A monoclonal antibody for in vivo detection of peroxisome-associated PTS1 receptor.

PEX5 is a key protein of the peroxisomal protein import machinery. This cycling receptor binds newly synthesized proteins with a peroxisomal targeting signal type 1 in the cytosol and directs them to the peroxisomal membrane. There, PEX5, together with its docking protein, forms a transient membrane-spanning channel that enables cargo-transport across the membrane. Through interaction with other multimeric membrane complexes, the receptor is released from the membrane back to the cytosol. Very little is known about the various conformational states of the receptor during its cycling. Here we report the generation and characterization of a mouse monoclonal antibody that recognizes in vivo primarily the membrane-associated form of the human PTS1 receptor.