Disease relevance of EXOSC2

• In addition, the specificity of HH16 is improved in the presence of p7 nucleocapsid protein from human immunodeficiency virus (HIV)-1, which accelerates the association and dissociation of RNA helices [1].
• The p7 polypeptide of hepatitis C virus is critical for infectivity and contains functionally important genotype-specific sequences [2].
• Functional analyses of GB virus B p13 protein: development of a recombinant GB virus B hepatitis virus with a p7 protein [3].
• Mutations that reduce RNA packaging efficiency have been localized to the highly basic nucleocapsid (NC) p7 domain of Pr55Gag, but the importance of the basic amino acid residues in specific viral RNA encapsidation and infectivity has not been thoroughly investigated in vivo [4].
• Analysis of E. coli/X. oryzae RNAP hybrids locates the p7 binding site to the largest X. oryzae RNAP subunit, beta'. Binding of p7 to X. oryzae RNAP holoenzyme prevents large conformational change that places the sigma subunit region 4 into the correct position for interaction with the -35 promoter element [5].

High impact information on EXOSC2

• Recombinant Rrp4p, Rrp44p, and Rrp41p are 3'-->5' exoribonucleases in vitro that have distributive, processive, and phosphorolytic activities, respectively [6].
• We demonstrate that the homolog of the Rrp4p exosome subunit is also a component of the PM-Scl complex, thereby providing compelling evidence that the yeast exosome and human PM-Scl complexes are functionally equivalent [7].
• We conclude that the 7S pre-rRNA is processed to 5.8S rRNA by a 3'-->5' exonuclease activity involving Rrp4p [8].
• Immunoprecipitated Rrp4p exhibited a 3'-->5' exoribonuclease activity in vitro that required RNA with a 3'-terminal hydroxyl group and released nucleoside 5' monophosphates [8].
• The RRP4 gene was cloned by complementation of the ts growth phenotype of rrp4-1 strains [8].

Chemical compound and disease context of EXOSC2

• The p7 protein of hepatitis C virus forms an ion channel that is blocked by the antiviral drug, Amantadine [9].

Biological context of EXOSC2

• A chimera in which the p7 of the 1a clone was replaced with p7 from an infectious genotype 2a clone also was not viable [2].
• Because HCV does not replicate efficiently in cell culture, we mutagenized p7 of an infectious genotype 1a cDNA clone and tested RNA transcripts of each mutant for infectivity in chimpanzees by intrahepatic transfection [2].
• METHODS: By means of multiple sequence alignment and molecular modeling, we searched for structural similarities among pollen allergens with 2 (Phl p 7, timothy grass; Aln g 4, alder), 3 (Bet v 3, birch) and 4 EF hands (Jun o 4, prickly juniper) [10].
• Finally, we note that some mutations affect virus replication more drastically than RNA incorporation, providing in vivo evidence for the hypothesis that NC p7 may be involved in aspects of the HIV life cycle in addition to RNA packaging [4].
• The intrinsic spectroscopic probe used in these studies is the photoexcited triplet state of Trp37, which is associated with the C-terminal zinc finger of p7 and is its only tryptophan residue [11].

Anatomical context of EXOSC2

• Previous studies indicate that this protein is an integral membrane protein, which is targeted to the membrane of the endoplasmic reticulum (ER) by the signal sequence located in its preceding p7 protein [12].
• These and HIS-tagged p7 function as calcium ion channels in black lipid membranes [9].
• The p7/p23 protein complex of bovine neutrophils can therefore be considered as a positive regulator of NADPH oxidase activation in neutrophils [13].
• AIM: To investigate the biological function of p7 protein and to look for proteins interacting with p7 protein in hepatocytes [14].

Associations of EXOSC2 with chemical compounds

• A hierarchy of IgE cross-reactivity (rPhl p7 > rAln g 4 > rJun o 4 > rBet v 3) could be established that identified rPhl p 7 as the EF-hand allergen containing most IgE epitopes in the population studied [10].

Other interactions of EXOSC2

• The hRrp4p and hRrp42p components were most frequently targeted [15].
• In addition, the results of co-immunoprecipitation assays indicate that at least two copies of hRrp4p and hRrp41p are associated with a single exosome, suggesting that at least two of these ring structures are present in this complex [16].

Analytical, diagnostic and therapeutic context of EXOSC2

• IgE cross-reactivity among the allergen families was studied with purified rPhl p 7, rAln g 4, rBet v 3, and rJun o 4 and 2 synthetic peptides comprising the N-terminal and C-terminal EF hands of Phl p 7 by means of ELISA competition [10].

References