p115 (H-300) Antibody: sc-25589

p115 Background Information
The mammalian protein p115, known also as transcytosis-associated protein (TAP), tethering factor or vesicle docking protein (VDP), and its yeast homologue Uso1p have an essential role in membrane trafficking (1-3). p115 is phosphorylated in interphase but not in mitotic cells (2). Phosphorylated p115 is localized to the cytosol, whereas the unphosphorylated form is associated with membranes, mostly of the Golgi complex (1). Upon phosphorylation of p115 at Ser942, p115 is released from the membranes (2). In mammary glands, p115 synthesis is dependent of the stage of lactation (4). Both giantin and GM130 compete for binding to the C-terminal acidic domain of p115, and p115-giantin and p115-GM130 interactions mediate independent membrane tethering events (5). The amino terminal region of p115 is required for its localization to the Golgi (1). p115 is also expressed on transcytotic vesicles, where p115 is required for vesicle fusion with the target membrane and vesicular tubular clusters (6), which are involved in ER to Golgi transport (1). Rab1 recruits p115 to coat protein complex II (COPII) vesicles during budding from the endoplasmic reticulum, where it interacts with a select set of SNAREs (7). p115 is a general factor acting within the secretory and endocytic pathways to bind transport vesicles prior to membrane fusion (6).