Calmodulin‐related CML 24 interacts with ATG 4b and affects autophagy progression in A rabidopsis

Summary Plants encounter environmental stress challenges that are distinct from those of other eukaryotes because of their relative immobility. Therefore, plants may have evolved distinct regulatory mechanisms for conserved cellular functions. Plants, like other eukaryotes, share aspects of both calcium‐ and calmodulin‐based cellular signaling and the autophagic process of cellular renewal. Here, we report a novel function for an A rabidopsis calmodulin‐related protein, CML 24, and insight into ATG 4‐regulated autophagy. CML 24 interacts with ATG 4b in yeast two‐hybrid, in vitro pull‐down and transient tobacco cell transformation assays. Mutants with missense mutations in CML 24 have aberrant ATG 4 activity patterns in in vitro extract assays, altered ATG 8 accumulation levels, an altered pattern of GFP – ATG 8‐decorated cellular structures, and altered recovery from darkness‐induced starvation. Together, these results support the conclusion that CML 24 affects autophagy progression through interactions with ATG 4.