Disease relevance of ACTG1

• A mutation in the gamma actin 1 (ACTG1) gene causes autosomal dominant hearing loss (DFNA20/26) [1].
• This purified yeast CCT was used for a novel quantitative actin-folding assay with human beta-actin or yeast ACT1p protein folding intermediates, Ac(I), pre-synthesised in an Escherichia coli translation system [2].
• Immunohistochemical analysis revealed that alpha-enolase and beta-actin were present at extremely low levels in the epithelial superficial and wing cells of the keratoconus corneas compared to these cells of normal corneas [3].
• 5. We now show that plasminogen binds to prostate cancer cells and that the binding colocalizes with surface beta-actin, but AS4.5 does not bind to the cell surface [4].
• To test this hypothesis, rAAV vectors containing the hAAT cDNA driven by either the human elongation factor 1 alpha promoter, the human cytomegalovirus immediate-early promoter (CMV), or the CMV-chicken beta actin hybrid (CB) promoter were injected into the portal or tail veins of adult C57Bl/6 mice [5].

High impact information on ACTG1

• Toxoplasmic encephalitis in patients with the acquired immunodeficiency syndrome. Members of the ACTG 077p/ANRS 009 Study Team [6].
• Health status and function with zidovudine or zalcitabine as initial therapy for AIDS. A randomized controlled trial. Roche 3300/ACTG 114 Study Group [7].
• After beta-actin, the cytosolic brain isoform of creatine kinase was the next most abundant bundle protein; at approximately 0.5 mM, creatine kinase is capable of maintaining high ATP levels despite 1 mM/s ATP consumption by the plasma-membrane Ca(2+)-ATPase [8].
• METHODS: Co-infected patients were randomized within a US multicenter trial (ACTG 5071) to receive pegylated-interferon (PEG-IFN) alfa-2a + ribavirin vs. IFN alfa-2a + ribavirin [9].
• Didanosine and ACTG 116A [10].

Chemical compound and disease context of ACTG1

• Interestingly, this repressive ACTG motif is found in the human immunodeficiency virus promoter, the activity of which is also suppressed by tannic acid (Uchiumi, F., Maruta, H., Inoue, J., Yamamoto, T., and Tanuma, S. (1996) Biochem. Biophys. Res. Commun. 220, 411-417) [11].
• OBJECTIVES: To evaluate the impact of the modified ACTG 076 zidovudine regimen on the risk for vertical HIV transmission [12].
• Phase II dose-ranging trial of foscarnet salvage therapy for cytomegalovirus retinitis in AIDS patients intolerant of or resistant to ganciclovir (ACTG protocol 093). AIDS Clinical Trials Group of the National Institute of Allergy and Infectious Diseases [13].
• The AIDS Clinical Trials Group Study 850 (ACTG 850) evaluated the penetration of zidovudine (ZDV), lamivudine (3TC), and amprenavir (APV), given alone and in combination with the 2 nucleoside analogues, into the male genital tract, because these factors may affect human immunodeficiency virus (HIV) type 1 suppression and transmission [14].
• Delavirdine susceptibilities and associated reverse transcriptase mutations in human immunodeficiency virus type 1 isolates from patients in a phase I/II trial of delavirdine monotherapy (ACTG 260) [15].

Biological context of ACTG1

• Sequence analysis of the gamma-actin gene (ACTG1) revealed missense mutations in highly conserved actin domains in all four families [16].
• FISH localization of human cytoplasmic actin genes ACTB to 7p22 and ACTG1 to 17q25 and characterization of related pseudogenes [17].
• Human beta- and gamma-cytoplasmic actin genes (ACTB and ACTG1) were mapped to chromosomes 7p22 and 17q25, respectively, by fluorescence in situ hybridization (FISH) [17].
• These findings strongly suggest that the Thr278Ile mutation in ACTG1 represents the first disease causing germline mutation in a cytoplasmic actin isoform [1].
• Haplotype analysis refines the DFNA20 critical region to 12 cM between D17S1806 and D17S668 [18].

Anatomical context of ACTG1

• The 6-cM critical region harboured the gamma-1-actin (ACTG1) gene, which was considered an attractive candidate gene because actins are important structural elements of the inner ear hair cells [1].
• Two other cytoskeletal proteins, beta-actin and alpha-tubulin, clustered at the cell leading edge and uropod, respectively, of polarized lymphocytes [19].
• While beta-actin concentrates preferentially at the cell's leading edge, the motor protein myosin II and a microtubule organizing center (MTOC) are packed in the uropod [20].
• Coimmunoprecipitation experiments using HSMCs, NIH-3T3 cells, and human prostate tissue lysates further demonstrated that HDAC8 associates with alpha-SMA but not with beta-actin [21].
• CONCLUSIONS: The results showed relatively low or negligible levels of alpha-enolase and beta-actin in the wing and superficial epithelial cells of keratoconus corneas compared to normal corneas [3].

Associations of ACTG1 with chemical compounds

• These proteins include the following: integrin alpha-4, myosin heavy chain (nonmuscle type A), myosin light-chain alkali (nonmuscle isoform), and beta-actin [22].
• In contrast, the induction of fibronectin, beta-actin, and type I procollagen (synthesized only in WI-38 cells) was abrogated by cycloheximide [23].
• beta-Tubulin Is a More Suitable Internal Control than beta-Actin in Western Blot Analysis of Spinal Cord Tissues after Traumatic Injury [24].
• Differentiation studies indicated an increase in alpha-smooth muscle actin expression relative to beta-actin (western blotting), with cytochemistry confirming that all doses of RAD and LY294002 increased the proportion of alpha-smooth muscle actin positive cells, and hence myofibroblasts [25].
• Chrysotile asbestos, but not RCF-1, increased endothelial cell uPA message, relative to changes in beta-actin mRNA [26].

Physical interactions of ACTG1

• Immunoprecipitation using antibodies against annexin V copurify annexin V and gamma- but not beta-actin from activated platelets [27].

Regulatory relationships of ACTG1

• Stable expression of human tissue-type plasminogen activator regulated by beta-actin promoter in three human cell lines: HeLa, WI-38 VA13 and KMS-5 [28].

Other interactions of ACTG1

• Fluorescence in situ hybridization analysis and genomic clone sequencing indicate that the FSCN2 gene lies within 200 kb of the actin gene ACTG1 at 17q25 [29].
• The USH1G interval overlaps the intervals for two dominant forms of isolated hearing loss, namely DFNA20 and DFNA26 [30].
• Already after 24 h the relative amount of mRNA of thymosin beta4 and beta-actin was greatly reduced to 71 and 58%, respectively [31].
• Based on the results, two proteins, alpha-enolase and beta-actin, were further analyzed by immunohistochemical and western blot methods, using respective antibodies [3].
• Median TS/beta-actin was 2.51 (range 0.98-7.07) [32].

Analytical, diagnostic and therapeutic context of ACTG1

• Real-time quantitative RT-PCR reactions using conventional, non-RNA-specific primers on saliva samples yielded PCR products for 36B4, beta-actin, and GAPDH; DNase-treated saliva samples did not yield a PCR product, and the "no-RT" and "+RT" conditions yielded similar amounts of PCR product [33].
• Confirmatory RT-PCR experiments used conventionally designed PCR primer pairs for the reference housekeeper transcripts encoding 36B4, beta-actin, and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA sequences, which are known to be homologous to genomic DNA pseudogene sequences [33].
• PAI-1 mRNA levels, determined by Northern blot analysis and expressed relative to beta-actin mRNA levels, were very similar for HUVEC cultured in the absence or the presence of rt-PA or rt-PA-Ala478 [34].
• Each value was related to the corresponding beta-actin value to allow quantitative evaluation [35].
• In isoelectric focusing and two-dimensional gel electrophoresis beta-actin was the most prominent of the 3 actin isoforms in all cases [36].

References