RNA regulation
● The Degradation of RNA
○ 5′-cap removal
○ Shortening of the poly(A) tail
○ Degradation of 5′ UTR, coding sequence, and 3′ UTR
Some genes code for regulating RNA called microRNA
● Regulation of gene expression by microRNAs (miRNAs)
○ Double stranded rna
○ miRNA binds to dicer protein in cytoplasm
○ If bases are complementary, one of the strands of RNA is degraded/silenced using
RISC binding
■ If match is less complete, translation is blocked
■ RNA can silence genes (RNA inducing silencing complex)
■ Leads to siRNA (small interfering RNA)
■ dsRNA → siRNA
● Using RNAi (RNA interference) for treatment of human disease- silencing of gene
expression
○ RNAi can be used to reduce levels of transthyretin and amyloid for patients with
transthyretin amyloidosis
○ RNAi can be used to reduce levels of ApoB and blood cholesterol
■ ApoB carries cholesterol in the blood
● High levels of cholesterol can lead to heart disease
● Sources of dsRNAs (double stranded rna):
○ Transcription of both strands of genomic sequence (miRNA gene)
○ Arise from exogenous virus
○ From researchers (we create small interfering siRNA)
● RISC degrades one of the strands of RNA and it is left with one strand of RNA that
serves as the guide and looks for complementary mRNA to bind
○ If it complementary, it is cleaved and degraded
○ If it is not completely complementary, binds to RNA and inhibits translation
● miRNA - translation inhibition; siRNA - RNA cleavage
● Converting RNA transcripts to cDNA
○ Release mRNAs from cytoplasm and purify
○ Add oligo-dT primers and treat with reverse transcriptase
RNAi (rna interference) and siRNA (small interfering rna)
● RNA interference happens when a cell doesn’t want to turn all of the mRNA that it
creates into protein or it wants to attack RNA made by attacking virus
● Dicer: chops up long, double stranded RNA molecules (Into siRNA)
○ These short fragments are RNA are picked up by RISC (RNA silencing complex),
which is composed of a slicer protein
● The Degradation of RNA
○ 5′-cap removal
○ Shortening of the poly(A) tail
○ Degradation of 5′ UTR, coding sequence, and 3′ UTR
Some genes code for regulating RNA called microRNA
● Regulation of gene expression by microRNAs (miRNAs)
○ Double stranded rna
○ miRNA binds to dicer protein in cytoplasm
○ If bases are complementary, one of the strands of RNA is degraded/silenced using
RISC binding
■ If match is less complete, translation is blocked
■ RNA can silence genes (RNA inducing silencing complex)
■ Leads to siRNA (small interfering RNA)
■ dsRNA → siRNA
● Using RNAi (RNA interference) for treatment of human disease- silencing of gene
expression
○ RNAi can be used to reduce levels of transthyretin and amyloid for patients with
transthyretin amyloidosis
○ RNAi can be used to reduce levels of ApoB and blood cholesterol
■ ApoB carries cholesterol in the blood
● High levels of cholesterol can lead to heart disease
● Sources of dsRNAs (double stranded rna):
○ Transcription of both strands of genomic sequence (miRNA gene)
○ Arise from exogenous virus
○ From researchers (we create small interfering siRNA)
● RISC degrades one of the strands of RNA and it is left with one strand of RNA that
serves as the guide and looks for complementary mRNA to bind
○ If it complementary, it is cleaved and degraded
○ If it is not completely complementary, binds to RNA and inhibits translation
● miRNA - translation inhibition; siRNA - RNA cleavage
● Converting RNA transcripts to cDNA
○ Release mRNAs from cytoplasm and purify
○ Add oligo-dT primers and treat with reverse transcriptase
RNAi (rna interference) and siRNA (small interfering rna)
● RNA interference happens when a cell doesn’t want to turn all of the mRNA that it
creates into protein or it wants to attack RNA made by attacking virus
● Dicer: chops up long, double stranded RNA molecules (Into siRNA)
○ These short fragments are RNA are picked up by RISC (RNA silencing complex),
which is composed of a slicer protein
