The MC4-La1 cleavage module restricts plant virus infection by integrating R-motif-mediated defense mRNA translation.

ABSTRACT: The plant cysteine protease metacaspases are structural homologs of animal caspases and play pivotal roles under biotic and abiotic stresses. However, whether metacaspases and purine-rich element (R-motif)-mediated defense messenger RNA translation are involved in plant antiviral immunity remains elusive. Here, we report that barley stripe mosaic virus (BSMV) infection activates metacaspase 4 (MC4) to cleave the RNA binding protein lupus autoantigen 1 (La1) behind residue arginine-448. The cleaved La1_1-448 version relocates to the cytoplasm and promotes the R-motif-mediated cap-independent defense mRNA translation. Moreover, MC4 overexpression restricts BSMV infection in tobacco (Nicotiana benthamiana), whereas knockout of MC4 and knockdown of La1 are more s

SUBMITTER: Pi Q 

PROVIDER: S-EPMC12459463 | biostudies-literature | 2025 Sep

REPOSITORIES: biostudies-literature