Mutation of the<i>Arabidopsis</i>LON2 peroxisomal protease enhances pexophagy

Bartel, Bonnie; Farmer, Lisa M.; Rinaldi, Mauro A.; Young, Pierce G.; Danan, Charles H; Burkhart, Sarah E.

doi:10.4161/auto.27565

Cited by 24 publications

(20 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Independent evidence for pexophagy in young Arabidopsis seedlings was provided by Farmer et al . , who reported that mutations in ATG5 , ATG7 and ATG2 suppressed the LON2 protease, which, as suggested previously , is located in peroxisomes. The signal for pexophagy in plants is unknown.…”

Section: Autophagysupporting

confidence: 72%

To deliver or to degrade – an interplay of the ubiquitin–proteasome system, autophagy and vesicular transport in plants

Zientara‐Rytter

Sirko

2016

The FEBS Journal

View full text Add to dashboard Cite

The efficient utilization and subsequent reuse of cell components is a key factor in determining the proper growth and functioning of all cells under both optimum and stress conditions. The process of intracellular and intercellular recycling is especially important for the appropriate control of cellular metabolism and nutrient management in immobile organisms, such as plants. Therefore, the accurate recycling of amino acids, lipids, carbohydrates or micro-and macronutrients available in the plant cell becomes a critical factor that ensures plant survival and growth. Plant cells possess two main degradation mechanisms: a ubiquitin-proteasome system and autophagy, which, as a part of an intracellular trafficking system, is based on vesicle transport. This review summarizes knowledge of both the ubiquitin-proteasome system and autophagy pathways, describes the cross-talk between the two and discusses the relationships between autophagy and the vesicular transport systems.

show abstract

Section: Autophagysupporting

confidence: 72%

To deliver or to degrade – an interplay of the ubiquitin–proteasome system, autophagy and vesicular transport in plants

Zientara‐Rytter

Sirko

2016

The FEBS Journal

View full text Add to dashboard Cite

show abstract

“…Another possibility is suggested by the recent discovery of roles for autophagy of peroxisomes (pexophagy) and the peroxisomal protease LON2 in matrix protein degradation. Although lon2 single mutants do not stabilize ICL or MLS Burkhart et al, 2013) and although ICL and MLS are only slightly stabilized in hypocotyls when autophagy is disrupted (Kim et al, 2013b), ICL and MLS are dramatically stabilized when autophagy is disrupted in an lon2 background (Farmer et al, 2013;Bartel et al, 2014b;Goto-Yamada et al, 2014). This stabilization suggests that LON2 promotes matrix protein degradation and that peroxisomes are targeted for autophagy when LON2 is dysfunctional.…”

Section: Discussionmentioning

confidence: 80%

Peroxisomal Ubiquitin-Protein Ligases Peroxin2 and Peroxin10 Have Distinct But Synergistic Roles in Matrix Protein Import and Peroxin5 Retrotranslocation in Arabidopsis

2014

Self Cite

View full text Add to dashboard Cite

Peroxisomal matrix proteins carry peroxisomal targeting signals (PTSs), PTS1 or PTS2, and are imported into the organelle with the assistance of peroxin (PEX) proteins. From a microscopy-based screen to identify Arabidopsis (Arabidopsis thaliana) mutants defective in matrix protein degradation, we isolated unique mutations in PEX2 and PEX10, which encode ubiquitin-protein ligases anchored in the peroxisomal membrane. In yeast (Saccharomyces cerevisiae), PEX2, PEX10, and a third ligase, PEX12, ubiquitinate a peroxisome matrix protein receptor, PEX5, allowing the PEX1 and PEX6 ATP-hydrolyzing enzymes to retrotranslocate PEX5 out of the membrane after cargo delivery. We found that the pex2-1 and pex10-2 Arabidopsis mutants exhibited defects in peroxisomal physiology and matrix protein import. Moreover, the pex2-1 pex10-2 double mutant exhibited severely impaired growth and synergistic physiological defects, suggesting that PEX2 and PEX10 function cooperatively in the wild type. The pex2-1 lesion restored the unusually low PEX5 levels in the pex6-1 mutant, implicating PEX2 in PEX5 degradation when retrotranslocation is impaired. PEX5 overexpression altered pex10-2 but not pex2-1 defects, suggesting that PEX10 facilitates PEX5 retrotranslocation from the peroxisomal membrane. Although the pex2-1 pex10-2 double mutant displayed severe import defects of both PTS1 and PTS2 proteins into peroxisomes, both pex2-1 and pex10-2 single mutants exhibited clear import defects of PTS1 proteins but apparently normal PTS2 import. A similar PTS1-specific pattern was observed in the pex4-1 ubiquitin-conjugating enzyme mutant. Our results indicate that Arabidopsis PEX2 and PEX10 cooperate to support import of matrix proteins into plant peroxisomes and suggest that some PTS2 import can still occur when PEX5 retrotranslocation is slowed.

show abstract

“…A suppressor screen revealed that disabling autophagy genes in lon2 mutants results in dramatic stabilization of ICL and MLS, indicating that autophagy is involved in degrading peroxisomal proteins when LON2 is nonfunctional [28]. This finding provided an early indication of the existence of pexophagy in plants [28, 41] and supports the idea that a basal level of pexophagy continuously turns over peroxisomes in plant cells.…”

Section: Pexophagy Is Involved In Peroxisome Remodeling In Seedlingsmentioning

confidence: 79%

Pexophagy and peroxisomal protein turnover in plants

Young

Bartel

2016

Biochimica et Biophysica Acta (BBA) - Molecular Cell Research

Self Cite

View full text Add to dashboard Cite

Peroxisomes are dynamic, vital organelles that sequester a variety of oxidative reactions and their toxic byproducts from the remainder of the cell. The oxidative nature of peroxisomal metabolism predisposes the organelle to self-inflicted damage, highlighting the need for a mechanism to dispose of damaged peroxisomes. In addition, the metabolic requirements of plant peroxisomes change during development, and obsolete peroxisomal proteins are degraded. Although pexophagy, the selective autophagy of peroxisomes, is an obvious mechanism for executing such degradation, pexophagy has only recently been described in plants. Several recent studies in the reference plant Arabidopsis thaliana implicate pexophagy in the turnover of peroxisomal proteins, both for quality control and during functional transitions of peroxisomal content. In this review, we describe our current understanding of the occurrence, roles, and mechanisms of pexophagy in plants.

show abstract

Mutation of theArabidopsisLON2 peroxisomal protease enhances pexophagy

Abstract: Disrupting autophagy restores peroxisome function to an Arabidopsis lon2 mutant and reveals a role for the LON2 protease in peroxisomal matrix protein degradation.

Cited by 24 publications

References 0 publications

To deliver or to degrade – an interplay of the ubiquitin–proteasome system, autophagy and vesicular transport in plants

To deliver or to degrade – an interplay of the ubiquitin–proteasome system, autophagy and vesicular transport in plants

Peroxisomal Ubiquitin-Protein Ligases Peroxin2 and Peroxin10 Have Distinct But Synergistic Roles in Matrix Protein Import and Peroxin5 Retrotranslocation in Arabidopsis

Pexophagy and peroxisomal protein turnover in plants

Contact Info

Product

Resources

About