Cell-type specific dendritic morphologies emerge via complex growth mechanisms modulated by intrinsic and extrinsic signaling coupled with activity-dependent regulation. Combined, these processes converge on cytoskeletal effectors to direct dendritic arbor development, stabilize mature architecture, and facilitate structural plasticity. Transcription factors (TFs) function as essential cell intrinsic regulators of dendritogenesis involving both combinatorial and cell-type specific effects, however the molecular mechanisms via which these TFs govern arbor development and dynamics remain poorly understood. Studies in Drosophila dendritic arborization (da) sensory neurons have revealed combinatorial roles of the TFs Cut and Knot in modulating dendritic morphology, however putative convergent nodal points of Cut/Knot cytoskeletal regulation remain elusive. Here we use a combined neurogenomic, bioinformatic, and genetic approach to identify and molecularly characterize downstream effectors of these TFs. From these analyses, we identified Formin3 (Form3) as a convergent transcriptional target of both Cut and Knot. We demonstrate that Form3 functions cell-autonomously in class IV (CIV) da neurons to stabilize distal higher order branching along the proximal-distal axis of dendritic arbors. Furthermore, live confocal imaging of multi-fluor cytoskeletal reporters and IHC analyses reveal that form3 mutants exhibit a specific collapse of the dendritic microtubule (MT) cytoskeleton, the functional consequences of which include defective dendritic trafficking of mitochondria and satellite Golgi. Biochemical analyses reveal Form3 directly interacts with MTs via the FH1/FH2 domains. Form3 is predicted to interact with two alpha-tubulin N-acetyltransferases (ATAT1) suggesting it may promote MT stabilization via acetylation. Analyses of acetylated dendritic MTs supports this hypothesis as defects in form3 lead to reductions, whereas overexpression promotes increases in MT acetylation. Neurologically, mutations in Inverted Formin 2 (INF2; the human ortholog of form3) have been causally linked to dominant intermediate Charcot-Marie-Tooth (CMT) disease E. CMT sensory neuropathies lead to distal sensory loss resulting in a reduced ability to sense heat, cold, and pain. Intriguingly, disruption of form3 function in CIV nociceptive neurons results in a severe impairment in nocifensive behavior in response to noxious heat, which can be rescued by expression of INF2 revealing shared primordial functions in regulating nociception and providing novel mechanistic insights into the potential etiological bases of CMT sensory neuropathies.

Stomata are specialized plant structures required for gaseous exchange with the outer environment. During stomata formation, the cytoskeleton plays an important role in controlling the division of the individual cells leading to the generation of the stomata complex. Two mutants that affect microfilament and microtubule organization in subsidiary mother cells include brk1 and dcd1. While only 20% of the subsidiary cells in the brk1 and dcd1 single mutants are abnormally shaped, it was reported that there is a synergistic effect between the brk1 and dcd1 mutations in the brk1; dcd1 double mutant since 100% of the subsidiary cells are abnormal. The focus of this research is to try to understand this synergistic effect by investigating the actin cytoskeleton and nuclear position in the single and double mutants. The reported results include the observation that the size of actin patch was largest in the wild-type subsidiary mother cells (SMCs) and smallest in dcd1 and brk1; dcd1 SMCs and that brk1 and brk1; dcd1 double mutants had fewer actin patches than wild-type and dcd1 SMCs. Additionally, we observed that some SMCs that did not have actin patches still underwent nuclear migration suggesting that nuclear migration may not be solely dependent on actin patch formation. Finally, during SMC cytokinesis, a large percentage of double mutant (brk1; dcd1) cells showed an off-track development of the phragmoplast as compared to the single mutants and the wild-type plant explaining the large number of abnormally shaped subsidiary cells in the double mutants.

Ciliopathies are a group of disorders that arise from ciliary dysfunction. Meckelin (MKS3 or TMEM67) is a conserved transmembrane protein found at the transition zone of ciliated cells. In humans MKS3 is one of 3 genes linked to the ciliopathy Meckel Syndrome. This disease is characterized by occipital meningioencephalocoele, polycystic kidneys, fibrotic changes to the liver, postnatal polydactyly and situs inversus. Paramecium tetraurelia is a single celled ciliated eukaryote. Its surface is organized of a meshwork of cortical units that run the length of the cell. At the center of the cortical units are either one or two basal bodies. In two basal body units only the posterior basal body is ciliated. From the ciliated basal body, three rootlets project in stereotypical orientations: the post-ciliary rootlet projects posteriorly, the transverse microtubule projects toward the adjacent basal body row and the striated rootlet projects anteriorly. Both the post-ciliary rootlet and transverse microtubule are microtubule-based structures. The striated rootlet is composed of multiple subunits that are predicted to have conserved segmented coiled coil domains known as SF-Assemblin domains. In Picariello at al., 2014, we showed that MKS3 is present in the transition zone of Paramecium tetraurelia and that RNAi for MKS3 leads to global ciliary loss. Additionally, RNAi for MKS3 results in the disorganization of the basal body rows. Within the areas of disorganization, the basal bodies along with their striated rootlets, post-ciliary rootlets and transverse microtubules are rotated away from their expected orientation. Interestingly, the post-ciliary rootlet and transverse microtubule are still attached at the expected angles relative to each other within the areas of disorganization. Initial GST pull-down experiments using the coiled coil domain of MKS3 suggest a potential interaction between MKS3 and the striated rootlet family members KdC1 and KdB2. To test potential interactions between MKS3 and the striated rootlet we identified 27 potential striated rootlet family members in Paramecium. Full-length sequences for 13 of these genes were marked at their N-terminus with a 3x FLAG sequence. Components with a conserved SF-Assemblin domain were distributed uniformly within the striated rootlet. Components lacking the SF-Assemblin domain were found in various cellular locations, but not within the striated rootlet. GST pull-down experiments utilizing the MKS3 C-terminus as bait were performed using cells expressing the FLAG-tagged striated rootlet family members. Unfortunately a clear interaction between MKS3 and the striated rootlet remains elusive. The organized nature of the surface of Paramecium has allowed us to identify a previously unrealized function for MKS3. Our immunofluorescence data suggest that MKS3 functions outside the transition zone to maintain basal body row organization by potentially contributing to a link between the basal body and the striated rootlet. Without the link, the migrating basal bodies are free to rotate and project their rootlets in the wrong directions. Although the nature of the link remains elusive, the identification of disorganized basal body rows upon MKS3 reduction suggests that, in addition to ciliary dysfunction, basal body polarity defects may contribute to the development of MKS.

Rice blast disease is caused by the filamentous ascomycete fungus Magnaporthe oryzae and is the most destructive disease of cultivated rice. The pathogen elaborates a specialized infection structure called the appressorium. The morphological and physiological transitions that lead to appressorium formation of M. oryzae are stimulated through perception of environmental signals and are tightly regulated by cell cycle checkpoints. External stimuli are internalized by a variety of intracellular MAP kinase signaling pathways, and the major pathway regulating appressorium morphogenesis and plant infection is the Pmk1 MAP kinase signaling pathway. The central kinase, Pmk1, is required for appressorium morphogenesis and the homeobox and C2/H2 Zn-finger domain transcription factor, called Mst12, is required for appressorium formation and tissue invasion. The Mst12 null mutant is able to form melanised appressoria, but it is non-pathogenic. To understand the mechanism of appressorium morphogenesis and penetration peg formation, genome-wide comparative transcriptional profiling analysis was performed for the Δpmk1 and Δmst12 mutant using RNA-seq and HiSeq 2000 sequencing. This thesis reports the identification of gene sets regulated by the Pmk1 signalling pathway and defines the sub-set of these genes regulated by Mst12. I show that a hierarchy of transcription factors is likely to operate downstream of Pmk1 to regulate the main processes required for appressorium morphogenesis and plant infection. I also report the role of Mst12 in cytoskeletal re-organisation and show that it is necessary for septin-dependent F-actin polymerisation at the base on the appressorium prior to plant infection. This is consistent with the major transcriptional changes observed by RNA-seq. The thesis also reports experiments that strongly suggest that appressorium mediated plant penetration is regulated by an S-phase checkpoint which operates independently of the conventional DNA damage and repair response, and the Cds1 and Chk1 checkpoint kinases. Transcriptional profiling results are consistent with the S-phase checkpoint operating downstream of the Pmk1 MAP kinase signalling pathway. An integrated model for the operation of the Pmk1/Mst12 signalling pathways and the hierarchical control of appressorium morphogenesis in the rice blast fungus is presented.

Microtubular cytoskeleton is involved in many processes in plant cells, including cell division, growth and development. Other proteins enable its functions by modulation of its dynamics and organization and by mediation of functional and structural interaction with other cell structures. Identification of the mediating proteins and the functions of these interactions under specific conditions were the main aims of the thesis. Membrane proteins interacting with microtubules were identified using biochemical methods. Surprisingly, the identified proteins co-sedimenting with microtubules were not members of the "classical" microtubule associated proteins (MAPs). There were enzymes, chaperones and plant specific proteins among them. For further studies, the identified microtubule-associated heat-shock protein 90 (Hsp90_MT) was chosen. Recombinant Hsp90_MT binds directly to microtubules and tubulin dimers in vitro. The ATP-binding pocket is not responsible for this association. In BY-2, Hsp90_MT co-localizes with phragmoplast and cortical microtubules and is involved in microtubule recovery after their depolymerization during cold treatment. In plants, Hsp90 is involved in cell cycle progression, its inhibition causes cell-cycle arrest in G1 phase. Based on literature search for animal proteins...

Thesis advisor: David Burgess / This doctoral thesis addresses two central topics divided into separate chapters. In Chapter 1: The cortical response to RhoA is regulated during mitosis, experimental findings using sea urchin embryos are presented that demonstrate that the small GTPase RhoA participates in positive signaling for cell division and that this activity is negatively regulated prior to anaphase. In a second series of experiments, myosin phosphatase is shown to be a central negative regulator of myosin activity during the cell cycle through metaphase of mitosis and experimental findings support the conclusion that myosin phosphatase opposes RhoA signaling until anaphase onset. These experiments also reveal that myosin activation alone is insufficient to stimulate cortical contractions during S phase and during metaphase arrest following activation of the spindle checkpoint. In Chapter 2: Annotation of cytoskeletal and motility proteins in the sea urchin genome assembly, as part of a collaborative project, homologs of cytoskeletal genes and gene families were derived and annotated from the sea urchin genome assembly. In addition, phylogenetic analysis of multiple gene families is presented based on these findings. / Thesis (PhD) — Boston College, 2008. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.

Thesis advisor: Marc-Jan Gubbels / Apicomplexan parasites like Toxoplasma gondii have a complex life cycle comprising of transitions between different hosts, different organ systems and between the extracellular and intracellular milieu. The parasite must thus adjust itself and its cellular processes in accordance with its environment. In this dissertation, I have focused on such stage specific behaviors of three distinct intermediate filament-like proteins as well as a glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase 1 (GAPDH1). These proteins relocate from the cytosol to the unique cortical membrane skeleton of non-dividing parasites. The intermediate filament-like proteins IMC7, 12 and 14, localize exclusively to the mature cytoskeleton. One model of function was that these proteins differentially stabilized mother and budding daughter cytoskeletons in the division process, but we ruled out this role for the individual proteins, as they are not essential for the lytic cycle of the parasite. However, we determined that IMC7 and IMC14 are contributing to the maintenance of rigidity of the cytoskeleton under osmotic stress conditions in extracellular parasites. In addition, IMC14 is critical in cell cycle progression as its depletion results in the formation of multiple daughters per division round. When the parasite egresses from the host cell, glycolytic enzyme GAPDH1 translocates to the cortex. The functional role of GAPDH1 in the parasite and the mechanism of its cortical translocation are deciphered based on the 2.25Å resolution crystal structure of the GAPDH1 holoenzyme in a quaternary complex. These studies identified that GAPDH1’s enzymatic function is essential for intracellular replication but we confirmed the previous reports that glycolysis is not strictly essential in presence of excess L-glutamine. We identify, for the first time, S-loop phosphorylation as a novel, critical regulator of enzymatic activity that is consistent with the notion that the S-loop is critical for cofactor binding, allosteric activation and oligomerization. We show that neither enzymatic activity nor phosphorylation state correlate with the ability to translocate to the cortex. However, we demonstrate that association of GAPDH1 with the cortex is mediated by Cysteine 3 in the N-terminus, likely by palmitoylation. Overall, glycolysis and cortical translocation are functionally decoupled by post-translational modifications. Collectively, the discoveries made in this dissertation reveal unprecedented detail in mechanism and function of cortical protein translocation and thereby identifying new drug targets. / Thesis (PhD) — Boston College, 2017. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.

Les bactéries magnétotactiques synthétisent des organites spécialisés appelés magnétosomes. Ils sont composés d'un cristal magnétique entouré d'une membrane et de protéines spécifiques. Arrangés en chaîne dans la bactérie, ils orientent la bactérie dans le champ magnétique, ce qui simplifierait sa recherche d’environnements microaérophiles. Dans le génome de toutes les souches magnétotactiques séquencées, l'îlot génomique de magnétotaxie contient les gènes impliqués dans la formation des magnétosomes. Nous avons procédé à l’annotation du génome de la souche magnétotactique marine QH-2 et montré que la région du génome codant les gènes de la magnétotaxie n'est, dans ce cas, pas définie comme un îlot génomique, bien qu’elle ait été acquise par transfert latéral de gènes. Dans le génome de M. magneticum AMB-1, nous avons identifié un nouvel îlot génomique de petite taille que nous avons appelé l'îlet de magnétotaxie portant 7 gènes homologues à des gènes liés à la synthèse des magnétosomes. Pour répondre à la question de la fonction biologique de cet îlet génomique, nous avons examiné le rôle de l'un des sept gènes, mamK-like. MamK-like exprimée dans E. coli forme des filaments, comme observé pour MamK. La polymérisation in vitro des deux protéines est également comparable, mais présente des différences structurales. En outre, nous démontrons que mamK-like est transcrite dans AMB-1 de type sauvage et dans le mutant ΔmamK. Par immuno-marquage, nous montrons la présence d'un filament dans le mutant ΔmamK, probablement dû à MamK-like. Nous émettons l'hypothèse que ce filament contribue à maintenir l’organisation en chaîne des magnétosomes dans la souche mutante. / Magnetotactic bacteria synthesise specialised organelles called magnetosomes. They are composed of a magnetic crystal surrounded by a lipid bilayer and specific proteins. Arranged in chains, they orient magnetotactic bacteria in the geomagnetic field, thereby simplifying their search for their microaerophilic environments. In each sequenced magnetotactic strain, the magnetotaxis genomic island contains the genes involved in magnetosomes formation. Our annotation of the newly sequenced genome of the magnetotactic strain QH-2 shows that the region coding the magnetotaxis genes is not a genomic island, though it has been acquired by lateral genes transfer. In the genome of M. magneticum AMB-1 we identified a new, small genomic island we termed the magnetotaxis islet, encoding 7 genes homologous to genes related to the magnetosomes synthesis. To assess the question of the biological function of this genomic islet, we further investigated the role of one of the seven genes, mamK-like. Filaments were observed in E. coli cells expressing MamK-like-Venus fusion by fluorescence microscopy. In vitro polymerization of both isoforms is comparable, though some differences are present at the structural level. In addition, we demonstrate that mamK-like is transcribed in AMB-1 wild-type and ΔmamK mutant cells. Immunolabelling assay using an anti-MamK antibody reveals the presence of a filament in the ΔmamK mutant. We hypothesise that this filament is due to MamK-like and that it helps maintaining a chain-like organisation of magnetosomes in the mutant strain.

A moesina, uma das proteínas do complexo ERM (ezrina, radixina e moesina), está envolvida nos processos de migração e invasão tumoral, participando da dinâmica do citoesqueleto na movimentação celular associada à ativação da GTPase Rho-A. O objetivo desse estudo foi avaliar a correlação da imunoexpressão da moesina e da Rho-A em tumores odontogênicos benignos, diagnosticados no Serviço de Anatomia Patológica da Faculdade de Odontologia de Bauru (USP), no período de 1963 a 2009. Um total de 45 tumores odontogênicos benignos incluindo 7 ameloblastomas, 8 tumores odontogênicos adenomatóides, 19 tumores odontogênicos queratocísticos, 2 cistos odontogênicos ortoqueratinizantes, 1 tumor odontogênico epitelial calcificante, 2 fibromas ameloblásticos, 4 fiboodontomas ameloblásticos e 2 tumores odontogênicos císticos calcificantes, foram avaliados quanto a expressão imunohistoquímica da moesina e da Rho-A pelas células odontogênicas. A correlação entre as expressões membranosa e citoplasmática da moesina e da Rho-A pelo epitélio odontogênico nos diferentes tumores foi avaliada pelo teste de correlação de Spearman, com nível de significância de 5%. Os resultados mostraram uma forte expressão membranosa de moesina e citoplasmática de Rho-A em 66,7% e 62,2% dos tumores odontogênicos benignos, respectivamente. Houve uma correlação positiva e estatisticamente significativa entre a expressão membranosa e citoplasmática da moesina (ρ=0,000) e de Rho-A (ρ=0,048) nos tumores. Entretanto, não houve correlação entre as expressões demoesina e de Rho-A nos tumores odontogênicos benignos. Estes resultados comprovam que a moesina e a Rho-A são fortemente expressas pelo epitélio odontogênico neoplásico e, sugerem que ambas proteínas provavelmente participamdo crescimento e expansão local destes tumores odontogênicos benignos. / The moesin, one of the proteins of the ERM complex (ezrin, radixin and moesin), is involved in the migration and tumor invasion processes participating in the cytoskeleton dynamics in cell movement associated with the activation of the GTPase Rho-A. The aim of this study was to evaluate the immunoexpression orrelation of moesin and Rho-A in benign odontogenic tumors, diagnosed at the Bauru School of Dentistry Oral Pathology Biopsy Service of the University of São Paulo in the period of 1963-2009. A total of 45 benign odontogenic tumors including 7 ameloblastomas, 8 adenomatoid odontogenic tumors, 19 keratocystic odontogenic tumors, 2 orthokeratinized odontogenic cyst, 1 calcifying epithelial odontogenic tumor, 2 ameloblastic fibroma, 4 ameloblastic fibroodontoma and 2 calcifying cystic odontogenic tumors, were evaluated for immunohistochemical expression of moesin and Rho-A by odontogenic cells. The correlation between the membranous and cytoplasmic expression of moesin and Rho-A by the odontogenic epithelium in different tumors was evaluated by the Spearman correlation test, with a significance level of 5%. The results showed strong membranous expression of moesin and cytoplasmic expression of Rho-A in 66.7% and 62.2% of the benign odontogenic tumors, respectively. There was a positive and statistically significant correlation between membranous and cytoplasmic expression of moesin (ρ=0.000) and Rho-A (ρ=0.048) in the tumors. However, there was no correlation between the expression of moesin and Rho-A in benign odontogenic tumors. These results show that the moesin and Rho-A are strongly expressed by neoplastic odontogenic epithelium and suggest that both proteins probably participate in the growth and local expansion of these benign odontogenic tumors.

No útero gestante dos animais com placentação do tipo hemocorial, ocorre uma migração e acúmulo transitório de linfócitos natural killer (NK) , cuja atuação na gestação não está totalmente elucidada. Estas células NK do ambiente uterino (uNK) apresentam comportamento distinto daquelas encontradas no sangue circulante (cNK), constituindo uma sub-população das células NK com expressão gênica específica ditada pelo ambiente uterino gestante. De fato, se estas células isoladas do útero de camundongos prenhes forem inoculadas em machos da mesma espécie eram capazes de induzir a resposta imunológica com produção de anticorpos que reagem especificamente com as células uNK. No presente trabalho foi utilizado um destes anticorpos monoclonais denominados de \"mouse anti-mouse uterine natural killer cell clone 1 (mam-uNK1)\" obtidos anteriormente em nosso laboratório para avaliar a especificidade deste anticorpo e a localização da molécula antigênica correspondente. Para tanto, foram utilizados cortes histológicos do útero no 9º dia de gestação, dos órgãos linfóides (baço, timo e linfonodo), do cérebro, do fígado e do coração submetidos à reações imunocitoquímicas com o anticorpo mam-uNK1 em nível da microscopia de luz e, pela imunomicroscopia eletrônica nas células uNK do útero gestante e células estriadas cardíacas do miocárdio. Foram obtidos homogenados teciduais dos mesmos órgãos avaliados pela imunocitoquímica para realização do SDS-PAGE e Western-blot com o intuído de identificar as frações protéicas reativas e homologia entre os diversos órgãos. Os padrões de imunomarcação com o mam-uNK1 foram comparadas com o padrão de reatividade da lectina DBA (Dolichos biflorus) tanto nos cortes histológicos quanto nos homogenados submetidos ao Western-blot. Os resultados demonstraram reação positiva distribuída difusamente no citoplasma, com maior intensidade no perímetro das células uNK, e marcação difusa no citoplasma das células deciduais e das células musculares lisas do miométrio. Reações positivas foram encontradas também no citoplasma das células musculares cardíacas, no citoplasma das células reticulares dos órgãos linfóides, nos feixes de nervos do sistema nervoso central e no citoplasma dos hepatócitos. Pela imunomicroscopia eletrônica foram observadas partículas de ouro coloidal em maior número no citoplasma que preenchem os prolongamentos citoplasmáticos tipo microvilosidades e no citoplasma marginal abaixo da membrana plasmática nas células uNK. Nas células musculares cardíacas as marcações mais intensas foram constatadas no citoplasma da extremidade destas células onde as miofibrilas eram menos organizadas e se ancoravam à membrana plasmática. Pelo Western-blot, foram identificadas duas bandas reativas ao mam-uNK1 com peso molecular de 52 e 54 kDa comuns a todos os órgãos analisados. Estes dados demonstram que a molécula reconhecida pelo anticorpo mam-uNK1 tem ampla distribuição em diversos tipos celulares não sendo específica para as células uNK, porém apresentam uma localização peculiar nestas células e nas células musculares cardíacas. Pelo padrão de localização identificado em imunomicroscopia eletrônica, presume-se que estas moléculas estejam associadas com a modulação do citoesqueleto nas diversas atividades que estes componentes estruturais desempenham nas células, sendo particularmente interessante a relação com a motilidade celular. / In the pregnant uterus of animals developing hemochorial type placentation occurs a transient migration and accumulation of natural killer lymphocytes (NK) which activity in the pregnancy has not been fully elucidated. These NK cells from uterine environment (uNK) present a distinct behavior from those found in the peripheral circulating blood (cNK), composing a subset of NK cells with specific gene expression that is regulated by pregnant uterus. Actually, these cells isolated from pregnant mice uteri were inoculated in the male mice of same strains, they induced immune response with production of antibodies reactivity specifically to uNK cells. In the present work it was used one of these mouse anti-mouse uterine natural killer cells clone 1 (mam-uNK1) monoclonal antibody that was obtained previously in our laboratory, in the aim to evaluate the specificity of this antibody and localization of corresponding antigenic molecule. It was used histological sections of uteri on 9º gestational day, lymphoid organs (spleen, thymus and lymph node), brain, liver and heart processed for immunocytochemistry with mam-uNK antibody at light microscopy and immunoelectron microscopy for uNK cells in pregnant uterus and cardiac muscle cells. Tissue homogenates from the same organs that were evaluated by immunocytochemistry were obtained to perform SDS-PAGE and Western-blot primary to identify the proteins fractions reactive with mam-uNK antibody and possible homology among the tissues. The immunolabeling pattern using mam-uNK both, in histological sections and Western-blot were compared with pattern of Dolichos biflorus (DBA) lectin reactions. The results showed diffuse positive reaction distributed in the cytoplasm with higher intensity on perimeter of uNK cells and diffuse labeling in the cytoplasm of decidual cells and, in smooth muscle cells of miometrium. Positive reaction was also found in the cytoplasm of cardiac muscle cells, reticular cells of lymphoid organs, hepatocytes and in the axon bundles of the brain. By immunelectron microscopy, were observed higher number of gold particles in the cytoplasm of microvillous-like cell processes and in the marginal cytoplasm near the plasma membrane of uNK cells. In the cardiac muscle cells the most conspicuous labeling was seen in the cytoplasm of muscle cells at the end portions, that is, where the myofibrills were less organized and anchoring to plasma membrane. The Western-blot identified two bands with 52 and 54 kDa reactive do mam-uNK constantly found in all organs analyzed. These data show that the molecule that is recognized by mam-uNK1 antibody is widely distributed in several cell types, not specific for mouse uNK cells, but has a very peculiar localization in these cells and in the cardiac muscle cells. To the localization pattern that was identified by immunelectron microscopy it was suggested that, these molecules were associated to the modulation of the cytoskeleton in many activities that these structural component potentially could carry out in the cells, being particularly attractive those related to cell motility.