Actin in migrating cells is regulated by Rho GTPases. However, Rho proteins might also affect microtubules (MTs). Here, we used time-lapse microscopy of PtK1 cells to examine MT regulation downstream of Rac1. In these cells, "pioneer" MTs growing into leading-edge protrusions exhibited a decreased catastrophe frequency and an increased time in growth as compared with MTs further from the leading edge. Constitutively active Rac1(Q61L) promoted pioneer behavior in most MTs, whereas dominant-negative Rac1(T17N) eliminated pioneer MTs, indicating that Rac1 is a regulator of MT dynamics in vivo. Rac1(Q61L) also enhanced MT turnover through stimulation of MT retrograde flow and breakage. Inhibition of p21-activated kinases (Paks), downstream effectors of Rac1, inhibited Rac1(Q61L)-induced MT growth and retrograde flow. In addition, Rac1(Q61L) promoted lamellipodial actin polymerization and Pak-dependent retrograde flow. Together, these results indicate coordinated regulation of the two cytoskeletal systems in the leading edge of migrating cells.
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http://dx.doi.org/10.1083/jcb.200303082 | DOI Listing |
Int J Mol Sci
December 2024
Joint International Research Laboratory of Information Display and Visualization, School of Electronic Science and Engineering, Southeast University, Nanjing 210096, China.
This study presents a facile one-pot synthesis method to fabricate BiFeO-BiFeO-BiO heterojunction photocatalysts with controllable compositions and pure phases. Three different binary heterojunctions (BiFeO/BiFeO, BiFeO/BiO, and BiFeO/BiO) and a ternary BiFeO/BiFeO/BiO heterojunction were formed, all exhibiting significantly enhanced photocatalytic performance for the degradation of methylene blue (MB) and phenol under visible light irradiation, outperforming the individual compositions. Notably, the BiFeO/BiFeO heterojunction achieved the highest degradation efficiency (93.
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December 2024
Faculty of Civil Engineering and Mechanics, Kunming University of Science and Technology, Kunming 650500, China.
The failure mode of thin-walled C-channel beams typically manifests as premature local buckling of the compression flange, leading to insufficient utilization of material strength in both the flange and the web. To address this issue, this study adopts the approach of increasing the number of bends to reinforce the flange and adding V-shaped stiffeners in the middle of the web to reduce the width-to-thickness ratio of the plate elements, thereby delaying local buckling and allowing for greater plastic deformation. However, the challenge lies in the irregular cross-sectional shape and complex buckling patterns.
View Article and Find Full Text PDFDiagnostics (Basel)
December 2024
Department of Information Technology, Aylol University College, Yarim 547, Yemen.
Background: Neurodegenerative diseases (NGD) encompass a range of progressive neurological conditions, such as Alzheimer's disease (AD) and Parkinson's disease (PD), characterised by the gradual deterioration of neuronal structure and function. This degeneration manifests as cognitive decline, movement impairment, and dementia. Our focus in this investigation is on PD, a neurodegenerative disorder characterized by the loss of dopamine-producing neurons in the brain, leading to motor disturbances.
View Article and Find Full Text PDFJpn J Radiol
January 2025
Department of Oncology-Pathology, Karolinska Institutet, Solna, Sweden.
Artificial intelligence (AI) has emerged as a transformative tool in breast cancer screening, with two distinct applications: computer-aided cancer detection (CAD) and risk prediction. While AI CAD systems are slowly finding its way into clinical practice to assist radiologists or make independent reads, this review focuses on AI risk models, which aim to predict a patient's likelihood of being diagnosed with breast cancer within a few years after negative screening. Unlike AI CAD systems, AI risk models are mainly explored in research settings without widespread clinical adoption.
View Article and Find Full Text PDFTrends Biotechnol
January 2025
School of Environment and Energy Engineering, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea; Research Center for Innovative Energy and Carbon Optimized Synthesis for Chemicals, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea. Electronic address:
(Homo)acetogens, including Clostridium spp., represent an enigma in metabolic flexibility and diversity. Eubacterium callanderi KIST612 is an acetogen that produces n-butyrate with carbon monoxide (CO) as the carbon and energy source; however, the production route is unknown.
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