SignalSilence ® LC3A siRNA I

Autophagy is a catabolic process for the autophagosomic-lysosomal degradation of bulk cytoplasmic contents (1,2). Autophagy is generally activated by conditions of nutrient deprivation, but it has also been associated with a number of physiological processes including development, differentiation, neurodegenerative diseases, infection, and cancer (3). Autophagy marker Light Chain 3 (LC3) was originally identified as a subunit of microtubule-associated proteins 1A and 1B (termed MAP1LC3) (4) and subsequently found to contain similarity to the yeast protein Apg8/Aut7/Cvt5 critical for autophagy (5). Three human LC3 isoforms (LC3A, LC3B, and LC3C) undergo posttranslational modifications during autophagy (6-9). Cleavage of LC3 at the carboxy terminus immediately following synthesis yields the cytosolic LC3-I form. During autophagy, LC3-I is converted to LC3-II through lipidation by a ubiquitin-like system involving Atg7 and Atg3 that allows for LC3 to become associated with autophagic vesicles (6-10). The presence of LC3 in autophagosomes and the conversion of LC3 to the lower migrating form, LC3-II, have been used as indicators of autophagy (11). 1.Reggiori, F. and Klionsky, D.J. (2002) Eukaryot. Cell 1, 11-21. 2.Codogno, P. and Meijer, A.J. (2005) Cell Death Differ. 12 Suppl 2, 1509-18. 3.Levine, B. and Yuan, J. (2005) J. Clin. Invest. 115, 2679-88. 4.Mann, S.S. and Hammarback, J.A. (1994) J. Biol. Chem. 269, 11492-97. 5.Lang, T. et al. (1998) EMBO J. 17, 3597-607. 6.Kabeya, Y. et al. (2000) EMBO J. 19, 5720-28. 7.He, H. et al. (2003) J. Biol. Chem. 278, 29278-87. 8.Tanida, I. et al. (2004) J. Biol. Chem. 279, 47704-10. 9.Wu, J. et al. (2006) Biochem. Biophys. Res. Commun. 339, 437-42. 10.Ichimura, Y. et al. (2000) Nature 408, 488-92. 11.Kabeya, Y. et al. (2004) J. Cell Sci. 117, 2805-12.