Disease relevance of ACTB

• While B2M and ACTB exhibited comparable levels of expression within different grades of astrocytomas and meningiomas, GAPD showed an inverse pattern in these tumors [1].
• Beta-actin in human colon adenocarcinoma cell lines with different metastatic potential [2].
• A recombinant phage that carries the cytoplasmic beta-actin gene was isolated from a human DNA library [3].
• Northern analysis indicated that ER mRNA levels were increased 1.4-to 12.6-fold in leiomyoma compared with myometrium in all patients examined (n = 11), whereas beta-actin mRNA was not different between the two groups [4].
• A role for Rev in the association of HIV-1 gag mRNA with cytoskeletal beta-actin and viral protein expression [5].

Psychiatry related information on ACTB

• METHODS: We employed SDS-PAGE and Western blotting to measure levels of GAD isomers 65 and 67 kDa and Reelin isoforms 410-, 330- and 180-kDa proteins as well as beta-actin in cerebellum of subjects with schizophrenia, bipolar disorder and major depression vs. controls (N = 15 per group) [6].
• A probe specific for the INT-2 gene was labelled with [alpha-32P]dCTP and a probe to beta-actin, the control locus, was labelled with [alpha-35S]dATP [7].
• These studies demonstrated the presence of protein carbonyl immunoreactivity in beta-tubulin, beta-actin and creatine kinase BB in Alzheimer's disease and control brain extracts [8].

High impact information on ACTB

• Recently, beta-actin was found to be a component of mammalian SWI/SNF-like BAF chromatin remodeling complexes and still more recently other SWI/SNF-related chromatin remodeling complexes in yeast, flies, and man [9].
• Expression of this factor in CV1 cells shows that it represses expression originating from both the EGFR and beta-actin promoters as well as chimeric promoters containing the CANP gene [10].
• A variant form of beta-actin in a mutant of KB cells resistant to cytochalasin B [11].
• Furthermore, this sarcomeric protein partitions between the Triton X-100 insoluble and soluble phases to the same extent as the endogenous beta-actin [12].
• Variations in expression of mutant beta actin accompanying incremental increases in human fibroblast tumorigenicity [13].

Chemical compound and disease context of ACTB

• In an attempt to identify the changes induced in the synthesis of cytoskeletal protein by ischemia, we also evaluated the effects of post-ischemia administration of bifemelane on these cytoskeletal proteins. alpha-Tubulin and beta-actin mRNAs were decreased in the CA1 region 14 days after transient ischemia [14].
• These findings in the baboon model of alcoholic fibrosis show that ethanol consumption increases type I procollagen mRNA, which may foster fibrogenesis; increases albumin mRNA content without causing an increase in serum albumin; and induces no change in levels of beta-actin mRNA [15].
• We conclude the NAC blocks dense cell formation and ISC formation by targeting channels involved in cellular dehydration and beta-actin, respectively [16].
• Accordingly, we analyzed 108 colorectal adenomas for COX-1 and COX-2 transcription in archival formalin-fixed, paraffin-embedded tissue using by real-time PCR and normalized to beta-actin [17].
• Primary Schwann cells were infected in vitro with a recombinant retrovirus expressing a dominant selectable marker, neomycin phosphotransferase (conferring resistance to the drug G418), and antisense P0 RNA under the control of the human beta-actin promoter [18].

Biological context of ACTB

• Herein, we present a new mechanism of GLI activation through fusion with the beta-actin gene (ACTB) in five histologically distinctive soft tissue tumors showing a t(7;12)(p21-22;q13-15) and a pericytic phenotype [19].
• Molecular genetic analysis showed that the translocation in all cases resulted in a fusion transcript including the 5'-part of ACTB and the 3'-part of GLI [19].
• The significant differences between B2M, ACTB and GAPD transcript levels brings into question the common practice of defining gene expression as a ratio between the transcripts of interest and those of these reference genes [1].
• FISH localization of human cytoplasmic actin genes ACTB to 7p22 and ACTG1 to 17q25 and characterization of related pseudogenes [20].
• Human beta- and gamma-cytoplasmic actin genes (ACTB and ACTG1) were mapped to chromosomes 7p22 and 17q25, respectively, by fluorescence in situ hybridization (FISH) [20].

Anatomical context of ACTB

• 18S rRNA varies less among the cell lines but has a higher degree of random variability, while ACTB mRNA varies more among cell lines but has a lower degree of random variation [21].
• ACTB and HPRT1 are suitable internal controls for evaluating mRNA expression levels in primary cultures of human and rat hepatocytes after Rif, Dex, or Ome exposure [22].
• No differences were detected in the apparent amounts of RT-PCR products when comparing GC with CC, suggesting a similar pattern of expression of these RNAs. beta-actin mRNA was detected in spermatozoa, but TRalpha-1 expression was not detectable [23].
• An important increase in the variation of beta-actin expression was observed in cultured cells as compared to fresh cells [24].
• In the present study, a frequently used control gene, beta-actin, was examined in ovine heart valves to evaluate its applicability as a housekeeping gene for this tissue [24].

Associations of ACTB with chemical compounds

• The second class encodes beta actin, and the longest such clone contains 45 base pairs of 5' untranslated region plus the remainder of the mRNA extending to the polyadenylic acid tail [25].
• LPS treatment resulted in the rapid elevation of IL-1beta and TNF-alpha mRNA levels relative to beta-actin mRNA at 1 h, with a subsequent slight decrease at 3 h after the treatment, while the down-regulation of the relative concentration of MDR1 mRNA was found at 3 h, not at 1 h, after LPS treatment [26].
• Three polymorphisms in intron 3 (T>C) and one polymorphism in exon 4 (T>C) of porcine ACTB gene were identified by comparative sequencing of animals of the breeds Pietrain and Hampshire. Association analysis revealed that haplotypes affected the variation of the traits MOT, ASR and NBA [27].
• In contrast to the human cardiac muscle actin gene, the aorta-type smooth muscle actin gene, and the stomach-type smooth muscle actin gene, the beta-actin gene lacks the codon for cysteine between the ATG initiation codon and the codon for the NH2-terminal amino acid of the mature protein [3].
• Sequencing of the clones demonstrated a G-1174 to A substitution, predicting a glutamic acid-364 to lysine substitution in beta-actin and eliminating a HinfI DNase restriction site found in normal beta-actin sequence [28].

Physical interactions of ACTB

• We also determined that the region between amino acids 613 and 723 of PLD2 is required for the direct binding of beta-actin, using bacterially expressed glutathione S-transferase fusion proteins of PLD2 fragments [29].
• N-acetyl-(leucyl)2-norleucinal and E64, two specific inhibitors of the calcium-activated protease, calpain I, protect ezrin binding to beta actin in the presence of calcium [30].
• EGF also stabilizes beta-tubulin and beta-actin mRNAs but has very little effect on the degradation of total mRNA [31].
• Second, by the use of denatured labeled beta-actin and beta-tubulin as model substrates for binding to CCT, we demonstrate that the CCT particle can contain two substrate protein chains simultaneously [32].
• There was more beta-actin coimmunoprecipitated with eNOS in Triton X-100-soluble fraction in confluent cells in later growth phase and in high density [33].

Regulatory relationships of ACTB

• This assay also demonstrates that beta-actin stimulates transcription by RNA polymerase II [34].
• CONCLUSIONS: Our data demonstrate that beta-actin as a transcription factor stimulates eNOS expression; and the transcriptional effect appears to be 27nt-dependent [35].
• Intriguingly, purified beta-actin potently inhibited both phosphatidylinositol-4,5-bisphosphate- and oleate-dependent PLD2 activities in a concentration-dependent manner (IC50 = 5 nm) [29].
• Quantification of ER-beta mRNA was performed by real-time quantitative RT-PCR with results expressed as a percentage of beta-actin mRNA [36].
• PDGF-induced beta-actin mRNA redistribution was inhibited by the tyrosine kinase inhibitor herbimycin, indicating that this process requires intact tyrosine kinase activity, similar to actin filament polymerization and chemotaxis [37].

Other interactions of ACTB

• Comparison of the expression of MAGE mRNA with that of beta-actin mRNA showed that it is expressed in amounts equal to about and at least one-fifth that of beta-actin [38].
• Hybridization was carried out between plerocercoid DNA and cDNAs for human beta-actin, alpha-tubulin and growth hormone (hGH) [39].
• Widely used normalizing genes include beta-actin and glyceraldehyde-3-phosphate dehydrogenase [40].
• The ratio of ER beta mRNA to beta-actin mRNA expression was significantly reduced in non-functioning pituitary tumors (NFTs; 0.92 +/- 0.09; mean +/- SE; n = 23) compared with findings in normal pituitaries (1.56 +/- 0.21; mean +/- SE; n = 5; p < 0.05 Student's t-test) [41].
• Furthermore, the eNOS expression was reduced when beta-actin gene was silenced by specific siRNA, and actin overexpression upregulated eNOS expression >3-fold [35].
• Together our data establish that the posttranscriptional event involving HuR-mediated beta-actin mRNA stabilization could be a part of the regulatory mechanisms responsible for maintaining cell integrity, which is a prerequisite for avoiding transformation and tumor formation [42].

Analytical, diagnostic and therapeutic context of ACTB

• Reverse transcriptase polymerase chain reaction (RT-PCR) and Northern blot analyses quantitated with reference to ACTB expression levels verified the trends in gene expression levels observed by array analysis for 14/15 and 8/8 genes, respectively [43].
• Quantitative reverse transcription polymerase chain reaction (QRT-PCR) was performed to quantitate endothelial nitric oxide synthase (eNOS) and beta-actin mRNA levels [44].
• Actin cytoskeleton was visualized with fluorescence microscopy application and microfilaments rhodamine-conjugated phalloidin staining. beta-actin subcellular localization was done by immunofluorescence staining with monoclonal anti-beta actin antibodies [2].
• We synthesized the associated ISC beta-actin tryptic cystine-peptide (KCF-CDVDIR), characterized it by HPLC, MS. and MSMS, and identified it in the tryptic digest of the ISC beta-actin [45].
• Immunofluorescence and immunohistochemistry using differentiation, proliferation, and adhesion markers showed that DGC initiation seems to occur at the proliferative zone (the upper neck) of the gastric epithelium and correlates with absent or reduced expression of junctional proteins (beta-actin, p120, Lin-7) [46].

References