Regulation of Gene Expression Flashcards
What is the function of the polyA tail?
Confers stability to the mRNA transcript
What is the pattern of transcription of heterochromatin?
It is less expressed and tightly wound
How does miRNA differ from siRNA in its mechanism of action?
miRNAs aren’t completely complementary with their mRNA targets
What is the pattern of methylation and acetylation of heterochromatin?
Hypermethylated DNA
Low acetylated histones
Variable methylation of histones
What is the pattern of methylation and acetylation of euchromatin?
Low methylation of DNA
High acetylation of histones
Variable methylation of histones
What is the common feature of promoter regions?
TATA boxes
What is the target DNA sequence for methylation?
CpG
What is the function of the spliceosome?
Cuts out introns
What is the name of the protein required for siRNA?
RISC - RNA-induced silencing complex
Where is heterochromatin generally located in the nucleus?
Close to the nuclear membrane
How does siRNA target mRNA for cleavage?
Its sequence is complementary to the sequence of mRNA which it will cleave
What is an example of post-transcriptional regulation of gene expression?
Alternative splicing exons
What is the ratio of genes to mRNA transcripts to proteins?
21,000 : 100,000 : >1,000,000
What percentage of the genome is transcribed?
80%
What are the three types of non-coding RNAs that regulate gene transcription?
Long non-coding RNAs (lncRNAs)
Short interfering RNAs (siRNAs)
Micro RNAs (miRNAs)
