from Part II - Basic virology and viral gene effects on host cell functions: alphaherpesviruses
Published online by Cambridge University Press: 24 December 2009
Initiation of transcription and RNA synthesis
The alphaherpesviruses, HSV -1 and VZV encode TATA -box containing promoters that are transcribed by the cellular RNA polymerase II
During productive infection by herpes simplex virus type 1 (HSV-1), approximately 80 genes encoded within the linear 152-kbp viral genome are expressed in three sequential phases that are termed immediate early (IE; α), early (E; β) and late (L; γ)(Honess and Roizman, 1974; McGeoch, 1991). The smaller, 125-kbp varicella zoster virus (VZV) genome encodes around 70 genes, which are also expressed as IE, E and L products (Davison and Scott, 1986). HSV -1 and VZV genes are transcribed by the cellular RNA Polymerase II and each viral promoter has a TATA box homology about 25 nucleotides upstream of the start site of transcription (for review, see Wagner et al., 1995). In HSV -1infections, the first genes to be transcribed are the five IE genes, which are distinguished from E and L genes by specific sequence elements termed TAATGARAT sequences in the upstream regions of IE promoters. These elements are recognized by a virion tegument protein, VP 16, which binds as part of a protein complex that contains two cellular factors, Oct-1 and HCF, to transcriptionally activate expression of IE genes (Wysocka and Herr, 2003). VZV IE genes do not appear to encode upstream promoter elements similar to the TAATGARAT sequence, however VZV does encode a protein, ORF 10 that exhibits similarities with VP 16, although its activity has been much less well characterized than that of VP 16 (Piette et al., 1995).
To save this book to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.
To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.