The CaMV 35S promoter
Analysis on the CaMV 35 promoter is divided into a discussion of:
- the promoter itself
- sequences identified in patents as “35S enhancer regions”
- the “minimal” promoter
The promoter itself
At the beginning of the 1980s, Chua and collaborators at the Rockefeller University isolated the promoter responsible for the transcription of the whole genome of a Cauliflower mosaic virus (CaMV) infecting turnips. The promoter was named CaMV 35S promoter (“35S promoter”) because the coefficient of sedimentation of the viral transcript whose expression is naturally driven by this promoter is 35S. It is one of the most widely used, general-purpose constitutive promoters.
The 35S promoter is a very strong constitutive promoter, causing high levels of gene expression in dicot plants. However, it is less effective in monocots, especially in cereals. The differences in behavior are probably due to differences in quality and/or quantity of regulatory factors.
The promoter responsible for the transcription of another part of the genome of CaMV, the CaMV 19S promoter, is also used as a constitutive promoter, but is not as widely used as the 35S promoter.