What is alternative polyadenylation?

What is alternative polyadenylation?

Alternative polyadenylation (APA) is an important post-transcriptional regulatory mechanism that processes RNA products depending on its 3′-untranslated region (3′-UTR) specific sequence signal.

Where does alternative polyadenylation occur?

Alternative polyadenylation (APA), a phenomenon that RNA molecules with different 3′ ends originate from distinct polyadenylation sites of a single gene, is emerging as a mechanism widely used to regulate gene expression.

Are MicroRNAs polyadenylated?

Human microRNAs are processed from capped, polyadenylated transcripts that can also function as mRNAs. RNA. 2004 Dec;10(12):1957-66.

What role do MicroRNAs play in post-transcriptional regulation?

MicroRNA (miRNA) is a small non-coding RNA with an established function to regulate genes at the post-transcriptional level leading to suppression or degradation of its messenger RNA expression (mRNA). Its dysregulation plays a vital role in a variety of biological and pathological processes including cancer.

What are alternative promoters?

Alternative promoter: an alternative region from which transcripts of a gene originate. The existence of multiple transcripts for a single gene that differ in their 50 termini reflects the presence of alternative promoters.

What do microRNAs do?

microRNA is the name of a family of molecules that helps cells control the kinds and amounts of proteins they make. That is, cells use microRNA to help control gene expression. Molecules of microRNA are found in cells and in the bloodstream.

How are microRNAs produced?

MicroRNAs are transcribed by RNA polymerases II and III, generating precursors that undergo a series of cleavage events to form mature microRNA. The conventional biogenesis pathway consists of two cleavage events, one nuclear and one cytoplasmic.

What is bidirectional promoter?

A bidirectional promoter is the intergenic region between two divergent genes located on complementary strands of the DNA which drives their coordinated transcription in opposite directions.

What is the process of polyadenylation?

Then an enzyme called poly-A polymerase adds a chain of adenine nucleotides to the RNA. This process, called polyadenylation, adds a poly-A tail that is between 100 and 250 residues long. The poly-A tail makes the RNA molecule more stable and prevents its degradation.

What is alternative splicing and why is it important?

Alternative splicing is a molecular mechanism that modifies pre-mRNA constructs prior to translation. This process can produce a diversity of mRNAs from a single gene by arranging coding sequences (exons) from recently spliced RNA transcripts into different combinations.

What is the role of microRNAs in the eukaryotic cell?

MicroRNAs (miRNAs) are short RNA molecules which bind to target mRNAs, resulting in translational repression and gene silencing and are found in all eukaryotic cells.

Is CMV promoter bidirectional?

The interference, involving the human cytomegalovirus-immediate-early promoter and human elongation-factor-1alpha promoter, occurred bidirectionally with both promoters markedly impairing expression of the adjacent transcription unit.

What is bidirectional transcription?

In this review, they define bidirectional transcription as: Transcription that occurs on both the positive and negative strands of DNA simultaneously, where the direction of RNA polymerase progression along each strand is either is convergent or divergent.