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Ubiquitin facilitates a quality-control pathway that removes damaged chloroplasts.

ABSTRACT: Energy production by chloroplasts and mitochondria causes constant oxidative damage. A functioning photosynthetic cell requires quality-control mechanisms to turn over and degrade chloroplasts damaged by reactive oxygen species (ROS). Here, we generated a conditionally lethal Arabidopsis mutant that accumulated excess protoporphyrin IX in the chloroplast and produced singlet oxygen. Damaged chloroplasts were subsequently ubiquitinated and selectively degraded. A genetic screen identified the plant U-box 4 (PUB4) E3 ubiquitin ligase as being necessary for this process. pub4-6 mutants had defects in stress adaptation and longevity. Thus, we have identified a signal that leads to the targeted removal of ROS-overproducing chloroplasts.

SUBMITTER: Woodson JD

PROVIDER: S-EPMC4863637 | biostudies-literature | 2015 Oct

REPOSITORIES: biostudies-literature

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Ubiquitin facilitates a quality-control pathway that removes damaged chloroplasts.

Woodson Jesse D JD Joens Matthew S MS Sinson Andrew B AB Gilkerson Jonathan J Salomé Patrice A PA Weigel Detlef D Fitzpatrick James A JA Chory Joanne J

Science (New York, N.Y.) 20151022 6259

Energy production by chloroplasts and mitochondria causes constant oxidative damage. A functioning photosynthetic cell requires quality-control mechanisms to turn over and degrade chloroplasts damaged by reactive oxygen species (ROS). Here, we generated a conditionally lethal Arabidopsis mutant that accumulated excess protoporphyrin IX in the chloroplast and produced singlet oxygen. Damaged chloroplasts were subsequently ubiquitinated and selectively degraded. A genetic screen identified the pla ...[more]

PMID: 26494759

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