Disease relevance of SNORA73A

• Replication of all these plasmids was absolutely dependent on the presence of the HPV-18 E1 and E2 proteins [1].
• Soluble extracts from uninfected murine cells supplemented with purified viral E1 and E2 proteins support the replication of exogenously added papilloma virus DNA [2].
• Previous studies defining the viral genes affecting HPV-16 transformation functions have used the "prototype" viral genome, which was cloned from a human cervical carcinoma and later discovered to harbor a mutation in the E1 gene [3].
• The HPV-11 E2 protein appears not to be essential for elongation, but it must be present in the preinitiation complex for the E1 protein to recruit host DNA replication machinery to the ori [4].
• The replication of the human papillomavirus type 11 (HPV-11) origin was achieved by using human 293 cell extracts supplemented with the HPV-11 E1 and E2 proteins purified from insect cells infected with recombinant baculoviruses [5].

High impact information on SNORA73A

• Second generation E1 deleted viruses further crippled by a temperature sensitive mutation in the E2a gene were associated with substantially longer recombinant gene expression and less inflammation [6].
• We have also revised the nucleotide sequence of the E1b region of Ad5 [7].
• The E2 transactivator stimulates the binding of the E1 replication protein to the minimal origin of replication and activates DNA replication [2].
• The structure and associated mutational analyses reveal molecular details of Ubc12 recruitment by NEDD8's E1 [8].
• Structural basis for recruitment of Ubc12 by an E2 binding domain in NEDD8's E1 [8].

Chemical compound and disease context of SNORA73A

• The maturation of rubella virus (RV) glycoproteins E2 and E1 was examined by using brefeldin A (BFA) and monensin [9].
• A murine monoclonal antibody directed against the E1 membrane glycoprotein of rubella virus was immobilized on an N-hydroxysuccinimide-activated chromatographic support [10].
• Adeno-P450, a replication-defective, E1/E3 region-deleted adenovirus engineered to express CYP2B6-IRES-P450R, induced intracellular CPA 4-hydroxylation, and CPA cytotoxicity, in a broad range of human cancer cell lines [11].
• These signals include transactivation by: adenovirus E1a/E1b proteins; activated p21ras; and in CHO cells, treatment with the DNA damaging agent MNNG [12].
• To address this problem, we developed an E1b 55 kDa attenuated, replication-competent adenovirus (Ad.TKRC) which expresses the herpes simplex-1 thymidine kinase (HSVtk) gene to sensitize tumors to ganciclovir (GCV) [13].

Biological context of SNORA73A

• Binding of E1 to the origin was increased by E2 proteins and required the presence of E2 binding sites [14].
• To examine the interplay of these replication proteins, we have analyzed the binding of human papillomavirus (HPV) type 31b E1 and E2 proteins to the origin of replication [14].
• These observations suggest a model whereby modulation of the relative levels of E1 and E2 during the viral life cycle may alter the pattern of origin binding and possibly episomal copy number [14].
• mRNA splicing regulates human papillomavirus type 11 E1 protein production and DNA replication [15].
• The origins of DNA replication in bovine and human papillomavirus genomes have been localized to a specific part of the upstream regulatory region (URR) which includes recognition sites for E1 and E2 proteins [16].

Anatomical context of SNORA73A

• The present article describes specific psoralen photocross-linking in whole HeLa cells of E1, E2, and E3 RNAs to nucleolar pre-rRNA [17].
• To address the mechanisms by which the viral DNA is stably propagated in the transformed cells, we have constructed a cell line CH04.15 expressing constitutively the viral proteins E1 and E2, that are required for initiation of viral DNA replication [18].
• In this study, we have corrected this mutation and have evaluated the effect of mutations of either the E1 or the E2 gene on the efficiency of HPV-16 immortalization of human keratinocytes [3].
• Injection of the human E1, E2, and E3 genes into Xenopus oocytes generated sequence-specific transcripts of the approximate sizes of the respective snoRNAs [19].
• The human E1 alpha and the previously isolated human E2 cDNAs were used as probes in Northern blot analysis with cultured fibroblasts and lymphoblasts from seven unrelated MSUD patients [20].

Associations of SNORA73A with chemical compounds

• Sequence components adjacent to the E1 and E2 binding sites, comprising AT-rich and purine-rich elements and the consensus TATA box sequence, probably contribute to the overall efficiency of replication, though they are nonessential [16].
• An E1 gene mutant at threonine 102 encodes for a protein which is no longer a substrate for the p34cdc2 kinase [21].
• This additional guanine shifted the reading frame and erased an interruption in the E1 gene described by Seedorf et al [22].
• The monovalent ionophore monensin, which inhibits intracellular transport of proteins through the ER-Golgi complex, was used to block the transport of E1 and E2 glycoproteins through the Golgi complex [9].
• The E1 protein of HPV-33 purified by affinity chromatography using glutathione S-transferase as tag displayed specific DNA-binding activity in footprint analyses protecting HPV-33 nucleotides 7896 to 7909/1 to 18 from DNasel digestion [23].

Physical interactions of SNORA73A

• The mechanism by which these proteins are recruited to the origin and the role of the E1/E2 complex in replication remain undefined [14].
• E1 also bound in vitro to H1 isolated under native conditions in association with intact nucleosomes [24].
• The transcription factor YY1 has been shown to regulate RNA transcription by binding to a sequence overlapping the putative E1 protein binding site in the HPV-18 ori [25].

Regulatory relationships of SNORA73A

• Binding of the human papillomavirus E1 origin-recognition protein is regulated through complex formation with the E2 enhancer-binding protein [14].
• We also found that E2 but not E1 protein expressed in mammalian cells is bound tightly to GRP78 [26].

Other interactions of SNORA73A

• Therefore, changes in the relative amounts of E1 and E2 proteins can dramatically alter the pattern of binding of viral replication factors to the origin [14].
• The E1 gene is located within the first intron of the gene for RCC1, a protein that regulates onset of mitosis [19].
• Production and characterization of improved adenovirus vectors with the E1, E2b, and E3 genes deleted [27].
• Bound H1 was displaced from HPV-11 DNA by the addition of E1, suggesting that E1 can promote replication initiation and elongation by alteration of viral chromatin structure and disruption of nucleosomes at the replication fork [24].

Analytical, diagnostic and therapeutic context of SNORA73A

• Levels and functional affinities of IgG specific for individual RV proteins (E1, E2, and C) were measured by enzyme immunoassay (EIA) [28].
• Isothermal titration calorimetry and changes in protein fluorescence showed that the inhibitors bind to the transactivation domain of E2, the region that interacts with E1 [29].
• Histone H1 was identified as an HPV type 11 (HPV-11) E1-binding protein by far-Western blotting and by microsequence analyses of a 34-kDa protein purified by E1 affinity chromatography [24].
• Sequence alignments and secondary-structure prediction for HPV-16 E1 and other superfamily 3 (SF3) viral helicases closely parallel the mapping data in suggesting that aa 439 to 623 constitute a discrete helicase domain [30].
• The viral copy number/cell was assessed by dot-blot hybridization and the presence of E1/E2 genes by PCR and Southern blot [31].

References