GRE Subject Test: Biochemistry, Cell, and Molecular Biology › Help with Developmental Proteins
How do master regulators, which are transcription factors, establish cell subtypes and cell subtype-specific gene expression?
Master regulators promote the deposition of methyl or acetyl groups to mark inactive or active enhancers
Master regulators always promote formation of euchromatin in nucleosome dense regions
Master regulators promote active promoter formation by deposition of methyl groups
None of the other answers
Master regulators bind promoters by not enhancers to initiate specific gene expression
The correct answer is master regulators promote the deposition of methyl or acetyl groups to mark inactive or active enhancers. Master regulators bind enhancer regions that have been created by pioneer factors to establish the chromatin state of the cell by deposition of methyl or acetyl groups on chromatin. Methylation correlates with inactive enhancers, whereas acetylation correlates with active enhancers. The fingerprint of active/inactive enhancers and its effect on gene expression establishes cell subtypes. Some, but not all master regulators function as pioneer factors to bind nucleosome rich DNA to promote euchromatin formation.