Table of Contents
What is the function of poly-A binding protein?
Abstract. Poly (A) tails are found at the 3′ ends of almost all eukaryotic mRNAs. They are bound by two different poly (A) binding proteins, PABPC in the cytoplasm and PABPN1 in the nucleus. PABPC functions in the initiation of translation and in the regulation of mRNA decay.
What is the function of poly-A?
The poly-A tail makes the RNA molecule more stable and prevents its degradation. Additionally, the poly-A tail allows the mature messenger RNA molecule to be exported from the nucleus and translated into a protein by ribosomes in the cytoplasm.
What is the role of poly-A in mRNA stability?
The poly(A) tail functions as a ribonucleoprotein (RNP) complex with PABP, since PABP is essential to stabilize the 3′ end of an mRNA in mammalian cells (1, 17).
What is the function of the poly-A tail in eukaryotes?
Abstract. In eukaryotes, poly(A) tails usually act as stabilizers of intact mRNAs, whereas in E. coli they serve to accelerate the destruction of fragments. The mechanisms underlying these contrasting effects of the same RNA modification are discussed.
What is a poly A tract?
poly(dT) tracts (poly(A) tracts), regions of DNA containing at least 20 contiguous dA residues on one strand and dT residues on the complementary strand, are found in about 2 X 10(4) copies interspersed throughout the human genome.
Which of the following is A function of A polyA signal sequence?
Which of the following is a function of a poly-A signal sequence? It codes for a sequence in eukaryotic transcripts that signals enzymatic cleavage – 1035 nucleotides away.
What is the form and function of the mRNA poly-A tail?
The polyA tail is a long chain of adenine nucleotides that is added to a mRNA molecule during RNA processing. The polyA tail makes the RNA molecule more stable and prevents its degradation and allows the mature mRNA molecule to be exported from the nucleus and translated into a protein by ribosomes in the cytoplasm.
What is cytoplasmic poly (A) binding protein?
Discovered as early as 1973 [1], the cytoplasmic poly (A) binding protein [2], [3] is present in all eukaryotes and plays important roles in at least two processes, translation and mRNA decay.
What is polyadenylation and why is it important?
The process of polyadenylation adds a 3′ poly (A) tail and provides the mRNA with a binding site for a major class of regulatory factors, the poly (A)-binding proteins (PABPs). These highly conserved polypeptides are found only in eukaryotes; single-celled eukaryotes each have a single PABP, whereas humans have five and Arabidopis has eight.
What is poly (A)-binding protein?
Poly (A)-binding protein is also present during stages of mRNA metabolism including nonsense-mediated decay and nucleocytoplasmic trafficking. The poly (A)-binding protein may also protect the tail from degradation and regulate mRNA production.
Do poly (A) binding proteins play a role in RNA interference?
However, as binding of this receptor to its cargo depends on additional RNA binding proteins serving as ‘adaptors’, poly (A) binding proteins might play a role. So far, Nab2p is the best candidate. The protein is required not only for proper polyadenylation but also for mRNA export [181], [201].