RESUMO
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.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/química , Dissulfetos/química , Proteínas do Tecido Nervoso/química , Proteômica/métodos , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Sequência de Aminoácidos , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/metabolismo , Linhagem Celular , Sequência Conservada , Dissulfetos/metabolismo , Humanos , Espectrometria de Massas , Modelos Moleculares , Anotação de Sequência Molecular , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Multimerização Proteica , Estrutura Terciária de Proteína , Transporte Proteico , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Espalhamento a Baixo Ângulo , Alinhamento de Sequência , Difração de Raios XRESUMO
Plastic deformation has proved to be an attractive tool for obtaining ultrafine grained and nanocrystalline metallic materials. A description of plastic deformation as a technique to create nanotexturized polytetrafluoroethylene substrates free of defects, such as pores or impurities, which has potential applications as templates for the oriented growth of organic and inorganic compounds, is presented here. The obtained morphology characterized by nanosized fibrils arrangements was revealed by atomic force microscopy. Nanofibrils with a width from 330 to 980 nm and lengths from 1.85 to 11 microm were observed on polytetrafluoroethylene substrates annealed at 330 degrees C and 390 degrees C, respectively. Wide angle X-ray scattering spectra for untreated and annealed samples show that there is a slight decrease in the amorphous component for samples annealed at 380 degrees C but not for samples annealed at 330 degrees C showing that the amorphous substrate matrix in little altered by the annealing. The pattern formation is associated with superficial polymeric domains that become large crystalline nanofibrils in an amorphous matrix.