Disease relevance of Infectious Anemia Virus, Equine

• AIP1 also binds the HIV-1 p6(Gag) and EIAV p9(Gag) proteins, indicating that it can function directly in virus budding [1].
• Thus, these results demonstrate the occurrence of glycoprotein-specific structural variations during persistent infection by EIAV and support the concept of antigenic variation in this retrovirus [2].
• We now report that Sam68 also enhances the activities of Rev-like proteins of other complex retroviruses (e.g. HTLV-1 and EIAV) on their respective RNA targets [3].
• Here we show that the budding of equine infectious anemia virus (EIAV) from infected equine cells is largely unaffected by these drugs, although use of one inhibitor (MG-132) resulted in a dramatic block to proteolytic processing of Gag [4].
• Also in contrast to EIAV, the endogenous synthesis of high-molecular-weight human immunodeficiency virus type 1 DNA was drastically reduced at Nonidet P-40 concentrations above 0.02% [5].

High impact information on Infectious Anemia Virus, Equine

• AIP1/ALIX is a binding partner for HIV-1 p6 and EIAV p9 functioning in virus budding [6].
• While hCycT1 is also shown to interact with eTat, the lack of eTat function in human cells is explained by the failure of the resultant protein complex to bind to EIAV TAR [7].
• Similar to other cellular ESEs that have been identified by other laboratories, the EIAV ESE interacted specifically with SR proteins, a group of serine/arginine-rich splicing factors that function in constitutive and alternative mRNA splicing [8].
• These data suggest that EIAV Rev-induced exon skipping observed in vivo may be initiated by simultaneous binding of Rev and SR proteins to the RRE that alter the subsequent assembly or catalytic activity of the spliceosomal complex [9].
• A series of "programmed" 2-step polymerization reactions suggests that p51 EIAV RT enters an abortive mode of polymerization [10].

Chemical compound and disease context of Infectious Anemia Virus, Equine

• Finally, a reciprocal exchange of the valine for the leucine at position 29 in human and equine cyclins T1, respectively, renders the human cyclin T1 active and the equine cyclin T1 inactive for Tat transactivation from EIAV [11].
• The levels of chloramphenicol acetyltransferase activity directed by the EIAV LTRs were between 250 and 900 times greater in EIAV-infected cells compared with their uninfected counterparts [12].
• The results of these studies demonstrated that EIAV entry into all cell types was substantially inhibited in a dose-dependent manner by treatment with the vacuolar H+-ATPase inhibitors concanamycin A and bafilomycin A1 or the lysosomotropic weak base ammonium chloride [13].
• It therefore appears that the Rev protein of EIAV, while analogous in function to Rev proteins defined in lentiviruses of primate, ovine, and caprine origin, is nevertheless distinguished by an entirely novel domain organization [14].
• All nucleotide substitutions of the cytidine at position +14 increased EIAV Tat responsiveness; however, its deletion abolished trans activation [15].

Biological context of Infectious Anemia Virus, Equine

• These studies define for the first time the RNA sequence and structural determinants of Gag-Pol frameshifting necessary for EIAV replication, reveal novel aspects relative to frameshifting elements described for other retroviruses, and provide new genetic determinants that can be evaluated as potential antiviral targets [16].
• The 16 amino acid sequence of the core region is strictly conserved among the known Tat proteins, and the three-dimensional fold of these amino acids of HV1Z2 Tat protein was highly similar to the structure of the corresponding EIAV Tat domain [17].
• These findings indicate that while the promoter-proximal PU.1 site is the most critical site for EIAV LTR activity in the presence of Tat, other elements within the enhancer are needed for EIAV replication in macrophages [18].
• The p11 protein is identical to the nucleic acid-binding protein of EIAV previously isolated (C. W. Long, L. E. Henderson, and S. Oroszlan, Virology 104:491-496, 1980) [19].
• To investigate optimization of gene expression in hematopoietic cells, we compared a variety of post-transcriptional elements and promoters in the context of EIAV vectors [20].

Anatomical context of Infectious Anemia Virus, Equine

• Our results suggest that virus-encoded dUTPase is dispensable for virus replication in dividing cells in vitro but may be required for efficient replication of EIAV in nondividing equine macrophages, the natural host cells for this virus [21].
• The results of these particle budding assays revealed that expression of EIAV Gag polyprotein in COS-1 cells yielded extracellular Gag particles with a characteristic density of 1.18 g/ml, while expression of EIAV Gag polyprotein lacking p9 resulted in a severe reduction in the release of extracellular Gag particles [22].
• In HeLa cells, the product of PU.1 cDNA bound to the EIAV ets motif and activated transcription from the EIAV promoter [23].
• This study describes Th lymphocyte reactivity in EIAV carrier horses to two proteins, p26 and p15, encoded by the relatively conserved EIAV gag gene [24].
• Equine infectious anemia virus (EIAV) contains the simplest genome among lentiviruses in that it encodes only three putative regulatory genes (S1, S2, S3) in addition to the canonical gag, pol, and env genes, presumably reflecting its limited tropism to cells of monocyte/macrophage lineage [25].

Gene context of Infectious Anemia Virus, Equine

• Finally, we demonstrate that fusing EIAV Gag directly with another cellular component of the VPS machinery, VPS28, can restore efficient release of an EIAV Gag late-domain mutant [26].
• However, in contrast to HIV-1, EIAV Gag release is insensitive to TSG101 depletion and EIAV particles do not contain significant levels of TSG101 [26].
• The EIAV ets motif matches the consensus sequence for both PEA3- and PU.1-binding sites [23].
• This domain has been shown to consist of the cysteine-rich and core motifs of HIV-1 Tat and is functionally conserved in the distantly related Tat proteins of HIV-2 and EIAV [27].
• We applied isoform-specific primers in real-time RT-PCR reactions to quantitatively analyze alternative splicing in cells transfected with rev-minus EIAV provirus constructs [28].

Analytical, diagnostic and therapeutic context of Infectious Anemia Virus, Equine

• A broadly reactive competition immunoassay was developed in which antiserum to EIAV was used to precipitate 125I-labeled HTLV-III p24 [29].
• These data suggest that optimized EIAV vectors may be a suitable alternative to HIV-1 vectors for use in hematopoietic gene therapy [20].
• The viral core proteins (p15, p26, p11, and p9) of equine infectious anemia virus (EIAV) (Wyoming strain) were purified by reverse-phase high-pressure liquid chromatography [19].
• Additional evidence for the close evolutionary relationship between EIAV and a prototype lentivirus (caprine arthritis encephalitis virus) was acquired by Southern blotting and immunological analyses [30].
• Previous characterizations of equine infectious anemia virus (EIAV) glycoprotein variation by DNA sequence analysis and epitope mapping using monoclonal antibodies (MAbs) have revealed the presence of conserved and variable regions within the EIAV env gene [31].

References