Table of Contents
What do uORFs do?
Upstream open reading frames (uORFs) are short open reading frames (ORFs) that have start codons located in the 5′ untranslated regions (UTRs) of eukaryotic mRNAs. uORFs can attenuate the translational initiation of downstream coding sequences (CDSs) by sequestering or competing for ribosomes1,2,3,4,5,6,7,8,9,10.
How does uORF participate in gene regulation?
As the new in frame stop codon produces a uORF entirely located in 5′ leader sequence, it confers the ability to reinitiate at the main ORF. This new regulation mechanism by uORF 7 produces a weaker translational repression, causing an increase of the TPO protein levels [107]–[109].
Does ORF include UTR?
ORF Predictor uses a combination of the two different ORF definitions mentioned above. It searches stretches starting with a start codon and ending at a stop codon. As an additional criterion, it searches for a stop codon in the 5′ untranslated region (UTR or NTR, nontranslated region.)
What is difference between CDS and ORF?
The Coding Sequence (CDS) is the actual region of DNA that is translated to form proteins. While the ORF may contain introns as well, the CDS refers to those nucleotides(concatenated exons) that can be divided into codons which are actually translated into amino acids by the ribosomal translation machinery.
Why are there 6 reading frames?
Every region of DNA has six possible reading frames, three in each direction. The reading frame that is used determines which amino acids will be encoded by a gene. Typically only one reading frame is used in translating a gene (in eukaryotes), and this is often the longest open reading frame.
What is the purpose of 5 UTR?
The eukaryotic 5′ untranslated region (UTR) is critical for ribosome recruitment to the mRNA and start codon choice, and plays a major role in the control of translation efficiency and shaping the cellular proteome.
Do all mRNAs have UTRs?
The mRNA is initially transcribed from the corresponding DNA sequence and then translated into protein. However, several regions of the mRNA are usually not translated into protein, including the 5′ and 3′ UTRs.
What amino acid is Gua?
Valine
| Amino acids | Symbols | Codons |
|---|---|---|
| Threonine | Thr | ACA, ACC, ACG, ACU |
| Valine | Val | GUA, GUC, GUG, GUU |
| Tryptophan | Trp | UGG |
| Tyrosine | Tyr | UAC UAU |
What are the 5 and 3 UTRs?
In molecular genetics, an untranslated region (or UTR) refers to either of two sections, one on each side of a coding sequence on a strand of mRNA. If it is found on the 5′ side, it is called the 5′ UTR (or leader sequence), or if it is found on the 3′ side, it is called the 3′ UTR (or trailer sequence).