A novel overlapping gene azyx-1 affects the translation of zyxin in C. elegans

Overlapping genes are widely prevalent, however, their expression and consequences are poorly understood. Here, we describe and functionally characterize a novel zyx-1 overlapping gene, azyx-1, with distinct regulatory functions in C. elegans. We observed conservation of alternative open reading frames overlapping the 5 region of zyxin family members in several animal species, and find shared sites of azyx-1 and zyxin proteoform expression in C. elegans. In line with a standard ribosome scanning model, our results support cis regulation of zyx-1 long isoform(s) by upstream initiating azyx-1a. Moreover, we report on a rare observation of trans regulation of zyx-1 by azyx-1, with evidence of increased ZYX-1 upon azyx-1 overexpression. Our results suggest a dual role for azyx-1 in influencing zyx-1 proteoform heterogeneity and highlights its impact on C. elegans muscular integrity and locomotion.