title: Human FEZ1 protein forms a disulfide bond mediated dimer: implications for cargo transport.
abstract: The human proteins FEZ1 (fasciculation and elongation protein zeta 1) and FEZ2 are orthologs of the protein UNC-76 from C. elegans, involved in the growth and fasciculation of the worms axon. Pull down assays showed that the protein FEZ1 interacts with other proteins (e.g., the protein SCOCO, short coiled-coil protein), mitochondria, and vesicles. These components may therefore represent cargoes to be transported along the microtubule, and the transport may be mediated through FEZ1 reported binding to kinesins (KIF3A). We previously showed that FEZ1 dimerizes in its N-terminal region and interacts with other proteins, including the candidate cargoe proteins, through its C-terminus. Here, we studied the fragment FEZ1(92-194) as well as full-length 6xHis-FEZ1 (1-392) in vitro and endogenous FEZ1 isolated from HEK 293 cells and were able to demonstrate the formation of an intermolecular disulfide bond through FEZ1 Cys-133, which appears to be essential for dimerization. This disulfide bond may be important for the FEZ1 role as a dimeric and bivalent transport adaptor molecule, since it establishes a strong link between the monomers, which could be a prerequisite for the simultaneous binding of two cargoes.
authors.affiliation: Laboratório Nacional de Biociências, Centro Nacional de Pesquisa em Energia e Materiais, Campinas SP, Brazil.
authors.forename: M R
authors.initials: MR
authors.lastname: Alborghetti
authors.forename: A S
authors.initials: AS
authors.lastname: Furlan
authors.forename: J C
authors.initials: JC
authors.lastname: Silva
authors.forename: A F
authors.initials: AF
authors.lastname: Paes Leme
authors.forename: I C L
authors.initials: IC
authors.lastname: Torriani
authors.forename: J
authors.initials: J
authors.lastname: Kobarg
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D015815:Cell Adhesion Molecules / Q000737:chemistry / Q000378:metabolism; D002460:Cell Line; D017124:Conserved Sequence; D004220:Disulfides / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D013058:Mass Spectrometry; D008958:Models, Molecular; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D055503:Protein Multimerization; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D040901:Proteomics / Q000379:methods*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D053838:Scattering, Small Angle; D016415:Sequence Alignment; D014961:X-Ray Diffraction
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D015815:Cell Adhesion Molecules; D004220:Disulfides; C528597:FEZ1 protein, human; C481525:FEZ2 protein, human; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins