIV-derived lentiviral vector encoding human Factor IX (LV-hFIX) produced potentially therapeutic serum levels of hFIX protein with no vector-mediated local or systemic toxicity of adult mice [2].
• We used the integrase from phage phiC31 to integrate the human Factor IX (hFIX) gene permanently into specific sites in the mouse genome [3].
• Myoblast-mediated gene transfer and its repeated applications were tested for achieving a long-term stable systemic production of human factor IX (hFIX) at a therapeutic level in SCID mice [4].
• To determine the most robust human coagulation factor IX (hFIX) expression cassette in an adenovirus, we first tested different hFIX expression sequences with or without flanking MARs in first-generation adenoviral vectors [5].

High impact information on AK3

• The purified protein had an identical molecular mass (nonreduced) to platelet membrane GMP-140 (approximately 3 kD lower, reduced) and was immunoblotted by polyclonal anti-GMP-140, and the anti-GMP-140 monoclonal antibodies AK4 and AK6 [6].
• A plasmid containing attB and an expression cassette for hFIX was delivered to the livers of mice by using high-pressure tail vein injection [3].
• Portal vein administration produced the highest serum levels of hFIX and demonstrated proportionally higher levels of gene transfer to the liver with up to 4% of hepatocytes expressing hFIX [2].
• Fluorescence microscopy showed that human AK6 is localized predominantly to the nucleus of HeLa cells [7].
• Neonatal hemophilia B mice that received different amounts of RV achieved stable and dose-related expression of hFIX without anti-hFIX antibody formation [8].

Chemical compound and disease context of AK3

• METHODS: Hydrodynamics-based naked DNA plasmid administration was performed by tail vein injection of 10 microg of pCMV- hFIX and chloroquine (0, 100, 200, and 500 micromol/L) in 2.2 mL of Ringer's solution within 6-7 s, the level and stability of hFIX expression, liver damage and toxicity were then examined [9].

Biological context of AK3

• Genomic Southern analysis suggested that multiple AK3 loci exist in the human genome, including one located in an intron of NF1 on chromosome 17 [10].
• A database search revealed striking homology, about 58% amino acid sequence identity, between this predicted protein and bovine AK3 [10].
• However, three isozymes, AK1, AK2 and AK3, have been characterized in mammalian cells and shown to be localized in the cytosol, mitochondrial intermembrane space and mitochondrial matrix, respectively, and it is unknown which one of these isozymes accumulates in the cytosol during apoptosis [11].
• These findings demonstrate for the first time a gene dosage effect for AK3 in a case of 9p trisomy and show again that gene mapping information can be used to define partial aneuploidies in fetal fibroblasts [12].
• In contrast to its human orthologue (AK3), PfGAK contains a zinc finger motif and binds ionic iron [13].

Anatomical context of AK3

• AK3 is expressed in all tissues except for red blood cells indicating that AK3 gene is a housekeeping-type gene [14].
• Somatic cell hybrid studies indicate that the AK3 locus is not syntenic with that of AK2 (chromosome 1) [15].
• After intramuscular injection of 5, 10, and 20 x 10(6) myoblasts, SCID mice stably produced hFIX into the systemic circulation proportional to the number of implanted cells, and the expression levels were maintained for at least up to 10 months (end of the experiment) [4].
• Interestingly, systemic administration of 2 x 1012 vector particles of AAV-1, -4, or -6 resulted in hFIX levels similar to those achieved by portal vein delivery [16].
• Primary skeletal myoblasts were stably transfected with a hFIX expression plasmid vector, pdLMe4 betaA-hIXm1, which contains a hFIX minigene under the control of a beta-actin promoter with muscle creatine kinase enhancers [4].

Associations of AK3 with chemical compounds

• The AK3 isozymes show activity with either GTP + AMP or ITP + AMP but do not show activity with ATP + AMP [15].
• No NH2-terminal presequence of mitochondrial targeting was identified in AK3 from the sequencing and expression analyses of the cDNA [17].
• This tentative diagnosis could be confirmed by demonstration of gene dosage effects for galactose-1-phosphate uridyl transferase (GALT, EC 2.7.7.12) and nucleoside triphosphate adenylate kinase (AK3, EC 2.7.4.10) both known to be controlled by genes assigned to 9p [12].
• The contact angles measured using a goniometer on A, AA, AA61, AK3, AK3 61 MS were 20, 34.8, 71, 29 and 80 degrees, respectively whereas those MS coated with PLL were 49.7, 55.8, 91, 48.25 and 84.4 degrees, respectively [18].
• The formulations examined were: alginate alone (A), alginate with methylcellulose (AA) AA with Pluronic L61 (AA61), alginate with hydroxypropyl methylcellulose (AK3), and AK3 with Pluronic (L61 (AK3 61) [18].

Other interactions of AK3

• AK2 is expressed in the intermembrane space, while AK3 and AK4 are localized in the mitochondrial matrix [14].
• AK2, AK3 and AK4 are mitochondrial proteins [14].
• The AK3 locus is however, probably syntenic with the AK1 locus, on chromosome 9 [15].
• Demonstration of gene dosage effects for AK3 and GALT in fibroblasts from a fetus with 9p trisomy [12].
• There was an imperfect correlation between the expression of alpha 1 AT and of the two chromosome 9 marker enzymes AK1 and AK3 (two discordant clones) [19].

Analytical, diagnostic and therapeutic context of AK3

• Western-blot analysis demonstrated expression profiles of AK3 and AK4 that were similar to their mRNA expression patterns in each tissue [20].
• Sequence analyses revealed that human AK6 belongs to a distinct subfamily of AKs present in all eukaryotic organisms sequenced so far [7].
• The mean volume sizes of A, AA, AA61, AK3, AK3 61 microspheres (MS) were 11, 10.5, 3.8, 8.7 and 3.9 mocrom, respectively [18].
• When an integrase expression plasmid was co-injected, hFIX serum levels increased more than tenfold to approximately 4 microg/ml, similar to normal FIX levels, and remained stable throughout the more than eight months of the experiment. hFIX levels persisted after partial hepatectomy, suggesting genomic integration of the vector [3].
• For a given dose, intraportal administration of rAAV CAGG-FIX resulted in a 1.5-fold or 4-fold higher level of hFIX compared to tail vein or intramuscular injections, respectively [21].

References