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any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk and legumes; "a diet high in protein"
any of a group of viruses including those that in humans cause upper respiratory infections or infectious pinkeye
the 5th letter of the Roman alphabet (同)e

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2017/07/12 15:27:04」(JST)

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Adenovirus E1B protein usually refers to one of two proteins transcribed from the E1B gene of the adenovirus: a 55kDa protein and a 19kDa protein. These two proteins are needed to block apoptosis in adenovirus-infected cells. E1B proteins work to prevent apoptosis that is induced by the small adenovirus E1A protein, which stabilizes p53, a tumor suppressor.^[1]^[2]

Functions

E1B-19k

E1B-19k blocks a p53-independent apoptosis mechanism. Without E1B-19k, degradation of both cellular and viral DNA occurs, in addition to premature host cell death during the lytic cycle, thus limiting viral replication.^[3] E1B-19k mimics MCL1, which is a cellular antiapoptotic protein.^[4] In infected cells, the expression of E1A results in the degradation of MCL-1, which normally binds the propaptotic protein, BAK.^[4] BAK activation induces apoptosis by cooligomerizing with another proapoptotic protein, BAX. Together, BAK and BAX form pores in the mitochondrial membrane, releasing apoptogenic proteins like cytochrome c.^[3]^[5] This and other proteins released from the mitochondria lead to activation of caspase-9 and caspase-3 and the resulting apoptotic program.^[6] However, in adenovirus-infected cells, activated BAK and BAX are sequestered by E1B-19k, preventing the pathway.^[3]

E1B-55k

E1B-55k blocks p53 from inhibiting cell cycling and stops it from inducing apoptosis.^[7] Observations show that E1b-55k inhibits activation by p53 by binding a repression domain to it, converting it from an activator to a repressor of p53-activated genes. This stabilizes p53 and causes a large increase in p53 concentration. Additionally, p53 bound to E1B-55k has an affinity for its binding site that is ten times higher than free p53.^[8] Presumably, this increased affinity and concentration of p53 turns the p53-E1B-55k complex into a powerful repressor.^[9]

E1B-55k also forms a complex with E4orf6, a viral protein.^[10] The E1B-55k/E4orf6 complex in infected cells assembles with other cellular proteins to form a ubiquitin ligase complex.^[11] Essentially, the E1B-55k/E4orf6 complex takes over the cellular ubiquitin ligase complexes and gives them viral substrate-recognition subunits.^[9] There are two known substrates for this ubiquitin ligases; p53 and the MRN complex.^[11]^[12] The MRN complex, if not bound by the E1B-55K/E4orf6 ubiquitin ligase, will treat the ends of the viral DNA like a double-stranded DNA break and the viral DNA becomes ligated into long concatomers of randomly assorted genomes.^[13]

References

^ Lowe, SW; Ruley, HE (1993). "Stabilization of the p53 tumor suppressor is induced by adenovirus 5 E1A and accompanies apoptosis". Genes & Development. 7: 535–545. doi:10.1101/gad.7.4.535.
^ White, E; Cipriani, R (January 10, 1990). "Role of adenovirus E1B proteins in transformation: altered organization of intermediate filaments in transformed cells that express the 19-kilodalton protein.". Molecular Cell Biology. 10 (1): 120–130. doi:10.1128/MCB.10.1.120.
^ ^a ^b ^c White, Eileen (2001). "Regulation of the cell cycle and apoptosis by the oncogenes of adenovirus". Oncogene. 20 (54): 7836–7846. doi:10.1038/sj.onc.1204861.
^ ^a ^b Cuconati, Andrea; Chandreyee, Mukherjee; Perez, Denise; White, Eileen (2003). "DNA damage response and MCL-1 destruction initiate apoptosis in adenovirus-infected cells". Genes & Development. 17: 2922–2932. PMC 289151 . PMID 14633975. doi:10.1101/gad.1156903.
^ White, E; Cuconati, A (2002). "Viral homologs of BCL-2: role of apoptosis in the regulation of virus infection". Genes & Development. 16 (19): 2465–2478. doi:10.1101/gad.1012702.
^ Cory, Suzanne; Huang, David; Adams, Jerry (2003). "The Bcl-2 family: roles in cell survival and oncogenesis". Oncogene. 22: 8590–8607. doi:10.1038/sj.onc.1207102.
^ Debbas, M; White, E (April 1993). "Wild-type p53 mediates apoptosis by E1A, which is inhibited by E1B". Genes & Development. 7 (4): 546–554. doi:10.1101/gad.7.4.546.
^ Martin, ME; Berk, AJ (1998). "Adenovirus E1B 55k represses p53 activation in vitro". Journal of Virology. 72 (4): 3146–3154. PMC 109770 . PMID 9525640.
^ ^a ^b Berk, Arnold (2005). "Recent lessons in gene expression, cell cycle control, and cell biology from adenovirus". Oncogene. 24: 7673–7685. PMID 16299528. doi:10.1038/sj.onc.1209040.
^ Sarnow, P; Hearing, P; Anderson, CW; Halbert, DN; Shenk, T; Levine, AJ (1984). "Adenovirus early region 1B 58,000-dalton tumor antigen is physically associated with an early region 4 25,000-dalton protein in productively infected cells". Journal of Virology. 49 (3): 692–700. PMC 255526 . PMID 6699935.
^ ^a ^b Querido, Emmanuelle; Blanchette, Paola; Yan, Qin; Kamura, Takumi; Morrison, Megan; Boivin, Dominique; Kaelin, William; Conaway, Ronald; Conaway, Joan; Branton, Philip (2001). "Degradation of p53 by adenovirus E4orf6 and E1B55k proteins occurs via a novel mechanism involving a Cullin-containing complex". Genes & Development. 15: 3104–3117. PMC 312842 . PMID 11731475. doi:10.1101/gad.926401.
^ Stracker, Travis; Carson, Christian; Weitzman, Matthew (2002). "Adenovirus oncoproteins inactivate the Mre11-RAd50-NBS1 DNA repair complex". Nature. 418: 348–352. doi:10.1038/nature00863.
^ Weiden, MD; Ginsberg, HS (1994). "Deletion of the E4 region of the genome produces adenovirus concatemers". PNAS. 91 (1): 153–157. PMC 42904 . PMID 8278357. doi:10.1073/pnas.91.1.153.

UpToDate Contents

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1. Epidemiology and clinical manifestations of adenovirus infection
2. アデノウイルス感染の診断、治療、および予防 diagnosis treatment and prevention of adenovirus infection
3. アデノウイルスの病因およびベクター使用 adenovirus pathogenesis and vector applications
4. 成人におけるウイルス性胃腸炎の疫学および病因 epidemiology and pathogenesis of viral gastroenteritis in adults
5. 小児および思春期における急性感染性咽頭炎の診断へのアプローチ approach to diagnosis of acute infectious pharyngitis in children and adolescents

English Journal

Markers of autophagy are adapted to hyperglycaemia in skeletal muscle in type 2 diabetes.

Kruse R1, Vind BF, Petersson SJ, Kristensen JM, Højlund K.
Diabetologia.Diabetologia.2015 Jun 7. [Epub ahead of print]
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PMID 26048236

Autophagy and apoptosis in liver injury.

Wang K1.
Cell cycle (Georgetown, Tex.).Cell Cycle.2015 Jun 3;14(11):1631-42. doi: 10.1080/15384101.2015.1038685.
Apoptosis is a primary characteristic in the pathogenesis of liver disease. Hepatic apoptosis is regulated by autophagic activity. However, mechanisms mediating their interaction remain to be determined. Basal level of autophagy ensures the physiological turnover of old and damaged organelles. Autop
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Janmohamed SR1,2, Brinkhuizen T3, den Hollander JC4, Madern GC2, de Laat PC5, van Steensel MA3, Oranje AP6.
Clinical and experimental dermatology.Clin Exp Dermatol.2015 Jun;40(4):431-7. doi: 10.1111/ced.12557. Epub 2014 Dec 16.
BACKGROUND: The pathogenesis of infantile haemangioma (IH) is unknown. Several mechanisms have been proposed, including hypoxia, which triggers upregulation and stabilization of hypoxia-inducible factor (HIF)1α. HIF1α stimulates downstream transcription of target genes that enhance angiogenesis.AI
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Japanese Journal

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Hirayama Naho,Aki Toshihiko,Funakoshi Takeshi,Noritake Kanako,Unuma Kana,Uemura Koichi
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… <p>BNIP3 (BCL2/adenovirus E1B nineteen kilodalton interacting protein-3), a member of the BCL2 family, is activated under hypoxic conditions and induces apoptosis or mitochondrial autophagy for adapting cells to hypoxia. … In order to understand the role of BNIP3 in the bovine ovary, we examined its mRNA and protein expressions of BNIP3 in follicular granulosa cells and corpus luteum (CL). …
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Kuroda Shinji,Urata Yasuo,Fujiwara Toshiyoshi
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NAID 120004040523