Abstract
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 Caenorhabditis elegans. We observed conservation of alternative open reading frames (ORFs) 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 highlight its impact on C. elegans muscular integrity and locomotion.