BIOL 4610: Transcriptional Regulation

mRNA can leave the nucleus through __

Nuclear pores

__ read the message carried by mRNA sequence and use that info to build proteins

Ribosomes

Genes

DNA segments that do code for proteins

Transcription

DNA sequence of the gene must be copied into an RNA sequence

__ play a role in the regulation of transcription, turning some genes on and others off

Histone modifications

Main types of RNA polymerase:

RNA Polymerase I, RNA Polymerase II, RNA Polymerase III

RNA Polymerase I transcribes __

47S pre-rRNA

RNA Polymerase II __

mRNA, snRNAs, scRNAs

RNA Polymerase III

tRNAs, 5s rRNA, snRNAs, scRNAs

General Transcription Factors (GTFs)

Help properly position RNA pol II on the template DNA when it connects to the promoter regions of a gene

Main parts of transcription factors:

• DNA binding domain that recognizes regulatory sequences for a gene

• Activation domain that recruits factors to activate or repress genes

The GTFs and RNA pol II assemble around TFIID to form the __

Promoter Initiation Complex (PIC)

Transcription factors (TFs) bind to __ of genes

Regulatory sequences

Regulatory sequences are located in the __

Linker regions between nucleosomes

TFs can be categorized into __

Activators and repressors

Activator

Helps general transcription factors and RNA pol assemble

Repressor

Blocks general transcription factors and RNA polymerase

Activators and repressors recruit __ to control nucleosome density

Chromatin remodeling enzymes

Transcription factors that are repressors often recruit __

HDACs, HMTs

Transcription factors that are activators often recruit __

HATs

DNA methylation

Methyl groups are adddd to cytosine nucleotides in the promoters of genes

DNA methylation is carried out by __

DNMT

The NMT enzyme can be recruited by repressors and __

Form complexes with HDACs and HMTs

The coorditnated action of DNMTs, HDACs, and HMTs in gene inactivation is crucial for __

Cell differentiation

Epigenetic memory

Ensures the permanent inactivation of specific genes in each cell lineage; DNA and histone methylation can be inherited in each cell division

TFIIH function

Transcription regulation and DNA repair (nucleotide excision repair)