Expression of an equine herpesvirus 1 ICP22/ICP27 hybrid protein encoded by defective interfering particles associated with persistent infection
Expression of an equine herpesvirus 1 ICP22/ICP27 hybrid protein encoded by defective interfering particles associated with persistent infection
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DOI：
10.1128/jvi.70.1.313-320.1996
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发表时间：
1996-01-01
影响因子：
5.4
通讯作者：
OCallaghan, DJ
中科院分区：
文献类型：
--
作者：
Chen, M;Harty, RN;OCallaghan, DJ
马疱疹病毒1型（EHV-1）的缺陷性干扰（DI）颗粒能够介导持续感染（S。A.道恩豪尔河A.罗宾逊和D. J. O'Callaghan，J. Gen，Virol，60：1-14，1982; R. A.罗宾逊河B。万斯和D. J. O'Callaghan，J. Virol，36：204-219，1980），克隆的DI颗粒DNA的序列分析揭示了两个调节基因ICP 22（IR 4）和ICP 27（UL 3）的部分在读框中连接以形成独特的杂合开放阅读框（ORF）。该杂合ORF，命名为IR 4/UL 3基因，编码IR 4蛋白的氨基末端196个氨基酸（ICP 22同源物）和UL 3蛋白的羧基末端68个氨基酸编码这两种调节蛋白的DNA序列的部分，在标准病毒基因组中相隔超过115 kbp，推测通过两个相同的8-bp序列之间的同源重组事件连接，逆转录酶-PCR和S1核酸酶分析显示，在DI颗粒富集的感染中，该独特的ORF是通过利用ICP 22的转录起始位点和ICP 27的多聚腺苷酸化信号转录的，免疫沉淀和Western blot用ICP 22和ICP 27蛋白的抗血清进行的免疫印迹分析表明，在DI颗粒中合成了31-kDa的杂合蛋白。这种31-kDa的杂合蛋白在DI颗粒富集感染中与ICP 22蛋白同时表达，并在聚丙烯酰胺凝胶电泳上迁移到与从克隆的IR 4/UL 3表达载体表达的蛋白相同的位置，这些观察结果表明，独特的IR 4/UL 3杂合基因从DI颗粒基因组中表达，并可能在DI颗粒介导的持续感染中发挥作用。
Defective interfering (DI) particles of equine herpesvirus type 1 (EHV-1) are capable of mediating persistent infection (S. A. Dauenhauer, R. A. Robinson, and D. J. O'Callaghan, J. Gen, Virol, 60:1-14, 1982; R. A. Robinson, R. B. Vance, and D. J. O'Callaghan, J. Virol, 36:204-219, 1980), Sequence analysis of cloned DI particle DNA revealed that portions of two regulatory genes, ICP22 (IR4) and ICP27 (UL3), are linked in frame to form a unique hybrid open reading frame (ORF), This hybrid ORF, designated as the IR4/UL3 gene, encodes the amino-terminal 196 amino acids of the IR4 protein (ICP22 homolog) and the carboxy-terminal 68 amino acids of the UL3 protein (ICP27 homolog), Portions of DNA sequences encoding these two regulatory proteins, separated by more than 115 kbp in the standard virus genome, were linked presumably by a homologous recombination event between two identical 8-bp sequences, Reverse transcriptase-PCR and S1 nuclease analyses revealed that this unique ORF is transcribed by utilizing the transcription initiation site of ICP22 and the polyadenylation signal of ICP27 in DI particle enriched infection, Immunoprecipitation and Western blot (immunoblot) analyses with antisera to the ICP22 and ICP27 proteins demonstrated that a 31-kDa hybrid protein was synthesized in the DI particle-enriched infection but not in standard virus infection, This 31-kDa hybrid protein was expressed at the same time as the ICP22 protein in DI particle-enriched infection and migrated at the same location on polyacrylamide gel electrophoresis as the protein expressed from a cloned IR4/UL3 expression vector, These observations suggested that the unique IR4/UL3 hybrid gene is expressed from the DI particle genome and may play a role in DI particle-mediated persistent infection.