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The mitotic spindle is the bipolar, microtubule-based structure that segregates chromosomes at each cell division. Aberrant spindles are frequently observed in cancer cells, but how oncogenic transformation affects spindle mechanics and function, particularly in the mechanical context of solid tumors, remains poorly understood. Here, we constitutively overexpress the oncogene cyclin D1 in human MCF10A cells to probe its effects on spindle architecture and response to compressive force. We find that cyclin D1 overexpression increases the incidence of spindles with extra poles, centrioles, and chromosomes. However, it also protects spindle poles from fracturing under compressive force, a deleterious outcome linked to multipolar cell divisions. Our findings suggest that cyclin D1 overexpression may adapt cells to increased compressive stress, contributing to its prevalence in cancers such as breast cancer by allowing continued proliferation in mechanically challenging environments.

The kinesin-3 motor KIF13B functions in endocytosis, vesicle transport and regulation of ciliary length and signaling. Direct binding of the membrane-associated guanylate kinase (MAGUK) DLG1 to the MAGUK-binding stalk domain of KIF13B relieves motor autoinhibition and promotes microtubule plus-end-directed cargo transport. Here, we characterize angiomotin (AMOT) isoform 2 (p80, referred to as Ap80) as a novel KIF13B interactor that promotes binding of another MAGUK, the polarity protein and Crumbs complex component PALS1, to KIF13B. Live-cell imaging analysis indicated that Ap80 is concentrated at and recruits PALS1 to the base of the primary cilium, but is not a cargo of KIF13B itself. Consistent with a ciliary function for Ap80, its depletion led to elongated primary cilia and reduced agonist-induced ciliary accumulation of SMO, a key component of the Hedgehog signaling pathway, whereas Ap80 overexpression caused ciliary shortening. Our results suggest that Ap80 activates KIF13B cargo binding at the base of the primary cilium to regulate ciliary length, composition and signaling. Ministry of Education (MOE) Published version This work was supported by grants from Novo Nordisk Fonden (NNF14OC0011535, NNF15OC0016886), Hartmann Fonden (A31662), Kræftens Bekæmpelse (R146- A9590), Københavns Universitet (University of Copenhagen, UCPH) Excellence Programme for Interdisciplinary Research to L.B.P. and S.T.C., the Danmarks Frie Forskningsfond (6108-00457B) to S.T.C. and the Ministry of Education - Singapore (MOE 2019-T1-002-097) to A.L. S.K.M. was partially supported by a PhD fellowship from the Department of Biology, Københavns Universitet. A.A. was supported by the Netherlands X-omics Initiative partially funded by Nederlandse Organisatie voor Wetenschappelijk Onderzoek (project 184.034.019).

The kinesin-3 motor KIF13B functions in endocytosis, vesicle transport, and regulation of ciliary length and signaling. Direct binding of the membrane-associated guanylate kinase (MAGUK) DLG1 to KIF13B’s MAGUK-binding stalk (MBS) domain relieves motor autoinhibition and promotes microtubule plus end-directed cargo transport. Here we characterize Angiomotin isoform 2 (Ap80) as a novel KIF13B interactor that promotes binding of another MAGUK, the polarity protein and Crumbs complex component PALS1, to KIF13B. Live cell imaging analysis indicated that Ap80 is concentrated at the base of primary cilia and recruits PALS1 to this site, but is not itself a cargo of KIF13B. Consistent with a ciliary function for Ap80, its depletion led to elongated primary cilia while its overexpression caused ciliary shortening. Our results suggest that Ap80 may specifically activate KIF13B cargo binding at the base of primary cilia to regulate ciliary length.

Sustainability is a topic of interest to science and organizations, an emerging research area in the agrifood field and business management. This area aims to investigate the processes that lead organizations to sustainability and those that lead to organizational learning and the consequent continuous improvement. This work seeks to understand the evolution and trend of studies on the sustainability of the rice value chain. In this sense, a bibliometric review of the literature in the Scopus database was carried out as a methodological procedure, in the years 2001 to 2021, to observe the publications on the theme of sustainability of the rice value chain existing over the 20 years of this century. Among the results obtained, it was verified that the publications on the topic addressed had an exponential growth from the year 2015, that is, from 80 publications to more than 400 in 2019, and it can be observed that this theme has become of due importance, with a view to sustainability. As an essential result of this study, it is observed that in 2019 there were more than 200 publications on the theme of rice sustainability. All of this leads to the belief that there is an interest on the part of researchers and authors to deepen their research questions in this area, with different approaches to understand the value chain and the sustainability of rice. La sostenibilidad es un tema de interés para la ciencia y las organizaciones, un área de investigación emergente en el campo agroalimentario y la gestión empresarial. Esta área tiene como objetivo investigar los procesos que llevan a las organizaciones a la sostenibilidad y los que conducen al aprendizaje organizacional y la consecuente mejora continua. Este trabajo busca comprender la evolución y tendencia de los estudios sobre la sostenibilidad de la cadena de valor del arroz. En este sentido, se realizó una revisión bibliométrica de la literatura en la base de datos Scopus como procedimiento metodológico, en los años 2001 al 2021, para observar las publicaciones sobre el tema de la sostenibilidad de la cadena de valor del arroz existentes a lo largo de los 20 años de este. siglo. Entre los resultados obtenidos, se verificó que las publicaciones sobre el tema abordado tuvieron un crecimiento exponencial desde el año 2015, es decir, de 80 publicaciones a más de 400 en 2019, y se puede observar que este tema ha cobrado la debida importancia. , con miras a la sostenibilidad. Como resultado esencial de este estudio, se observa que en 2019 hubo más de 200 publicaciones sobre el tema de la sostenibilidad del arroz. Todo esto lleva a pensar que existe un interés por parte de investigadores y autores por profundizar sus preguntas de investigación en esta área, con diferentes enfoques para entender la cadena de valor y la sostenibilidad del arroz. A sustentabilidade é um tema de interesse da ciência e das organizações, sendo uma área de pesquisa emergente no campo agroalimentar e gestão empresarial. Esta área objetiva a investigação dos processos que conduzem as organizações à sustentabilidade, bem como àqueles que conduzem à aprendizagem organizacional e a consequente melhoria contínua. O objetivo deste trabalho é conhecer a evolução e tendência dos estudos sobre a sustentabilidade da cadeia de valor do arroz. Neste sentido, realizou-se como procedimento metodológico uma revisão bibliométrica da literatura no banco de dados Scopus, nos anos de 2001 a 2021, pretendendo-se com isto observar as publicações com o tema sustentabilidade da cadeia de valor do arroz existentes no decorrer dos 20 anos deste século. Dentre os resultados obtidos, verificou-se as publicações sobre o tema abordado tiveram um crescimento exponencial a partir do ano de 2015, ou seja, de 80 publicações para mais de 400 em 2019, podendo-se observar que tal tema passou a ter a devida importância, com vistas à sustentabilidade. Como resultado importante deste estudo observa-se que no ano de 2019 houve mais de 200 publicações com o tema sustentabilidade do arroz. Tudo isso leva a crer que há interesse por parte dos pesquisadores e autores em aprofundar suas questões de pesquisa nesta área, com abordagens diversas com a finalidade do conhecimento da cadeia de valor e a sustentabilidade do arroz.

NuMA disruption causes nuclear defects, and it was unclear if this is due to NuMA's essential spindle function. Serra-Marques et al. show that NuMA keeps chromosomes together at nuclear formation and promotes a mechanically robust nucleus independently of its spindle function., Eukaryotic cells typically form a single, round nucleus after mitosis, and failures to do so can compromise genomic integrity. How mammalian cells form such a nucleus remains incompletely understood. NuMA is a spindle protein whose disruption results in nuclear fragmentation. What role NuMA plays in nuclear integrity, and whether its perceived role stems from its spindle function, are unclear. Here, we use live imaging to demonstrate that NuMA plays a spindle-independent role in forming a single, round nucleus. NuMA keeps the decondensing chromosome mass compact at mitotic exit and promotes a mechanically robust nucleus. NuMA’s C terminus binds DNA in vitro and chromosomes in interphase, while its coiled-coil acts as a central regulatory and structural element: it prevents NuMA from binding chromosomes at mitosis, regulates its nuclear mobility, and is essential for nuclear formation. Thus, NuMA plays a structural role over the cell cycle, building and maintaining the spindle and nucleus, two of the cell’s largest structures.

Intracellular transport relies on different types of kinesins, but it is poorly understood which kinesins are present on a particular cargo, what their specific roles are and whether they can act simultaneously on the same cargo. Here, we show that Rab6-positive secretory vesicles are transported from the Golgi apparatus to the cell periphery by kinesin-1 KIF5B and kinesin-3 KIF13B, which determine the location of secretion events. KIF5B plays a dominant role, whereas KIF13B helps Rab6 vesicles to reach freshly polymerized microtubule ends, to which KIF5B binds poorly, likely because its cofactors, MAP7-family proteins, are slow in populating these ends. Sub-pixel localization demonstrated that during microtubule plus-end directed transport, both kinesins localize to the vesicle front and can be engaged on the same vesicle. When vesicles reverse direction, KIF13B relocates to the middle of the vesicle, while KIF5B shifts to the back, suggesting that KIF5B but not KIF13B undergoes a tug-of-war with a minus-end directed motor.

Intracellular transport relies on multiple kinesins, but it is poorly understood which kinesins are present on particular cargos, what their contributions are and whether they act simultaneously on the same cargo. Here, we show that Rab6-positive secretory vesicles are transported from the Golgi apparatus to the cell periphery by kinesin-1 KIF5B and kinesin-3 KIF13B, which determine the location of secretion events. KIF5B plays a dominant role, whereas KIF13B helps Rab6 vesicles to reach freshly polymerized microtubule ends, to which KIF5B binds poorly, likely because its cofactors, MAP7-family proteins, are slow in populating these ends. Sub-pixel localization demonstrated that during microtubule plus-end directed transport, both kinesins localize to the vesicle front and can be engaged on the same vesicle. When vesicles reverse direction, KIF13B relocates to the middle of the vesicle, while KIF5B shifts to the back, suggesting that KIF5B but not KIF13B undergoes a tug-of-war with a minus-end directed motor.

Os aços de alta resistência e baixa liga são amplamente utilizados em dutos transportadores de óleo e gás e, atualmente, o desenvolvimento de novos projetos de liga e o uso de técnicas altamente avançadas de fabricação e processamento dos aços se tornaram essenciais para obtenção de estruturas que resistam aos danos provocados por H, principal motivo de falha de oleodutos e gasodutos em meios ricos em H2S. No presente trabalho, avaliou-se o efeito de características microestruturais na difusividade do H em dois aços grau API X65, com diferentes teores de Mn. Uma das chapas ainda está em fase experimental de desenvolvimento, tem baixo teor de Mn e foi produzida para aplicação em ambientes sour. A outra chapa tem alto teor de Mn, já é usada comercialmente há alguns anos e foi desenvolvida para trabalho em ambientes doces. Os dois materiais passaram por caracterização microestrutural nas três seções da chapa: longitudinal e transversal à direção de laminação e do topo da chapa (paralela à direção de laminação). Após a caracterização, amostras de cada seção dos aços foram submetidas a ensaios de permeabilidade ao H; o aço baixo Mn passou por análises de EBSD (Difração de Elétrons Retroespalhados), para determinação de textura. O aço baixo Mn tem microestrutura homogênea ao longo da espessura da chapa, composta por ferrita refinada e pequenas ilhas de perlita. O aço alto Mn, por sua vez, apresenta microestrutura heterogênea ao longo da espessura, formada por bandas de ferrita e perlita, com marcada presença de segregação central de elementos de liga. Os ensaios de permeabilidade ao H mostraram que os coeficientes de difusão efetiva do H, Deff, do aço baixo Mn são ligeiramente superiores aos do aço alto Mn. Outros dois importantes parâmetros que foram calculados para os dois aços são a concentração de H na sub-superfície do material, C0, e o número de traps por unidade de volume, Nt. Contrariando expectativas, o aço baixo Mn apresentou maiores valores de C0 e Nt do que o aço alto Mn. Ensaios preliminares de dessorção térmica realizados nos dois aços mostraram os mesmos resultados: o aço baixo Mn aprisiona mais H do que o aço alto Mn. Estes resultados contraditórios de C0 e Nt foram atribuídos à presença de nanoprecipitados de microadições de liga no aço baixo Mn, não detectáveis por microscopia óptica e eletrônica de varredura. Ainda, para os dois aços, os valores de Deff variaram em função da seção analisada da seguinte maneira: Deff longitudinal ? Deff transversal > Deff topo. Para entender melhor o comportamento anisotrópico da difusão do H nos dois aços calculou-se um novo coeficiente de difusão, que foi chamado de coeficiente de difusão no estado estacionário, Dss. O Dss considera que todos os traps do aço estão saturados, permitindo, assim que se avalie somente o efeito de obstáculos físicos à difusão do H. No aço alto Mn, o Dss variou da mesma maneira que o Deff: Dss longitudinal ? Dss transversal > Dss topo; este comportamento foi atribuído ao bandeamento presente no material. No aço baixo Mn, o Dss variou de forma diferente do Deff: Dss transversal > Dss longitudinal >= Dss topo, indicando que a difusão do H pode ser auxiliada por contornos de grão enquanto os traps estão sendo saturados, e que a textura cristalográfica pode influenciar a difusão após o estado estacionário ser atingido. High strength low alloy steels are widely applied as pipelines for crude oil and natural gas transportation and, currently, new approaches to alloy design, in addition to the use of advanced steelmaking and processing techniques, have become essential for obtaining structures that resist to hydrogen damage, which is the main cause of pipelines failure in H2S-rich environments. The main objective of the present work is to evaluate the influence of microstructural features on hydrogen diffusivity in two API X65 steels, with different Mn contents. One of the steel plates has been recently developed for usage in sour environments, is on its experimental stage and has a low Mn content. The other one is a commercial plate steel, with high Mn content, developed for sweet applications. Both steel plates were characterized in its three sections, in relation to the rolling direction: longitudinal, transverse and top surface of the plate (parallell to the rolling direction). After that, samples obtained from each section of the plates were submitted to hydrogen permeation tests; the low Mn steel was also analysed with EBSD, for texture determination. The low Mn steel presents a homogeneous microstructure through plate thickness, composed of refined ferrite and small pearlite islands. The high Mn steel has a heterogeneous microstructure through the plate thickness, composed of ferrite and pearlite bands, and presents centerline segregation. Hydrogen permeation tests showed that the Deff obtained for the low Mn steel sections are slightly higher than for the high Mn steel. Another two important parameters that were calculated for both steels are the subsurface hydrogen concentration, C0, and the number of traps per unit volume, Nt. Contrary to what was expected, the low Mn steel presented the higher C0 and Nt values. Thermal dessorption spectroscopy analysis confirmed that the low Mn steel traps more H atoms than the high Mn one. These results, along with the similar Deff values, were related to the presence of nanoprecipitates of microalloying elements, that cannot be detected via optical and scanning electron microscopy. Additionally, also for both steels, the Deff values varied in function of the analyzed section as it follows: Deff longitudinal ? Deff transverse > Deff top. In order to better understand this anisotropic behavior, a new diffusion coefficient, which was called diffusion coefficient at the steady state, Dss, was determined. Dss considers that all the trapping sites are saturated, enabling, thus, the evaluation of physical obstacles to H diffusion. For the high Mn steel, the Dss varied in the same matter as the Deff: Dss longitudinal ? Dss transverse > Dss top; this behavior was associated with the microstructural banding present in the material. For the low Mn steel, the Dss exhibited a different behavior: Dss transverse > Dss longitudinal >= Dss top, suggesting that H diffusion can be aided by grain boundaries while the trapping sites are being filled and that crystallographic texture may play its role after the steady state is reached.

The paper compares Hydrogen Induced Cracking (HIC) resistance and Hydrogen Permeation (HP) results for two API X65 microalloyed steels, with different contents of Mn and Nb: one containing low Mn and high Nb (L-Mn) and the other, high Mn and low Nb (H-Mn). The main objective is to correlate the microstructural differences between these steels with hydrogen diffusion and trapping behavior and hydrogen-induced cracking resistance. Both steel plates were characterized with optical and scanning electron microscopy in their transverse sections, in relation to the rolling direction. HIC resistance tests were made in accordance with the NACE TM0284-11 standard; samples obtained from the transverse section were also submitted to Hydrogen Permeation tests, based on the ASTM G148-97 standard. NACE solution A saturated with H2S was used in the two procedures. Besides, Thermal Desorption Spectroscopy measurements were made, in order to show which steel trapped more hydrogen atoms, and carbides/carbonitrides volume fractions were estimated with ThermoCalc software. The L-Mn steel presents a homogeneous microstructure through the plate thickness, composed of refined ferrite and small pearlite islands. The H-Mn steel has a heterogeneous microstructure through the plate thickness, composed of ferrite and pearlite bands, and presents centerline segregation. Hydrogen permeation tests showed that, despite all the microstructural differences, the hydrogen effective diffusion coefficient (Deff) was almost the same for both steels – the Deff obtained for the L-Mn steel is slightly higher than for the H-Mn steel. Contrary to expectations, the L-Mn steel presented higher hydrogen subsurface concentration (C0) and number of trapping sites per unit volume (Nt) values. Thermal Desorption Spectroscopy analysis confirmed that the L-Mn steel traps more H atoms than the H-Mn one. These results, along with the similar Deff values, can be explained by the presence of nanoprecipitates of microalloying elements, which, according to ThermoCalc simulations, appear in higher volume fraction in the L-Mn steel. Finally, the HIC tests results showed that the L-Mn steel has a better performance in sour environments; this behaviour is related with its special microstructural features.

Die-cast AZ91D magnesium alloy samples have been submitted for anodizing at different potentials. Anodizing was conducted in an environmentally friendly solution which comprised 3 M KOH + 1 M Na2SiO3 at room temperature. The surface treatment was performed electrolytically at four different potentials: 3, 5, 8, and 10 V. The corrosion resistance was evaluated by electrochemical impedance spectroscopy and potentiodynamic polarization curves obtained after 7 days of immersion in a 3.5 wt.% NaCl solution at room temperature. The porosity of the anodic films was estimated by means of the linear polarization method. SEM images revealed that the surface oxide was thicker for the anodic films obtained at 3 and 5 V. The films obtained at these potentials were more porous than those formed at 8 and 10 V. The results showed that the thickness of the anodic film had a significant effect on the corrosion behavior of the AZ91D, whereas the influence of the initial porosity was not significant.

The corrosion resistance and semiconducting properties of the oxide film formed on the AZ91D alloy were evaluated. The alloy was tested in the as-cast condition and after a solution annealing treatment. Electrochemical impedance spectroscopy measurements and potentiodynamic polarization curves were obtained in a H3BO3 (0.05 M) + Na2B4O7⋅10H2O (0.075 M) solution with pH = 9.2 at room temperature. The semiconducting properties of the oxide film were evaluated using Mott–Schottky plots. The corrosion resistance of the AZ91D was reduced after the solution treatment while the semiconducting properties of the passive films were little affected.

This study dissects the recruitment of dynein and dynactin to cargo by a conserved motor adaptor BICD2. It is shown that dynein, dynactin, and BICD2 form a triple complex in vitro and in vivo. Investigation of the properties of this complex by direct visualization of dynein in live cells shows that BICD2-induced dynein transport requires LIS1., Cytoplasmic dynein is the major microtubule minus-end–directed cellular motor. Most dynein activities require dynactin, but the mechanisms regulating cargo-dependent dynein–dynactin interaction are poorly understood. In this study, we focus on dynein–dynactin recruitment to cargo by the conserved motor adaptor Bicaudal D2 (BICD2). We show that dynein and dynactin depend on each other for BICD2-mediated targeting to cargo and that BICD2 N-terminus (BICD2-N) strongly promotes stable interaction between dynein and dynactin both in vitro and in vivo. Direct visualization of dynein in live cells indicates that by itself the triple BICD2-N–dynein–dynactin complex is unable to interact with either cargo or microtubules. However, tethering of BICD2-N to different membranes promotes their microtubule minus-end–directed motility. We further show that LIS1 is required for dynein-mediated transport induced by membrane tethering of BICD2-N and that LIS1 contributes to dynein accumulation at microtubule plus ends and BICD2-positive cellular structures. Our results demonstrate that dynein recruitment to cargo requires concerted action of multiple dynein cofactors.

Intracellular transport along cytoskeletal filaments is an essential cellular process that controls numerous cellular functions by promoting correct sorting, transport and delivery of different cargos in the cell. The microtubule system and associated molecular motors, dynein and kinesins, are essential components of this process, and their tight regulation is required to ensure the precise spatio-temporal distribution of cargos. In this thesis, we dissect the mechanisms underlying cargo selection and cargo transport by microtubule motors and adaptor proteins and investigate possible connections between the docking and fusion machineries essential for the delivery of cellular content into the extracellular space. In chapter 1, we introduce molecular motors and focus on the current knowledge on the organization of microtubule-based transport. The role of adaptor proteins in controlling cargo selection and motor activity is investigated in chapter 2, where we demonstrate that the adaptor protein BICD2 forms a triple complex with the dynein-dynactin complex and promotes a stable interaction between dynein and dynactin. Additionally, we provide evidence for the requirement of this triple stable complex for dynein activation and show that the interaction between dynein, dynactin and LIS1 is required for the BICD2-mediated recruitment of the dynein complex to cellular structures. In chapter 3, we investigate the role of different kinesins and adaptor proteins in the transport of Rab6-positive secretory vesicles. We demonstrate that kinesin-1 and kinesin-3 differently influence the speed of transport of Rab6 vesicles. Additionally, we demonstrate that the Bicaudal D family proteins BICD2 and BICDR-1 differentially regulate the velocity of dynein-based movements. We show that BICDR-1 increases the velocity of transport of secretory vesicles towards microtubule minus ends and thereby controls the distribution of cellular cargos. In chapter 4, we show that kinesin-3 family member KIF13B promotes the transport of constitutive secretory vesicles to the periphery of the cell. Additionally, we analyze the distribution of KIF13B on single Rab6 vesicles during active transport, a promising system to study multimotor transport mechanisms in the context of the cell. In chapter 5, we demonstrate that KIDINS220, a novel KIF13B-interacting protein, links KIF13B to the Dystrophin-Associated Protein Complex (DAPC) and provide evidence for the presence of this complex at cortical structures in proximity of focal adhesions. Based on these results, we discuss the possible role for the KIF13B-DAPC complex in podosomes and neurons. In chapter 6, we investigate the molecular link between the docking and fusion machineries for Rab6 vesicles. We found that the SNARE proteins VAMP4 and SNAP29 are involved in the fusion of Rab6 vesicles with the plasma membrane. Additionally, we propose a new function for the EHD endocytic family in the exocytosis of carriers of constitutive secretion. In chapter 7, we discuss the general implications of our findings and the possible strategies for future experiments.