The Autophagosome Marker Antibody Sampler Kit provides an economical means to investigate the accumulation of autophagosomes within the cell. The kit contains enough primary and secondary antibodies to perform two western blots per primary antibody.
Specificity / Sensitivity
Each antibody in the Autophagosome Marker Antibody Sampler Kit detects endogenous levels of total respective protein. Atg12 Antibody (Human Specific) recognizes free Atg12 and the Atg12-Atg5 conjugate. LC3A (D50G8) XP® Rabbit mAb and LC3B (D11) XP® Rabbit mAb may cross-react with other LC3 isoforms and have stronger reactivity with the type II form.
Source / Purification
Antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues near the amino terminus of human Atg12 protein, residues near the amino terminus of human LC3A protein, or residues near the amino terminus of human LC3B protein. Polyclonal antibodies are purified by protein A and peptide affinity chromatography.
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 has also been associated with a number of physiological processes including development, differentiation, neurodegeneration, infection, and cancer (3). The molecular machinery of autophagy was largely discovered in yeast and referred to as autophagy-related (Atg) genes. Formation of the autophagosome involves a ubiquitin-like conjugation system in which Atg12 is covalently bound to Atg5 and targeted to autophagosome vesicles (4-6). This conjugation reaction is mediated by the ubiquitin E1-like enzyme Atg7 and the E2-like enzyme Atg10 (7,8). Autophagy marker Light Chain 3 (LC3) was originally identified as a subunit of microtubule-associated proteins 1A and 1B (termed MAP1LC3) (9) and subsequently found to contain similarity to the yeast protein Apg8/Aut7/Cvt5 that is critical for autophagy (10). Three human LC3 isoforms (LC3A, LC3B, and LC3C) undergo post-translational modifications during autophagy (11-14). 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 (11-15). 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 (16).