Nucleocapsid incorporation into parainfluenza virus is regulated by specific interaction with matrix protein
Nucleocapsid incorporation into parainfluenza virus is regulated by specific interaction with matrix protein
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DOI：
10.1128/jvi.75.3.1117-1123.2001
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发表时间：
2001-02-01
影响因子：
5.4
通讯作者：
Portner, A
中科院分区：
文献类型：
--
作者：
Coronel, EC;Takimoto, T;Portner, A
副粘病毒核蛋白(NPs)将基因组RNA封装成核衣壳，然后核衣壳被结合到病毒颗粒中。我们确定了NP分子之间的蛋白质-蛋白质相互作用，以及在两种密切相关的病毒，人类副流感病毒1型(HPIV1)和仙台病毒(SV)中将核衣壳引入病毒粒子所需的分子机制。表达的NP基因可在体内形成核衣壳。电子显微镜显示，从表达SV或hPIVI NP基因的细胞裂解物中获得的病毒核衣壳的形态没有显著差异。两种病毒的NP cDNAs共表达可形成由NP分子混合而成的核衣壳，因此，两种病毒的NP都含有可形成混合核衣壳的区域，在感染SV的细胞中也可检测到混合核衣壳。然而，当SV的NP由感染的病毒捐献时，hPIV1 NP来自于转基因的cDNA，也可以检测到由单独来自SV或单独来自hPIVI的NP组成的核衣壳。虽然两种病毒的NP在感染SV和转染人PIV1 NP基因的细胞的细胞质中几乎相同，但在子代SV病毒粒子的核衣壳中有90%的NP来自SV。因此，在子代SV病毒粒子的组装过程中，排除了含有异源hPIV1 NPs的核衣壳。在SV感染细胞中，hPIV1 NP和hPIV1基质蛋白(M)的共表达增加了含有hPIV1 NP的核衣壳的摄取；因此，M似乎负责将核衣壳特异性地掺入病毒粒子中。利用SV-hPIV1嵌合体NP cDNA，我们发现NP蛋白的C-末端结构域(氨基酸420-466)负责与M。
The paramyxovirus nucleoproteins (NPs) encapsidate the genomic RNA into nucleocapsids, which are then incorporated into virus particles. We determined the protein-protein interaction between NP molecules and the molecular mechanism required for incorporating nucleocapsids into virions in two closely related viruses, human parainfluenza virus type 1 (hPIV1) and Sendai virus (SV). Expression of NP from cDNA resulted in in vivo nucleocapsid formation. Electron micrographs showed no significant difference in the morphological appearance of viral nucleocapsids obtained from lysates of transfected cells expressing SV or hPIVI NP cDNA. Coexpression of NP cDNAs from both viruses resulted in the formation of nucleocapsid composed of a mixture of NP molecules; thus, the NPs of both viruses contained regions that allowed the formation of mixed nucleocapsid, Mixed nucleocapsids were also detected in cells infected with SV and transfected with hPIV1 NP cDNA. However, when NP of SV was donated by infected virus and hPIV1 NP was from transfected cDNA, nucleocapsids composed of NPs solely from SV or solely from hPIVI were also detected. Although almost equal amounts of NP of the two viruses were found in the cytoplasm of cells infected with SV and transfected with hPIV1 NP cDNA, 90% of the NPs in the nucleocapsids of the progeny SV virions were from SV. Thus, nucleocapsids containing heterologous hPIV1 NPs were excluded during the assembly of progeny SV virions. Coexpression of hPIV1 NP and hPIV1 matrix protein (M) in SV-infected cells increased the uptake of nucleocapsids containing hPIV1 NP; thus, M appears to be responsible for the specific incorporation of the nucleocapsid into virions. Using SV-hPIV1 chimera NP cDNAs, we found that the C-terminal domain of the NP protein (amino acids 420 to 466) is responsible for the interaction with M.