Abstract
Autophagy is an intracellular process for vacuolar degradation of cytoplasmic components. The molecular machinery responsible for yeast and mammalian autophagy has begun to be elucidated at the cellular level. A genome-wide search revealed significant conservation among autophagy genes in yeast and Arabidopsis. Up till now, however, there is no report about rice autophagy associated genes. Here we cloned OsAtg8 and OsAtg4 from Oryza sativa and detected their expression patterns in various tissues. Immunoblotting analysis showed that carboxyl terminus of OsAtg8 can be cleaved in yeast cell. Mutation analysis revealed that the conserved Gly117 residue of OsAtg8 was essential for its characteristic C-terminal cleavage as similar to that found in mammalian and yeast Atg8. We further proved that OsAtg8 interacted with OsAtg4, and this interaction was not affected by the conserved Gly117 mutation. Our results demonstrate that Atg8 conjugation pathway is conserved in rice and may play important roles in rice autophagy.
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References
Klionsky DJ, Emr SD (2000) Autophagy as a regulated pathway of cellular degradation. Science 290:1717–1721
Harding TM, Morano KA, Scott SV, Klionsky DJ (1995) Isolation and characterization of yeast mutants in the cytoplasm to vacuole protein targeting pathway. J Cell Biol 131:591–602
Thumm M, Egner R, Koch B, Schlumpberger M, Straub M, Veenhuis M, Wolf DH (1994) Isolation of autophagocytosis mutants of Saccharomyces cerevisiae. FEBS Lett 349:275–280
Tsukada M, Ohsumi Y (1993) Isolation and characterization of autophagy-defective mutants of Saccharomyces cerevisiae. FEBS Lett 333:169–174
Wang CW, Klionsky DJ (2003) The molecular mechanism of autophagy. Mol Med 9:65–76 Review
Noda T, Suzuki K, Ohsumi Y (2002) Yeast autophagosomes: de novo formation of a membrane structure. Trends Cell Biol 12:231–235 Review
Abeliovich H, Klionsky DJ (2001) Autophagy in yeast: mechanistic insights and physiological function. Microbiol Mol Biol Rev 65:463–479 Review
Ichimura Y, Kirisako T, Takao T, Satomi Y, Shimonishi Y, Ishihara N, Mizushima N, Tanida I, Kominami E, Ohsumi M, Noda T, Ohsumi Y (2000) A ubiquitin-like system mediates protein lipidation. Nature 408:488–492
Lang T, Schaeffeler E, Bernreuther D, Bredschneider M, Wolf DH, Thumm M (1998) Aut2p and Aut7p, two novel microtubule-associated proteins are essential for delivery of autophagic vesicles to the vacuole. EMBO J 17(13):3597–3607
Kirisako T, Baba M, Ishihara N, Miyazawa K, Ohsumi M, Yoshimori T, Noda T, Ohsumi Y (1999) Formation process of autophagosome is traced with Apg8/Aut7p in yeast. J Cell Biol 147:435–446
Kirisako T, Ichimura Y, Okada H, Kabeya Y, Mizushima N, Yoshimori T, Ohsumi M, Takao T, Noda T, Ohsumi Y (2000) The reversible modification regulates the membrane-binding state of Apg8/Aut7 essential for autophagy and the cytoplasm to vacuole targeting pathway. J Cell Biol 151:263–276
Kabeya Y, Mizushima N, Ueno T, Yamamoto A, Kirisako T, Noda T, Kominami E, Ohsumi Y, Yoshimori T (2000) LC3, a mammalian homologue of yeast Apg8p, is localized in autophagosome membranes after processing. EMBO J 19:5720–5728
He H, Dang Y, Dai F, Guo Z, Wu J, She X, Pei Y, Chen Y, Ling W, Wu C, Zhao S, Liu JO, Yu L (2003) Post-translational modifications of three members of the human MAP1LC3 family and detection of a novel type of modification for MAP1LC3B. J Biol Chem 278:29278–29287
Wu J, Dang Y, Su W, Liu C, Ma H, Shan Y, Pei Y, Wan B, Guo J, Yu L (2006) Molecular cloning and characterization of rat LC3A and LC3B-Two novel markers of autophagosome. Biochem Biophys Res Commun 339:437–442
Hanaoka H, Noda T, Shirano Y, Kato T, Hayashi H, Shibata D, Tabata S, Ohsumi Y (2002) Leaf senescence and starvation-induced chlorosis are accelerated by the disruption of an Arabidopsis autophagy gene. Plant Physiol 129:1181–1193
Marty F (1999) Plant vacuoles. Plant Cell 11:587–600
Doelling JH, Walker JM, Friedman EM, Thompson AR, Vierstra RD (2002) The APG8/12-activating enzyme APG7 is required for proper nutrient recycling and senescence in Arabidopsis thaliana. J Biol Chem 277:33105–33114
Yoshimoto K, Hanaoka H, Sato S, Kato T, Tabata S, Noda T, Ohsumi Y (2004) Processing of ATG8s, ubiquitin-like proteins, and their deconjugation by ATG4s are essential for plant autophagy. Plant Cell 16:2967–2983
Thompson AR, Doelling JH, Suttangkakul A, Vierstra RD (2005) Autophagic nutrient recycling in Arabidopsis directed by the ATG8 and ATG12 conjugation pathways. Plant Physiol 138:2097–2110
Xiong Y, Contento AL, Bassham DC (2005) AtATG18a is required for the formation of autophagosomes during nutrient stress and senescence in Arabidopsis thaliana. Plant J 42:535–546
Ketelaar T, Voss C, Dimmock SA, Thumm M, Hussey PJ (2004) Arabidopsis homologues of the autophagy protein Atg8 are a novel family of microtubule binding proteins. FEBS Lett 567:302–306
Marino G, Uria JA, Puente XS, Quesada V, Bordallo J, Lopez-Otin C (2003) Human autophagins, a family of cysteine proteinases potentially implicated in cell degradation by autophagy. J Biol Chem 278:3671–3678
Hemelaar J, Lelyveld VS, Kessler BM, Ploegh HL (2003) A single protease, Apg4B, is specific for the autophagy-related ubiquitin-like proteins GATE-16, MAP1-LC3, GABARAP, and Apg8L. J Biol Chem 278:51841–51850
Tanida I, Sou YS, Ezaki J, Minematsu-Ikeguchi N, Ueno T, Kominami E (2004) HsAtg4B/HsApg4B/autophagin-1 cleaves the carboxyl termini of three human Atg8 homologues and delipidates microtubule-associated protein light chain 3- and GABAA receptor-associated protein-phospholipid conjugates. J Biol Chem 279:36268–36276
Kabeya Y, Mizushima N, Yamamoto A, Oshitani-Okamoto S, Ohsumi Y, Yoshimori T (2004) LC3, GABARAP and GATE16 localize to autophagosomal membrane depending on form-II formation. J Cell Sci 117:2805–2812
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This work was supported by the National Natural Science Foundation of China (Grant No. 30370136).
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Su, W., Ma, H., Liu, C. et al. Identification and characterization of two rice autophagy associated genes, OsAtg8 and OsAtg4. Mol Biol Rep 33, 273–278 (2006). https://doi.org/10.1007/s11033-006-9011-0
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DOI: https://doi.org/10.1007/s11033-006-9011-0