Proteolysis in plants articles from across Nature Portfolio

Chromosomal patterning of meiotic crossovers is mediated by pro-crossover HEI10 E3 ligase dynamics. This study reveals that a network of HSP40–HSP70 chaperones facilitates HEI10 proteolysis, thereby limiting formation of closely spaced crossovers.

Ubiquitination triggers endocytosis of proteins from the plasma membrane. The TASH3 subunit of the TPLATE complex recognizes ubiquitinated proteins via its SH3 domain-containing appendage and initiates their internalization from the plasma membrane.

Fruit ripening is a fine-tuned process involving wholesale changes to both the structure and metabolism of the fruit. Now, the CHLORAD proteolytic pathway is shown to regulate chromoplast development, thus altering the ripening process of tomato fruits.

During stomatal opening and closing, the guard cell microtubule cytoskeleton is reorganised. Here the authors show that the E3 ubiquitin ligase MREL57 targets the microtubule stabilizing protein WDL7 to promote microtubule disassembly during ABA-induced stomatal closure.

NOT4 proteins associate with ribosomes and are required for co-translational quality control in yeast and animals. Here, Bailey et al. show that Arabidopsis NOT4A positively regulates the expression of the nuclear encoded pentatricopeptide repeat (PPR) protein PGR3 and is required for ribosome biogenesis and mRNA translation in the chloroplast.

Most chloroplast proteins are imported from the cytosol and thus transiently exposed to the cytosolic proteasome. Here the authors show that impairment of the cytosolic proteasome can elevate precursor protein abundance and photosynthetic activity suggesting that cytosolic protein turnover is a means to tune plastid function.

A new protein degradation pathway driven by late-endosome-localized MULTIDRUG AND TOXIC COMPOUND EXTRUSION (MATE) efflux transporters opposes autophagy at the onset of senescence. Paradoxically, the new pathway requires a central component of autophagy.

Cold stress activatesArabidopsis thalianaplasma membrane-localized CRPK1, which leads to 14-3-3 proteins entering the nucleus and promoting the degradation of CBF transcription factors, thus attenuating the cold-induced response.

The auxin receptor TIR1 is an F-box protein functioning in a ubiquitin ligase complex to target repressors for degradation. It is itself an unstable protein, but newly identified mutations protect both TIR1 and its substrates from degradation. These mutations could help in identifying the substrates for hundreds of other F-box proteins.