Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/09/24 13:40:49」(JST)

wiki en

In molecular biology and genetics, transactivation is increased rate of gene expression triggered either by biological processes or by artificial means, through expressing an intermediate (transactivator) protein.

Natural transactivation

Transactivation can be triggered either by endogenous cellular or viral proteins, so-called transactivators. These protein factors act in trans (i.e., intermolecularly). HIV and HTLV are just two of the many viruses that encode transactivators to enhance their own gene expression. These transactivators can also be associated with cancer if they start interacting and increasing expression of a cellular proto-oncogene. HTLV for instance has been associated with causing leukemia primarily through this process. Its transactivator (named tax) can interact with p40, causing overexpression of interleukin 2, interleukin receptors, GM-CSF and the transcription factor c-Fos. HTLV infects T-cells and so, with increased expression of these stimulatory cytokines and transcription factors, leads to uncontrolled proliferation of T-cells and hence lymphoma.

Artificial transactivation

Artificial transactivation of a gene is achieved by inserting into the genome at the appropriate area a transactivator gene and special promoter regions of DNA. The transactivator gene expresses a transcription factor that binds to specific promoter region of DNA. By binding to the promoter region of a gene, the transcription factor causes that gene to be expressed. The expression of one transactivator gene can activate multiple genes, as long as they have the specific promoter region attached. Because the expression of the transactivator gene can be controlled, transactivation can be used to turn genes on and off. If this specific promoter region is also attached to a reporter gene, we can see when the transactivator is being expressed.

External links

Transactivation at the US National Library of Medicine Medical Subject Headings (MeSH)
Transactivators at the US National Library of Medicine Medical Subject Headings (MeSH)

This molecular or cell biology article is a stub. You can help Wikipedia by expanding it.

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

1. B型肝炎ウイルスの特性および感染の病因 characteristics of the hepatitis b virus and pathogenesis of infection
2. 自己免疫性副腎不全の病因 pathogenesis of autoimmune adrenal insufficiency
3. HIV感染患者における心血管疾患の病因およびバイオマーカー pathogenesis and biomarkers of cardiovascular disease in hiv infected patients
4. ヒト免疫不全ウイルス（HIV）関連肺動脈性高血圧症 pulmonary arterial hypertension associated with human immunodeficiency virus
5. ヒトヘルペスウイルス7感染 human herpesvirus 7 infection

English Journal

Magnesium ion leachables induce a conversion of contractile vascular smooth muscle cells to an inflammatory phenotype.

Zhou Y, Liu X, Huang N, Chen Y.
Journal of biomedical materials research. Part B, Applied biomaterials. 2019 May;107(4)988-1001.
Phenotype switching is a characteristic response of vascular smooth muscle cells (vSMCs) to the dynamic microenvironment and contributes to all stages of atherosclerotic plaque. Here, we immersed pure magnesium and AZ31 alloy in the completed medium under cell culture condition, applied the resultan
PMID 30270501

Hepatitis B virus X reduces hepatocyte apoptosis and promotes cell cycle progression through the Akt/mTOR pathway in vivo.

Wang X, Huo B, Liu J, Huang X, Zhang S, Feng T.
Gene. 2019 Apr;691()87-95.
Hepatitis B virus X (HBx), a viral onco-protein encoded by HBV, can promote oncogenesis of HCC. However, the mechanism of HBx in hepatocarcinogenesis is still unclear. In this study, we establish a new mouse model with normal immune system to investigate the role of HBx and its functional mechanisms
PMID 30630095

HIV-1 Tat enhances purinergic P2Y4 receptor signaling to mediate inflammatory cytokine production and neuronal damage via PI3K/Akt and ERK MAPK pathways.

Zhou F, Liu X, Gao L, Zhou X, Cao Q, Niu L, Wang J, Zuo D, Li X, Yang Y, Hu M, Yu Y, Tang R, Lee BH, Choi BW, Wang Y, Izumiya Y, Xue M, Zheng K, Gao D.
Journal of neuroinflammation. 2019 Apr;16(1)71.
HIV-associated neurocognitive disorders (HANDs) afflict more than half of HIV-1-positive individuals. The transactivator of transcription (Tat) produced by HIV virus elicits inflammatory process and is a major neurotoxic mediator that induce neuron damage during HAND pathogenesis. Activated astrocyt
PMID 30947729

Japanese Journal

Downregulating immunogenicity of Schwann cells via inhibiting a potential target of class II transactivator (CIITA) gene

Yang Yi,Dai Wenda,Chen Zhengrong,Yan Zuoqin,Yao Zhenjun,Zhang Chi
BioScience Trends 7(1), 50-55, 2013
… Class II transactivator (CIITA) gene is a chief regulator of major histocompatibility complex class II (MHC II) molecules which contributes to the immunogenicity of Schwann cells. …
NAID 130004572585

歯周病原細菌による潜伏感染EBVの再活性化と病態への関与

今井健一,落合邦康
無菌生物 = Japanese journal of germfree life and gnotobiology 42(2), 91-96, 2012-12-01
NAID 10031131378

Heat-inducible transgene expression system incorporating a positive feedback loop of transcriptional amplification for hyperthermia-induced gene therapy(MEDICAL BIOTECHNOLOGY)

Yamaguchi Masaki,Ito Akira,Okamoto Noriaki [他],Kawabe Yoshinori,Kamihira Masamichi
Journal of bioscience and bioengineering 114(4), 460-465, 2012-10
… The target gene expression mediated by the transactivator under the control of a heat shock protein 70B' promoter is enhanced by self-promoted transactivator gene expression. …
NAID 110009543735