The Bin/Amphiphysin/Rvs (BAR) domain of Protein Interacting with C Kinase 1
The BAR domain of Arfaptin-like proteins, also called the Arfaptin domain, is a dimerization and lipid binding module that can detect and drive membrane curvature. Protein Interacting with C Kinase 1 (PICK1), also called Protein kinase C-alpha-binding protein, is highly expressed in brain and testes. PICK1 plays a key role in the trafficking of AMPA receptors, which are critical for regulating synaptic strength and may be important in cellular processes involved in learning and memory. PICK1 is also critical in the early stages of spermiogenesis. Mice deficient in PICK1 are infertile and show characteristics of the human disease globozoospermia such as round-headed sperm, reduced sperm count, and severely impaired sperm motility. PICK1 may also be involved in the neuropathogenesis of schizophrenia. PICK1 contains an N-terminal PDZ domain and a C-terminal BAR domain. BAR domains form dimers that bind to membranes, induce membrane bending and curvature, and may also be involved in protein-protein interactions. The BAR domain of PICK1 is necessary for its membrane localization and activation.