Co-option of an ancestral peptidase controls developmental patterning in multicellular cyanobacteria.

ABSTRACT: Spatial patterning in multicellular organisms is commonly explained by Turing-type reaction-diffusion systems, but the maturation of diffusible inhibitors remains poorly understood. In the cyanobacterium Nostoc PCC 7120, nitrogen deprivation triggers a pattern of nitrogen-fixing heterocysts regulated by HetR and inhibitory peptides, including PatX. We uncover the post-translational mechanism controlling PatX maturation, demonstrating its export and subsequent processing by the peptidase PatP. We identify HRGTGR, a PatX-derived hexapeptide, as the direct inhibitor of HetR, linking maturation to suppressed differentiation. Genomic analyses reveal that patP is ancient and conserved across all cyanobacteria, predating the patX-hetR module found only in filamentous clades.

SUBMITTER: Xu X 

PROVIDER: S-EPMC12756182 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature