Identification and functional analysis of Joka2, a tobacco member of the family of selective autophagy cargo receptors
| Autor: | Anna Wawrzyńska, Małgorzata Lewandowska, Agnieszka Sirko, Jolanta Łukomska, Grzegorz Moniuszko, Rafał Gwozdecki, Frantz Liszewska, Katarzyna Zientara-Rytter, Przemyslaw Surowiecki |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Sequestosome-1 Protein
Cytoplasm Autophagy-Related Protein 8 Family Programmed cell death Nitrogen ATG8 Receptors Cytoplasmic and Nuclear Environment Biology BAG3 Gene Expression Regulation Plant Tobacco Autophagy Humans Molecular Biology Adaptor Proteins Signal Transducing Innate immune system Arabidopsis Proteins Microfilament Proteins Cell Biology Basic Research Paper Protein Structure Tertiary Cell biology Plant Leaves Microscopy Fluorescence Biochemistry Ectopic expression Carrier Proteins Sulfur |
| Zdroj: | Autophagy. 7:1145-1158 |
| ISSN: | 1554-8635 1554-8627 |
| DOI: | 10.4161/auto.7.10.16617 |
| Popis: | Two main mechanisms of protein turnover exist in eukaryotic cells: the ubiquitin-proteasome system and the autophagy-lysosomal pathway. Autophagy is an emerging important constituent of many physiological and pathological processes, such as response to nutrient deficiency, programmed cell death and innate immune response. In mammalian cells the selectivity of autophagy is ensured by the presence of cargo receptors, such as p62/SQSTM1 and NBR1, responsible for sequestration of the ubiquitinated proteins. In plants no selective cargo receptors have been identified yet. The present report indicates that structural and functional homologs of p62 and NBR1 proteins exist in plants. The tobacco protein, named Joka2, has been identified in yeast two-hybrid search as a binding partner of a small coiled-coil protein, a member of UP9/LSU family of unknown function, encoded by the UP9C gene strongly and specifically induced during sulfur deficiency. The typical domains of p62 and NBR1 are conserved in Joka2. Similarly to p62, Joka2-YFP has dual localization (cytosolic speckles and the nucleus); it forms homodimers and interacts with a member of the ATG8 family. Increased expression of Joka2 and ATG8f was observed in roots of tobacco plants grown for two days in nutrient-deficient conditions. Constitutive ectopic expression of Joka2-YFP in tobacco resulted in attenuated response (manifested by lesser yellowing of the leaves) to nutrient deficiency. In conclusion, Joka2, and presumably the process of selective autophagy, might constitute an important part of plant response to environmental stresses. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|