Four-jointed box protein 1/four-jointed protein (IPR024868)

Short name: FJX1/FJ

Overlapping homologous superfamilies


Family relationships



The mouse four-jointed box protein 1 (fjx1) gene and Drosophila four-jointed (fj) gene are homologues [PMID: 16145673, PMID: 18028897, PMID: 16059920, PMID: 10072791]. Fj encodes a partially secreted transmembrane (TM) type II glyco- protein. In Drosophila, the gene is a downstream target of the Notch signalling pathway in leg-segmentation and planar-cell polarity processes during eye development. Conserved in vertebrates, the murine homologue, fjx1, is also a direct target of Notch signalling [PMID: 16145673]. The gene is expressed in mouse brain, in the peripheral nervous system, in epithelial cells of multiple organs, and during limb development [PMID: 16145673].

The protein product is processed and secreted as a presumptive ligand [PMID: 16145673]. fjx1 binding sites have been identified at complementary locations, suggesting that fjx1 may function as a novel signalling molecule [PMID: 16145673].

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.