Phosphofurin Acidic Cluster Sorting Protein 2 (PACS2)

PACS2. The deduced 889-amino acid protein shares 54% identity with PACS1 overall, and 81% identity in the 140-amino acid cargo/adaptor-binding region. Northern blot analysis detected broad expression of a 3.8-kb PACS2 transcript, with highest expression in skeletal muscle, followed by heart, brain, pancreas, and testis. Confocal immunofluorescence of a mouse rhabdomyosarcoma cell line showed Pacs2 colocalized with an endoplasmic reticulum (ER) marker.

Pacs2 also controlled ER homeostasis and formation of ER lipid synthesizing centers that are found on mitochondria-associated membranes. In response to apoptotic inducers, Pacs2 translocated full-length Bid to mitochondria, which initiates a sequence of events including Bid truncation, release of cytochrome c, and activation of Casp3, leading to cell death.