TIC236 is an essential bridge that links the chloroplast outer and inner membrane protein translocon complexes. Here, we unveil a TIC236-allied component, the chloroplast outer membrane protein CRUMPLED LEAF (CRL), absence of which impairs plastid division and induces autoimmune responses. A forward genetic screen exploring CRL function found multiple dominant TIC236 gain-of-function (tic236-gf) mutations that abolished crl-induced phenotypes. We show that CRL interacts with the transit peptides of proteins essential in plastid division, with tic236-gf mutations reinforcing their import via increased TIC236 stability. Our data shed new light on the links between plastid protein import, plastid division, and plant stress responses. The results were published in PNAS.

Article Link: https://www.pnas.org/doi/10.1073/pnas.2123353119