TY - JOUR
T1 - Thermostability/Infectivity Defect Caused by Deletion of the Core Protein V Gene in Human Adenovirus Type 5 Is Rescued by Thermo-selectable Mutations in the Core Protein X Precursor
AU - Ugai, Hideyo
AU - Borovjagin, Anton V.
AU - Le, Long P.
AU - Wang, Minghui
AU - Curiel, David T.
N1 - Funding Information:
We thank Drs Joel N. Glasgow, Igor P. Dmitriev, Masato Yamamoto and Angel A. Rivera for useful advice and fruitful discussions. We are grateful to Dr Igor P. Dmitriev for providing a rabbit polyclonal pIX-specific antibody, Dr D. A. Matthews for providing a rabbit polyclonal pV-specific antibody, and Drs Gene P. Siegel, Justin Roth Qiana L Matthews and Anand C. Annan for critical reading of the manuscript. We gratefully thank Dr Lacey McNally for technical support. This work was supported by grants from the National Institutes of Health (RO1CA111569 and T32CA075930).
PY - 2007/3/2
Y1 - 2007/3/2
N2 - Mastadenoviruses represent one of the four major genera of the Adenoviridae family comprising a variety of mammalian pathogens including human adenovirus (Ad), whose genomes encode a gene for minor core protein V (pV), not found in other genera of Adenoviridae. Deletion of other genus-specific genes (gene IX and E3 genes) from the Ad type 5 (Ad5) genome has been studied experimentally in vitro and the results on biological characterization of the mutants support the phylogenetic evidence of those genes being non-essential for Ad viability. On this basis it seemed logical to suggest that a deletion of gene V from the Ad5 genome could also be tolerated. To test this hypothesis we constructed and rescued the first pV-deletion mutant of human Ad5. As compared to Ad5, this mutant formed small plaques, had dramatically reduced thermostability and lower infectivity. A subsequent thermoselection screen of the pV-deleted Ad5 allowed isolation of a suppressor mutant Ad5-dV/TSB with restored biological characteristics. Since replication and viral assembly of Ad5-dV/TSB could still occur in the absence of pV, we conclude that pV is a non-essential component of the virion. The observed rescue of the biological defects appears to be associated with a cluster of point mutations in the gene encoding the precursor for the other core protein, X/Mu. This finding, thus, suggests possible roles of pV and protein X/Mu precursor in viral assembly. It also provides an interesting insight into genetic events that mediate molecular adaptation of viruses to possible changes in the genetic background in the course of their evolutionary divergence. The possible mechanism of the observed genetic suppression is discussed.
AB - Mastadenoviruses represent one of the four major genera of the Adenoviridae family comprising a variety of mammalian pathogens including human adenovirus (Ad), whose genomes encode a gene for minor core protein V (pV), not found in other genera of Adenoviridae. Deletion of other genus-specific genes (gene IX and E3 genes) from the Ad type 5 (Ad5) genome has been studied experimentally in vitro and the results on biological characterization of the mutants support the phylogenetic evidence of those genes being non-essential for Ad viability. On this basis it seemed logical to suggest that a deletion of gene V from the Ad5 genome could also be tolerated. To test this hypothesis we constructed and rescued the first pV-deletion mutant of human Ad5. As compared to Ad5, this mutant formed small plaques, had dramatically reduced thermostability and lower infectivity. A subsequent thermoselection screen of the pV-deleted Ad5 allowed isolation of a suppressor mutant Ad5-dV/TSB with restored biological characteristics. Since replication and viral assembly of Ad5-dV/TSB could still occur in the absence of pV, we conclude that pV is a non-essential component of the virion. The observed rescue of the biological defects appears to be associated with a cluster of point mutations in the gene encoding the precursor for the other core protein, X/Mu. This finding, thus, suggests possible roles of pV and protein X/Mu precursor in viral assembly. It also provides an interesting insight into genetic events that mediate molecular adaptation of viruses to possible changes in the genetic background in the course of their evolutionary divergence. The possible mechanism of the observed genetic suppression is discussed.
KW - Mastadenovirus
KW - adenovirus
KW - core proteins
KW - pV deletion
KW - thermoselection
UR - http://www.scopus.com/inward/record.url?scp=33846847657&partnerID=8YFLogxK
U2 - 10.1016/j.jmb.2006.11.090
DO - 10.1016/j.jmb.2006.11.090
M3 - Article
C2 - 17208253
AN - SCOPUS:33846847657
SN - 0022-2836
VL - 366
SP - 1142
EP - 1160
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
IS - 4
ER -