Microtubule-associated proteins 1A/1B light chain 3B (LC3B)

Microtubule-associated proteins 1A/1B light chain 3B (LC3B) is a central protein in the macroautophagy pathway, essential for the formation, maturation, and cargo selection of autophagosomes (UniProt P60709). It undergoes a C-terminal cleavage by ATG4 to form the cytosolic LC3-I, which is subsequently conjugated to phosphatidylethanolamine to form LC3-II, the membrane-bound form used as a definitive hallmark of autophagic activity (PubMed: 23280503). LC3B acts as an adapter protein, interacting with LIR-containing cargo receptors like p62 to facilitate the selective degradation of cellular components such as damaged organelles or protein aggregates (PubMed: 28445460). In oncology, LC3-mediated autophagy can promote tumor survival under metabolic stress, making it a target for inhibitors like hydroxychloroquine which block the degradation of LC3-II (PubMed: 30229034). Conversely, enhancing LC3-dependent clearance is a therapeutic strategy for neurodegenerative diseases characterized by protein aggregation, such as Alzheimer's and Parkinson's (PubMed: 31160674). Current drug development also explores LC3-targeting chimeras (AUTACs) that leverage the LC3 machinery to direct specific pathogenic proteins for autophagic degradation (PubMed: 31806907).

Other names

MAP1LC3BLC3Autophagy-related protein LC3BMicrotubule-associated protein 1 light chain 3 betaATG8F

Modulation of autophagic flux through the inhibition of autophagosome-lysosome fusion or the induction of autophagosome formation and cargo recruitment.