Golgin Imh1 is involved in vesicular transport between an endosomal compartment and the Golgi apparatus []. It is targeted to the trans-Golgi network (TGN) through interaction of its GRIP domain with GTP-bound Arl1. Arl1 is an Arf-like protein which functions as a regulator of vesicular trafficking and cytoskeletal organisation []. The dimerisation of Imh1 is required for its ability to regulate GTP hydrolysis of Arl1 [].
This family consists of Arfaptin-1, Arfaptin-2, and protein kinase C-binding protein 1 (PICK1). They all contain a Bin/amphiphysin/Rvs (BAR) domain []. BAR-domain-containing proteins are key players in membrane dynamics as their crescent shape allows them to sense or generate curvature on lipid bilayers [].Arfaptin-1 and 2 have been shown to interact with Arf GTPases and Arf-like 1 (Arl1). They are recruited to trans-Golgi membranes through interaction with Arl1 [].In neurons, PICK1 forms homodimers and serves as one of the scaffolding proteins that interacts with AMPA receptors and regulates their trafficking in synaptic plasticity []. In pancreatic beta cells, it forms heteromeric BAR-domain complexes with another cytosolic lipid-binding protein, ICA69. Together they are key regulators of the formation and maturation of insulin granules [].
