Details

Autor(en) / Beteiligte

• Brewster, Connie D
• Birkenheuer, Claire H
• Vogt, Megan B
• Quackenbush, Sandra L
• Rovnak, Joel

Titel

The retroviral cyclin of walleye dermal sarcoma virus binds cyclin-dependent kinases 3 and 8

Ist Teil von

• Virology (New York, N.Y.), 2011-01, Vol.409 (2), p.299-307

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2011

Quelle

MEDLINE

Beschreibungen/Notizen

• Abstract Walleye dermal sarcoma virus encodes a retroviral cyclin (rv-cyclin) with a cyclin box fold and transcription activation domain (AD). Co-immune precipitation (co-IP) identified an association of rv-cyclin with cyclin-dependent kinase 8 (cdk8). Cdk8 is dependent upon cyclin C and regulates transcription with the Mediator complex, a co-activator of transcription. Mutation of cyclin residues, required for cdk binding, disrupts rv-cyclin–cdk8 co-IP. Mutation or removal of the AD has no effect on cdk8 interaction. Direct rv-cyclin–cdk8 binding is demonstrated by pulldown of active cdk8 and by GST-rv-cyclin binding to recombinant cdk8. Cdk3 is also activated by cyclin C and phosphorylates retinoblastoma protein to initiate entry into the cell division cycle. Co-IP and pulldowns demonstrate direct rv-cyclin binding to cdk3 as well. The rv-cyclin functions as a structural ortholog of cyclin C in spite of its limited amino acid sequence identity with C cyclins or with any known cyclins.