MAP1LC3A Human Recombinant Protein

MAP1A and MAP1B are microtubule-associated proteins which mediate the physical interactions between microtubules and components of the cytoskeleton. MAP1A and MAP1B each consist of a heavy chain subunit and multiple light chain subunits. The protein encoded by this gene is one of the light chain subunits and can associate with either MAP1A or MAP1B. Two transcript variants encoding different isoforms have been found for this gene. The expression of variant 1 is suppressed in many tumor cell lines, suggesting that may be involved in carcinogenesis. [provided by RefSeq, Feb 2012]

LC3A: is a ubiquitin-like protein that is a constituent of the ATG8-conjugation system, one of two evolutionarily conserved phosphatidylethanolamine conjugation systems necessary for the formation of the autophagosome. The human ATG8 system includes seven ubiquitin-like light chain proteins (LCPs) that are homologs of yeast LC3: MAP1LC3A, -B, -C, GABARAP, GABARAPL1, -2, and -3. Pro-LCPs are cleaved by ATG4B to expose a C-terminal glycine residue, the cytosolic LCP-I form. The exposed C-terminus is conjugated to the head group amine of phosphatidylethanolamine (PE) through an amide bond by a sequence of ubiquitination-like reactions that involves an E1 (ATG7), an E2 (ATG3), and an E3 (a complex including ATG5, ATG12, and ATG16L). The PE-congugated form (LCP-II) is tightly associated with the autophagosomal membrane. The LCP-II forms can also be delipidated by the ATG4 proteases: most of the LCPs are delipidated and liberated from the membrane before autophagosomes fuse with lysosomes. Two isoforms of the human protein are produced by alternative splicing.

Protein type: Autophagy; Microtubule-binding; Ubiquitin-like modifier; Vesicle

Chromosomal Location of Human Ortholog: 20q11.22

Cellular Component: autophagic vacuole; cytosol

Molecular Function: microtubule binding; phosphatidylethanolamine binding; phospholipid binding; protein binding; ubiquitin protein ligase binding

Biological Process: autophagic vacuole formation; cellular response to nitrogen starvation; macroautophagy; mitochondrion degradation