%0 Journal Article
%A Moreno-Rodríguez, Antonio
%A Mier Muñoz, Pablo
%A Pérez-Pulido, Antonio J.
%T Evolutionary perspective of the CAG/CAA interplay coding for pure polyglutamine stretches in proteins
%D 2025
%U https://hdl.handle.net/10433/23949
%X Polyglutamine regions appear in many eukaryotic proteins. Most research on these stretches has focused on humans and primates. We wantedto check whether patterns in their codon usage are shared across a wide taxonomic range. Protein-coding transcripts from 30 eukaryotic modelspecies were searched for stretches of consecutive glutamine codons (CAA/CAG). Most species have higher CAG proportion in longer stretches,except fishes, which either reduced or kept a stable CAG use. CAA codons are located closer to the C-terminal side of the stretches in plants,invertebrates, and tetrapods; fungi showed no bias and fishes showed the opposite. Many tetrapods have codons flanking pure CAG stretchesthat hint at a mutational control of repeat growth. However, the maximum number of consecutive identical codons within the polyglutaminestretches in most species followed random expectations, with fishes as a main exception. We detected shared patterns in codon usage andposition across taxonomically distant species, yet each group retained unique traits. Internal CAA position and external flanking codons bothseemed to slow pure CAG expansion. Overall, a mix of random processes and species-specific factors drives how glutamine repeats are shapedand maintained in evolution.
%K Polyglutamina
%K Proteínas
%~