The herpesvirus saimiri ORF73 gene product interacts with host-cell mitotic chromosomes and self-associates via its C terminus.
The herpesvirus saimiri (HVS) ORF73 gene product shares limited homology with the ORF73 protein of Kaposi's sarcoma-associated herpesvirus (KSHV). ORF73 is expressed in an in vitro model of HVS latency, where the genome persists as a non-integrated circular episome. This suggests it may have a similar role to KSHV ORF73 in episomal maintenance, by tethering viral genomes to host-cell chromosomes. Here, the association of ORF73 with host mitotic chromosomes is described. Deletion analysis demonstrates that the distal 123 aa of the ORF73 protein are required for mitotic chromosomal localization and for self-association. Moreover, deletion of the extreme C terminus disrupts both self-association and host mitotic chromosome colocalization. This suggests that HVS ORF73 has a similar role to KSHV ORF73 in episomal maintenance and that association of ORF73 to host mitotic chromosomes is dependent on its ability to form multimers.
Calderwood
Michael A
MA
School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
Hall
Kersten T
KT
Institute of Cardiovascular Research, University of Leeds, Leeds LS2 9JT, UK.
Matthews
David A
DA
Department of Pathology and Microbiology, University of Bristol, Bristol BS8 1TD, UK.
Whitehouse
Adrian
A
School of Biochemistry and Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral; D019556:COS Cells; D002522:Chlorocebus aethiops; D002875:Chromosomes / Q000378:metabolism* / Q000502:physiology; D019281:Dimerization; D017353:Gene Deletion; D006567:Herpesvirus 2, Saimiriine / Q000378:metabolism*; D008938:Mitosis; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017354:Point Mutation; D014162:Transfection
D000956:Antigens, Viral; D009687:Nuclear Proteins; C109540:latency-associated nuclear antigen