Heterogeneity of subgenomic mRNAs of a mutant mouse hepatitis virus strain JHM2C.
Heterogeneity of subgenomic mRNAs of a mutant mouse hepatitis virus strain JHM2C.
复制标题
突变小鼠肝炎病毒株 JHM2C 亚基因组 mRNA 的异质性。
DOI：
10.1007/978-1-4615-1325-4_79
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发表时间：
2001
影响因子：
--
通讯作者：
Zhang,X
中科院分区：
文献类型：
--
作者：
Zhang,X
Mouse hepatitis virus (MHV), a prototype of murine Coronavirus, contains a single-strand, positive-sense RNA genome of ≈32 kb in length (Lee et al, 1991; Pachuk et al. 1989). Upon viral infection into susceptible cells, the viral genomic RNA serves both as an mRNA for translation of the RNA-dependent RNA Polymerase polyprotein, which is required for subsequent RNA transcription and replication and as a template for the synthesis of the negative-strand RNA (Lai and Cavanagh, 1997). The genome-length, negative-strand RNA, in turn, is used for the synthesis of the viral genome. Six to seven subgenomic mRNAs (mRNAs 2 to 7) are found in MHV-infected cells; they are co-nested at the 3′-ends. Each mRNA contains a leader sequence of approximately 70 nucleotides (nt) at the 5’-end, which is identical to the leader of the genomic RNA. Depending on MHV strains, there are two to four consensus UCUAA repeats with the last repeat being UCUAAAC, at the 3’-end of the leader. An identical or similar consensus sequence is present between each gene, termed intergenic (IG) sequence, which serves as a transcription initiation signal (promoter) for subgenomic mRNA synthesis (based on the leader-primed transcription model) or a termination signal for subgenomic negative-strand RNA synthesis (based on the discontinuous transcription on the negative-strand RNA) (Lai and Cavanagh, 1997, and ref. therein). Regardless of which transcription model Coronavirus actually utilizes, the IG is thecis-acting sequence absolutely required for subgenomic RNA transcription; it serves as a joining point between the leader (or antileader) and the remaining body part of each subgenomic RNA. This structural feature lead to propose that Coronavirus RNA transcription results from RNA-RNA base-pairing between the consensus sequences of the leader and the IG template.
