BIOL 300 Discussion 10: RNA Processing

mRNA Processing

Modification of mRNA after transcription.

Spliceosome

Complex that excises introns from pre-mRNA.

snRNA

Small nuclear RNA involved in splicing.

snRNP

Small nuclear ribonucleoproteins aiding in splicing. (snRNA + protein)

Alternative Splicing

Different mRNA forms from a single pre-mRNA.

Capping

Addition of a 5' cap to mRNA.

Polyadenylation

Addition of a poly(A) tail to mRNA.

Guanylyl Transferase

Enzyme adding 5' cap to RNA.

CPSF

Recognizes AAUAAA for polyadenylation.

CstF

Recruits endonucleases for RNA cleavage.

CFI and CFII

Cleavage factors that cut RNA.

PAP

Synthesizes poly(A) tail at 3' end.

PABP

Binds poly(A) tail for mRNA stability.

mRNA Stability

Duration mRNA remains intact for translation.

RNA Degradation

Process of mRNA breakdown in cells.

Exosome

Complex degrading RNA in eukaryotes.

Gene Silencing

Regulation of gene expression via RNAi.

miRNAs

Small RNAs that inhibit gene expression.

Polysome

Multiple ribosomes translating one mRNA.

3' UTR

Untranslated region affecting mRNA stability.

Deadenylation-dependent Decapping

Eukaryote Degradation: Process removing the cap from mRNA.

RNA Silencing

Mechanism of gene expression regulation.

mRNA is degraded by ______

Degradosome

Direction of RNA Digestion in Eukaryotes

5' to 3'

CPSF Name

Cleavage and polyadenlytion factor

CstF Name

Cleavage stimulatory factor

CFI and CFII Name

Cleavage Factor I and II

PAP Name

Poly(A) Polymerase

PABP Name

Poly(A) Binding protein