TY - JOUR
T1 - Replication of lengthened Moloney murine leukemia virus genomes is impaired at multiple stages
AU - Shin, Nam Hee
AU - Hartigan-O'Connor, Dennis
AU - Pfeiffer, Julie K.
AU - Telesnitsky, Alice
PY - 2000
Y1 - 2000
N2 - It has been assumed that RNA packaging constraints limit the size of retroviral genomes. This notion of a retroviral 'headful' was tested by examining the ability of Moloney murine leukemia virus genomes lengthened by 4, 8, or 11 kb to participate in a single replication cycle. Overall, replication of these lengthened genomes was 5- to 10-fold less efficient than that of native-length genomes. When RNA expression and virion formation, RNA packaging, and early stages of replication were compared, long genomes were found to complete each step less efficiently than did normal-length genomes. To test whether short RNAs might facilitate the packaging of lengthy RNAs by heterodimerization, some experiments involved coexpression of a short packageable RNA. However, enhancement of neither long vector RNA packaging nor long vector DNA synthesis was observed in the presence of the short RNA. Most of the proviruses templated by 12 and 16 kb vectors appeared to be full length. Most products of a 19.2-kb vector contained deletions, but some integrated proviruses were around twice the native genome length. These results demonstrate that lengthy retroviral genomes can be packaged and that genome length is not strictly limited at any individual replication step. These observations also suggest that the lengthy read-through RNAs postulated to be intermediates in retroviral transduction can be packaged directly without further processing.
AB - It has been assumed that RNA packaging constraints limit the size of retroviral genomes. This notion of a retroviral 'headful' was tested by examining the ability of Moloney murine leukemia virus genomes lengthened by 4, 8, or 11 kb to participate in a single replication cycle. Overall, replication of these lengthened genomes was 5- to 10-fold less efficient than that of native-length genomes. When RNA expression and virion formation, RNA packaging, and early stages of replication were compared, long genomes were found to complete each step less efficiently than did normal-length genomes. To test whether short RNAs might facilitate the packaging of lengthy RNAs by heterodimerization, some experiments involved coexpression of a short packageable RNA. However, enhancement of neither long vector RNA packaging nor long vector DNA synthesis was observed in the presence of the short RNA. Most of the proviruses templated by 12 and 16 kb vectors appeared to be full length. Most products of a 19.2-kb vector contained deletions, but some integrated proviruses were around twice the native genome length. These results demonstrate that lengthy retroviral genomes can be packaged and that genome length is not strictly limited at any individual replication step. These observations also suggest that the lengthy read-through RNAs postulated to be intermediates in retroviral transduction can be packaged directly without further processing.
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U2 - 10.1128/JVI.74.6.2694-2702.2000
DO - 10.1128/JVI.74.6.2694-2702.2000
M3 - Article
C2 - 10684285
AN - SCOPUS:0034049619
SN - 0022-538X
VL - 74
SP - 2694
EP - 2702
JO - Journal of virology
JF - Journal of virology
IS - 6
ER -