PICALM (E3J9R) Rabbit mAb #26765

Phosphatidylinositol-binding clathrin assembly protein (PICALM) is a clathrin-binding cytosolic protein. Clathrin is a triskelion-shaped protein that plays a major role in the formation of coated vesicles (1). Formation of these vesicles is critical for shaping the cell membrane to promote intracellular trafficking for multiple membrane trafficking pathways in the cell, including the trans-Golgi network as well as transport to and from the cell membrane and endosomal compartments. Several clathrin adaptor proteins regulate assembly and recruitment to the membrane, including AP2, EPS-15, and Epsin. PICALM, also known as clathrin assembly lymphoid myeloid leukemia protein (CALM), was identified based on genetic homology to clathrin assembly synaptic protein AP180, which as the name suggests, is also a clathrin-associated adaptor protein, particularly in the brain (2). PICALM, along with AP2 and clathrin, are one of the most abundant components of clathrin-coated vesicles, which consists of clathrin triskelia, adaptors, and other accessory proteins at specific plasma membrane sites which function to initiate vesicular budding from the membrane (3). PICALM is a single peptide chain that contains an N-terminal AP180-amino-terminal-homology (ANTH) domain, which mediates binding to phosphoinositides on the plasma membrane. The C-terminal domain of PICALM contains binding motifs for clathrin, AP2, and EPS15 (4). Interestingly, the gene that encodes PICALM has been genetically linked to neurodegenerative diseases, and alterations of PICALM’s role in clathrin-mediated endocytosis may contribute to cellular mechanisms of amyloid β pathology as well as tau accumulation and transmission (5-7).