Processing of Viral pre-mRNA

These flashcards cover key concepts related to the processing of viral pre-mRNA, including capping, polyadenylation, splicing, and regulation of gene expression.

5' Cap

A methylated guanosine added to the 5' end of the RNA transcript, which helps in recognition by the translation machinery and protects mRNA from degradation.

Poly(A) Tail

A stretch of adenosine residues added to the 3' end of mRNA, enhancing mRNA stability and translation efficiency.

Capping Enzyme

An enzyme that adds a 5' cap to the RNA transcript during transcription, ensuring that RNA Pol II transcripts are processed correctly.

Splicing

The process of removing introns from pre-mRNA and joining exons to produce a mature mRNA.

Introns

Non-coding sequences in RNA that are removed during the splicing process.

Exons

Coding sequences in RNA that remain in the mature mRNA after splicing.

Alternative Splicing

A process by which different combinations of exons are joined together to produce multiple protein variants from a single gene.

Nuclear Export

The process by which fully processed mRNAs are transported from the nucleus to the cytoplasm for translation.

RNA Editing

A molecular process that alters RNA nucleotide sequences, potentially changing the resultant protein.

RNA Interference (RNAi)

A cellular mechanism involving small interfering RNAs (siRNAs) that mediate degradation of RNA transcripts, serving as an antiviral defense.

ADAR

Adenosine deaminase that acts on RNA, an enzyme responsible for converting adenosine to inosine during RNA editing.

APOBEC

A family of enzymes involved in RNA editing that can act as a cellular antivirus defense.

Cap Snatching

A mechanism used by certain viruses to acquire a 5' cap from host cellular mRNA transcripts for their own mRNA.

HIV-1 Rev

A viral protein that binds to unspliced RNAs and facilitates their export from the nucleus to the cytoplasm.

TAP Protein

A cellular protein that binds to the constitutive transport element (CTE) in viral RNAs to aid in their nuclear export.

CPSF

Cleavage and polyadenylation specificity factor, a multisubunit factor that binds to the polyadenylation signal in mRNA for processing.

RISC

RNA-induced silencing complex, a protein complex that incorporates siRNAs and mediates the degradation of complementary RNA.

miRNA

MicroRNA, small RNA molecules processed from longer transcripts that regulate gene expression by targeting mRNA.