title: Over-expression of GFP-FEZ1 causes generation of multi-lobulated nuclei mediated by microtubules in HEK293 cells.
abstract: FEZ1 (Fasciculation and elongation protein zeta 1) is an ortholog of the Caenorhabditis elegans protein UNC-76, involved in neuronal development and axon outgrowth, in that worm. Mammalian FEZ1 has already been reported to cooperate with PKC-zeta in the differentiation and polarization of PC12 neuronal cells. Furthermore, FEZ1 is associated with kinesin 1 and JIP1 to form a cargo-complex responsible for microtubule based transport of mitochondria along axons. FEZ1 can also be classified as a hub protein, since it was reported to interact with over 40 different proteins in yeast two-hybrid screens, including at least nine nuclear proteins. Here, we transiently over-expressed GFP-FEZ1full in human HEK293 and HeLa cells in order to study the sub-cellular localization of GFP-FEZ1. We observed that over 40% of transiently transfected cells at 3 days post-transfection develop multi-lobulated nuclei, which are also called flower-like nuclei. We further demonstrated that GFP-FEZ1 localizes either to the cytoplasm or the nuclear fraction, and that the appearance of the flower-like nuclei depends on intact microtubule function. Finally, we show that FEZ1 co-localizes with both, alpha- and especially with gamma-tubulin, which localizes as a centrosome like structure at the center of the multiple lobules. In summary, our data suggest that FEZ1 has an important centrosomal function and supply new mechanistic insights to the formation of flower-like nuclei, which are a phenotypical hallmark of human leukemia cells.
authors.affiliation: Laboratório Nacional de Luz Síncrotron, Campinas SP, Brazil; Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brazil.
authors.forename: Daniel C F
authors.initials: DC
authors.lastname: Lanza
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Trindade
authors.forename: Eliana M
authors.initials: EM
authors.lastname: Assmann
authors.forename: Jörg
authors.initials: J
authors.lastname: Kobarg
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D018385:Centrosome / Q000378:metabolism / Q000648:ultrastructure; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008870:Microtubules / Q000378:metabolism*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins; D009479:Neuropeptides / Q000235:genetics / Q000378:metabolism; D015739:Nocodazole / Q000378:metabolism; D010641:Phenotype; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D020539:Sequence Analysis, Protein; D014404:Tubulin / Q000378:metabolism; D050257:Tubulin Modulators / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; C528597:FEZ1 protein, human; C118711:LZTS1 protein, human; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D011993:Recombinant Fusion Proteins; D014404:Tubulin; D050257:Tubulin Modulators; D025521:Tumor Suppressor Proteins; C105447:UNC-76 protein, C elegans; D015739:Nocodazole