This is a family of eukaryotic proteins thought to be involved in axonal outgrowth and fasciculation [1]. The N-terminal regions of these sequences are less conserved than the C-terminal regions, and are highly acidic [1]. The C. elegans homolog, UNC-76 (Swiss:Q7JNU9), may play structural and signalling roles in the control of axonal extension and adhesion (particularly in the presence of adjacent neuronal cells [2]) and these roles have also been postulated for other FEZ family proteins [1]. Certain homologs have been definitively found to interact with the N-terminal variable region (V1) of PKC-zeta, and this interaction causes cytoplasmic translocation of the FEZ family protein in mammalian neuronal cells [2]. The C-terminal region probably participates in the association with the regulatory domain of PKC-zeta [2]. The members of this family are predicted to form coiled-coil structures [2,3], which may interact with members of the RhoA family of signalling proteins [2], but are not thought to contain other characteristic protein motifs [3]. Certain members of this family are expressed almost exclusively in the brain, whereas others (such as FEZ2, Swiss:Q76LN0) are expressed in other tissues, and are thought to perform similar but unknown functions in these tissues [3].

1: The Caenorhabditis elegans gene unc-76 and its human homologs define a new gene family involved in axonal outgrowth and fasciculation. Bloom L, Horvitz HR; Proc Natl Acad Sci U S A 1997;94:3414-3419. PMID:9096408

2: Mammalian homologue of the Caenorhabditis elegans UNC-76 protein involved in axonal outgrowth is a protein kinase C zeta-interacting protein. Kuroda S, Nakagawa N, Tokunaga C, Tatematsu K, Tanizawa K; J Cell Biol 1999;144:403-411. PMID:9971736

3: Identification of a tissue-non-specific homologue of axonal fasciculation and elongation protein zeta-1. Fujita T, Ikuta J, Hamada J, Okajima T, Tatematsu K, Tanizawa K, Kuroda S; Biochem Biophys Res Commun 2004;313:738-744. PMID:14697253