The WL3 Wingless localisation element 3 (WLE3) is an
RNA
Ribonucleic acid (RNA) is a polymeric molecule essential in various biological roles in coding, decoding, regulation and expression of genes. RNA and deoxyribonucleic acid ( DNA) are nucleic acids. Along with lipids, proteins, and carbohydra ...
structure
A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ...
that localises the
wingless
The Wnt signaling pathways are a group of signal transduction pathways which begin with proteins that pass signals into a cell through cell surface receptors. The name Wnt is a portmanteau created from the names Wingless and Int-1. Wnt signaling p ...
mRNA
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of Protein biosynthesis, synthesizing a protein.
mRNA is ...
in flies.
The structure consists of a stem, a bulge region, another stem and a loop.
The published structure was determined and refined through experiments.
Wingless localisation element 3 (WLE3) is a 53-
nt (nt 518–570) apical localization
element within the
3'-untranslated region
In molecular genetics, the three prime untranslated region (3′-UTR) is the section of messenger RNA (mRNA) that immediately follows the translation termination codon. The 3′-UTR often contains regulatory regions that post-transcriptionally ...
of the
wingless
The Wnt signaling pathways are a group of signal transduction pathways which begin with proteins that pass signals into a cell through cell surface receptors. The name Wnt is a portmanteau created from the names Wingless and Int-1. Wnt signaling p ...
(wg) mRNA. It is shown to be sufficient and necessary for apical RNA transport in microinjection assays and transgenic reporters.
Indeed,
deletion of WLE3 in an otherwise full-length wg 3'UTR completely abolishes apical localization. However, a minimal WLE3 monomer by itself shows weak activity on its own. The incomplete activity of
a single WLE3 element indicates a requirement for additional elements or sequences.
Phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
comparison of WLE3 elements predicts a highly conserved
stem-loop
Stem-loop intramolecular base pairing is a pattern that can occur in single-stranded RNA. The structure is also known as a hairpin or hairpin loop. It occurs when two regions of the same strand, usually complementary in nucleotide sequence when ...
structure in
''
Drosophila
''Drosophila'' () is a genus of flies, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or (less frequently) pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species ...
'' species (using ALIFOLD) and deemed necessary for WLE function by mutational analyses.
Full WLE3 activity is dependent on appropriate downstream sequences and can also be blocked by
downstream sequences. Targeted
mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mi ...
s on the sequence and structural aspects of WLE3 stem-loop
were done and tested showing the distal stem to be most important, the central variable region
while must be present its sequences and bulges appear to be unimportant and the WLE3 loop with
two invariant
residues is not required for localization.
References
External links
*
Transterm page for WLE3 Element
{{DEFAULTSORT:Wingless Localisation Element 3 (Wle3)
Cis-regulatory RNA elements