Planar cell polarity (PCP), is a form of tissue organization that is critical for normal development. Dysfunction in PCP can result in several human cancers. PCP can be readily assessed in the Drosophila eye, by the ordered ommatidial array shown below:
Ommatidial array: PCP can be readily assessed in the Drosophila eye, by the ordered ommatidial array as shown in the image above.
One of the key factors in the PCP pathway is the cell adhesion molecule called Fat. Using a combination of genetics and biochemistry, the McNeill (Mt. Sinai, Dept. Mol. Gen.) and McQuibban labs have discovered that Fat undergoes a proteolytic cleavage that releases a soluble cytoplasmic fragment. This cleavage unmasks an embedded mitochondrial targeting motif and results in Fat import into mitochondria. Once inside mitochondria, Fat regulates changes in intracellular metabolism. This is the first example of a cell surface protein being relocated to mitochondria to orchestrate an important signaling pathway.
