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| Author(s): |
Marcos Rodrigo Alborghetti
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2011-08-07 |
| Examining board members: |
Jörg Kobarg;
Deborah Schechtman;
Andrea Balan;
Carmen Veríssima Ferreira;
Hiroshi Aoyama
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| Advisor: | Jörg Kobarg |
| Abstract | |
The human proteins FEZ1 and FEZ2 (fasciculation and elongation protein zeta 1) are orthologs of the protein UNC-76 from C. elegans, involved in growth and fasciculation of axons, through interactions that involve kinesins, mitochondria and synaptic vesicles. Moreover, some evidence suggests involvement of FEZ1 in the etiology of schizophrenia, in addition to the viral cycle and resistance to chemotherapy. Its structure intrinsically disordered, with coiled-coil along the sequence, can contribute to its function. We have explored the molecular evolution of the FEZ protein family with emphasis on the vertebrata branch. Analyzing the interactome profile of the FEZ1 and FEZ2 from Homo sapiens and UNC-76 from C. elegans we observed a conserved pattern of protein-protein interactions among FEZ1 and UNC-76 that explain the ability of FEZ1 to rescue the defects caused by unc-76 mutations in nematodes, according to Bloom and co-workers in 1997. Furthermore, we characterized the interaction between FEZ1 and SCOCO (short coiled-coil protein) by SAXS (Small Angle X-ray Scattering). This interaction has been previously reported between their orthologs UNC-76 and UNC-69 that cooperate in axonal outgrowth. A heterotetrameric state was observed, which consists of two GST-SCOCO molecules attached to two FEZ1 molecules. By PAGE (Polyacrylamide Gel Electrophoresis), SAXS, Mass Spectrometry and Nuclear Magnetic Resonance we defined that FEZ1 dimerizes involving formation of disulfide bond. In vivo this covalent mediated dimeric state could be important for kinesin mediated protein transport along the microtubule. Thereby, FEZ1 may be classified as a dimeric and bivalent transport adaptor, essential to axon outgrowth and normal pre-synaptic organization and transport of cargoes. The aggregation of new interaction partners found for the FEZ2 protein could be interpreted as the acquisition of new molecular functions and may have occurred in the early stages of chordate evolution (AU) | |