Virion-associated protein kinases.

Many purified virions, particularly enveloped virus particles (such as retrovirus, hepadnavirus, herpesvirus, orthomyxovirus, and paramyxovirus), contain protein kinase (PK) activity. This type of PK has been called virion-associated protein kinase (VAPK). Even though some VAPKs are identified either as a cellular PK or viral-encoded kinase, many remain to be identified. Although the roles of VAPKs are not yet well characterized, there is ample evidence to suggest their importance in viral infectivity, uncoating, transcription, and replication.