early viral transcription

Definition

Target type: biologicalprocess

The first phase of viral transcription that occurs after entry of the virus into the host cell, but prior to viral genome replication. It involves the transcription of genes for non-structural proteins, and for lytic viruses, the early gene products are involved in establishing control over the host cell. [GOC:bf, GOC:jh2, GOC:jl]

Early viral transcription is the initial stage of gene expression in the viral life cycle, marking the first step in the hijacking of the host cell's machinery for viral replication. This intricate process begins with the entry of the viral genome into the host cell, followed by the initiation of transcription by the host RNA polymerase. The key to this process lies in the viral genome's ability to manipulate the host's transcription machinery.

For DNA viruses, the initial step often involves the synthesis of early viral proteins, which play crucial roles in regulating viral gene expression and replicating the viral genome. These proteins can act as transcription factors, binding to specific DNA sequences within the viral genome and directing the transcription of later genes.

RNA viruses, on the other hand, directly utilize their RNA genome as a template for transcription. This is facilitated by the presence of viral enzymes within the virion, such as RNA-dependent RNA polymerases, which are capable of synthesizing new RNA strands from an RNA template.

The specific mechanisms of early viral transcription differ greatly between viral families, but some general principles apply. Firstly, the viral genome often contains specific sequences that serve as promoters, attracting host RNA polymerase and initiating transcription. Secondly, many viruses encode regulatory proteins that bind to the viral genome, modulating the efficiency of transcription and ensuring the production of the necessary viral proteins at the appropriate time.

The outcome of early viral transcription is the production of a set of viral mRNA molecules that encode essential viral proteins, including proteins that are involved in viral replication, assembly, and spread. These proteins are then translated into functional proteins, marking the transition into the next stage of the viral life cycle.'
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Proteins (1)

Compounds (1)