Structural Analysis of Intermolecular Interactions in the Kinesin Adaptor Complex Fasciculation and Elongation Protein Zeta 1/ Short Coiled-Coil Protein (FEZ1/SCOCO)

Abstract

Cytoskeleton and protein trafficking processes, including vesicle transport to synapses, are key processes in neuronal differentiation and axon outgrowth. The human protein FEZ1 (fasciculation and elongation protein zeta 1 / UNC-76, in C. elegans), SCOCO (short coiled-coil protein / UNC-69) and kinesins (e.g. kinesin heavy chain / UNC116) are involved in these processes. Exploiting the feature of FEZ1 protein as a bivalent adapter of transport mediated by kinesins and FEZ1 protein interaction with SCOCO (proteins involved in the same path of axonal growth), we investigated the structural aspects of intermolecular interactions involved in this complex formation by NMR (Nuclear Magnetic Resonance), cross-linking coupled with mass spectrometry (MS), SAXS (Small Angle X-ray Scattering) and molecular modelling. The topology of homodimerization was accessed through NMR (Nuclear Magnetic Resonance) studies of the region involved in this process, corresponding to FEZ1 (92-194). Through studies involving the protein in its monomeric configuration (reduced) and dimeric state, we propose that homodimerization occurs with FEZ1 chains oriented in an anti-parallel topology. We demonstrate that the interaction interface of FEZ1 and SCOCO defined by MS and computational modelling is in accordance with that previously demonstrated for UNC-76 and UNC-69. SAXS and literature data support a heterotetrameric complex model. These data provide details about the interaction interfaces probably involved in the transport machinery assembly and open perspectives to understand and interfere in this assembly and its involvement in neuronal differentiation and axon outgrowth.

Fasciculation and elongation zeta‐1 protein (FEZ1) interacts with the retinoic acid receptor and participates in transcriptional regulation of the Hoxb4 gene

“…The gene expression analysis using an array of genes related to retinoic acid signaling and cells derived from brain (the tissue where FEZ1 has high expression levels) showed that sox2 gene was induced when FEZ1 was overexpressed and this was confirmed when FEZ1 was depleted and there was no sox2 activation, supporting the hypothesis that the presence of FEZ1 could be part of sox2 activation. This finding is very consistent with previous results from the orthologue of human SCOCO, BERT ( Gallus gallus short coiled‐coil protein), which was reported to participate in regulating the expression of gene sox2 in the neural plate development, and SCOCO is an important, permanent interaction partner of FEZ1 .…”

“…4.5 μL of the resulting peptide mixture was analyzed in LTQ Orbitrap Velos. Instrument parameters and software analysis were performed as previously described . The experiment was performed in duplicate.…”

“…Other studies associated the protein BERT as a regulator of the transcriptional complex of the gene sox2 and the development of the neural plate in chicken embryos . Alborghetti and colleagues (2013) further structurally characterized the complex FEZ1–SCOCO .…”

Enteric innervation combined with proteomics for the evaluation of the effects of chronic fluoride exposure on the duodenum of rats

“…This protein is an adapter of the transport mediated by kinesins considered “motor” proteins, transporting not only molecules but also organelles through a process that is dependent on ATP and microtubules. Intracellular protein transport is essential for neuronal differentiation, gene expression and cytoskeleton rearrangement 73 . Supression of FEZ-1 by si-RNA affects mitochondrial motility and neuronal morphology 74 in the CNS, and its downregulation observed after F exposure could affect enteric neurons by compromising the intracellular transport.…”

Fasciculation and elongation zeta proteins 1 and 2: From structural flexibility to functional diversity

“…Further studies about FEZ proteins’ involvement in autophagy, if it acts as a protein adaptor or scaffold for proteins above described, can shed light in neurological disorders and cancer[55-57]. It is also important to mention that two studies provided insights on SCOCO’s structure and its binding to FEZ1[58,59].…”