 |
Selective Factor 1
Selective factor 1 (also known as SL1) is a transcription factor that binds to the promoter of genes and recruits a preinitiation complex to which RNA polymerase I will bind to and begin the transcription of ribosomal RNA (rRNA). Discovery SL1 was discovered by Robert Tjian and his colleagues in 1985 when they separated a HeLa cell extract into two functional fractions. One factor has RNA polymerase I activity, but no ability to initiate accurate transcription of a human rRNA template. This transcription factor, SL1, showed species specificity. That is, it could distinguish between the human and mouse rRNA promoter, and added increasing amount of human template at the expense of the mice template. Tijian and coworkers went on to show that by footprinting a partially purified polymerase 1 preparation could bind to the human rRNA promoter. In particular it causes a footprint over a region of the UCE called ''A site''. This binding is not due to polymerase I itself but to a tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
|
Role Of Transcription Factor In Gene Expression Regulation
A role (also rôle or social role) is a set of connected behaviors, rights, obligations, beliefs, and norms as conceptualized by people in a social situation. It is an expected or free or continuously changing behavior and may have a given individual social status or social position. It is vital to both functionalist and interactionist understandings of society. Social role theory posits the following about social behavior: # The division of labour in society takes the form of the interaction among heterogeneous specialized positions, we call roles. # Social roles included appropriate and permitted forms of behavior and actions that recur in a group, guided by social norms, which are commonly known and hence determine the expectations for appropriate behavior in these roles, which further explains the position of a person in the society. # Roles are occupied by individuals, who are called actors. #When individuals approve of a social role (i.e., they consider the role legitim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |