Pex3p phosphorylation modulates recruitment of myosin V adapters Inp2p and Pex19p to regulate peroxisome partitioning in yeast.

. Pex3p is an integral membrane protein that contains a cytosol-exposed surface loop subject to phosphorylation. This loop is essential for the recruitment of both Inp2p and Pex19p. Phosphorylation of serine residues within the loop in response to environmental stimuli abolishes Inp2p binding to, and markedly reduces Pex19p association with, Pex3p, thereby reducing the efficiency of peroxisome partitioning between mother cell and bud. Deleting the loop in Pex3p completely abolishes peroxisome segregation. By serving as a membrane anchor for the recruitment of both inheritance factors Inp2p and Pex19p, Pex3p exerts a critical level of control over peroxisome partitioning. Media: see text Media: see text Media: see text Media: see text Media: see text.