About PACE4
This gene encodes a member of the subtilisin-like proprotein convertase family, which includes proteases that process protein and peptide precursors trafficking through regulated or constitutive branches of the secretory pathway. The encoded protein undergoes an initial autocatalytic processing event in the ER to generate a heterodimer which exits the ER and sorts to the trans-Golgi network where a second autocatalytic event takes place and the catalytic activity is acquired. The encoded protease is constitutively secreted into the extracellular matrix and expressed in many tissues, including neuroendocrine, liver, gut, and brain. This gene encodes one of the seven basic amino acid-specific members which cleave their substrates at single or paired basic residues. Some of its substrates include transforming growth factor beta related proteins, proalbumin, and von Willebrand factor. This gene is thought to play a role in tumor progression and left-right patterning. Alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Feb 2014]

About PE
Phycoerythrin (PE, R-PE) is a red-emitting fluorescent protein-chromophore complex that can be excited the 488-nm blue, 532-nm green, or 561-nm yellow-green laser with increasing efficiency and captured with a 586/14 nm bandpass filter. PE has an excitation peak at 565 nm and an emission peak at 578 nm. PE is 240kD in size and has an extinction coefficient of ~2x10^6 which makes it one of the brightest fluorophores available and a potent donor upon which to build tandem fluorophores with longer Stoke's Shifts.