Characterization of an RNP Complex That Assembles on the Rous Sarcoma Virus Negative Regulator of Splicing Element

Only a fraction of retroviral primary transcripts are spliced to subgenomic mRNAs; the unspliced transcripts are transported to the cytoplasm for packaging into virions and for translation of the gag and pol genes. We identified cis-acting sequences within the gag gene of Rous sarcoma virus (RSV) which negatively regulate splicing in vivo. Mutations were generated downstream of the splice donor (base 397) in the intron of a proviral clone of RSV. Deletion of bases 708 to 800 or 874 to 987 resulted in a large increase in the level of spliced RSV RNA relative to unspliced RSV RNA. This negative regulator of splicing (nrs) also inhibited splicing of a heterologous splice donor and acceptor pair when inserted into the intron. The nrs element did not affect the level of spliced RNA by increasing the rate of transport of the unspliced RNA to the cytoplasm but interfered more directly with splicing. To investigate the possible role of gag proteins in splicing, we studied constructs carrying frameshift mutations in the gag gene. While these mutations, which caused premature termination of gag translation, did not affect the level of spliced RSV RNA, they resulted in a large decrease in the accumulation of unspliced RNA in the cytoplasm.

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Localization and Characterization of the src-gene Product of Rous Sarcoma Virus

Cold Spring Harbor Symposia on Quantitative Biology ◽

10.1101/sqb.1980.044.01.107 ◽

1980 ◽

Vol 44 (0) ◽

pp. 991-1005 ◽

Cited By ~ 3

Author(s):

A. R. Goldberg ◽

J. G. Krueger ◽

E. Wang

Keyword(s):

Gene Product ◽

Rous Sarcoma Virus ◽

Rous Sarcoma ◽

Src Gene ◽

Sarcoma Virus

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Regulation of Rous sarcoma virus RNA splicing and stability.

Molecular and Cellular Biology ◽

10.1128/mcb.8.11.4858 ◽

1988 ◽

Vol 8 (11) ◽

pp. 4858-4867 ◽

Cited By ~ 66

Author(s):

S Arrigo ◽

K Beemon

Keyword(s):

Rous Sarcoma Virus ◽

Rna Splicing ◽

Negative Regulator ◽

Splice Donor ◽

Acceptor Pair ◽

Cis Acting ◽

Rous Sarcoma ◽

Donor And Acceptor ◽

Sarcoma Virus

Only a fraction of retroviral primary transcripts are spliced to subgenomic mRNAs; the unspliced transcripts are transported to the cytoplasm for packaging into virions and for translation of the gag and pol genes. We identified cis-acting sequences within the gag gene of Rous sarcoma virus (RSV) which negatively regulate splicing in vivo. Mutations were generated downstream of the splice donor (base 397) in the intron of a proviral clone of RSV. Deletion of bases 708 to 800 or 874 to 987 resulted in a large increase in the level of spliced RSV RNA relative to unspliced RSV RNA. This negative regulator of splicing (nrs) also inhibited splicing of a heterologous splice donor and acceptor pair when inserted into the intron. The nrs element did not affect the level of spliced RNA by increasing the rate of transport of the unspliced RNA to the cytoplasm but interfered more directly with splicing. To investigate the possible role of gag proteins in splicing, we studied constructs carrying frameshift mutations in the gag gene. While these mutations, which caused premature termination of gag translation, did not affect the level of spliced RSV RNA, they resulted in a large decrease in the accumulation of unspliced RNA in the cytoplasm.

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