Discussions of actin cell biology generally focus on the cortex, a thin, actin-rich layer of cytoplasm under the plasma membrane. Here we review the much less studied biology of actin filaments deeper in the cytoplasm and their recently revealed functions in mitosis and meiosis that are most prominent in large oocyte, egg and early embryo cells. The cellular functions of cytoplasmic actin range from the assembly and positioning of meiotic spindles to the prevention of cytoplasmic streaming. We discuss the possible use of evolutionarily conserved mechanisms to nucleate and organize actin filaments to achieve these diverse cellular functions, the cell-cycle regulation of these functions, and the many unanswered questions about this largely unexplored mechanism of cytoplasmic organization.
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http://dx.doi.org/10.1016/j.cub.2011.07.043 | DOI Listing |
Gene
January 2025
College of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang 212100 China; Sericulture Research Institute, Chinese Academy of Agricultural Sciences, Zhenjiang 212100 China. Electronic address:
Nosema bombycis, the causative agent of pebrine disease, poses a significant threat to the silkworm industry due to its negative impact on silkworm health and productivity. The chaperonin-containing tailless complex polypeptide (CCT) plays a crucial role in protein folding, and its β subunit (CCTβ) is essential for the proper folding of cytoskeletal proteins, such as actin and tubulin. In this study, we cloned and expressed the NbCCTβ gene from N.
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January 2025
Molecular Microbiology, School of Biosciences, University of Sheffield, Sheffield S10 2TN, UK. Electronic address:
The core component of the actin cytoskeleton is the globular protein G-actin, which reversibly polymerizes into filaments (F-actin). Budding yeast possesses a single actin that shares 87%-89% sequence identity with vertebrate actin isoforms. Previous structural studies indicate very close overlap of main-chain backbones.
View Article and Find Full Text PDFCells
January 2025
Biotech Research and Innovation Center (BRIC), University of Copenhagen, Ole Maaløes Vej5, 2200 Copenhagen, Denmark.
Nuclear actin polymerization was reported to control different nuclear processes, but its regulation is poorly understood. Here, we show that N-WASP can trigger the formation of nuclear N-WASP/F-actin nodules. While a cancer hotspot mutant of N-WASP lacking the VCA domain (V418fs) had a dominant negative function on nuclear F-actin, an even shorter truncation mutant found in melanoma (R128*) strongly promoted nuclear actin polymerization.
View Article and Find Full Text PDFFood Res Int
January 2025
State Key Laboratory of Food Science and Resources, National Engineering Research Center of Cereal Fermentation and Food Biomanufacturing, School of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu 214122, China; Guangdong Engineering Research Center of High-Value Utilization and Equipment Development of Marine Biological Resources, Southern Marine Science and Engineering Guangdong Laboratory, Guangzhou, Guangdong 511458, China; Jiangnan University (Shaoxing) Industrial Technology Research Institute, Shaoxing, Zhejiang 31200, China; National Engineering Research Center of Huangjiu, Zhejiang Guyuelongshan Shaoxing Wine CO., LTD, Shaoxing 646000, Zhejiang, China. Electronic address:
To explore the mechanism of Virgibacillus proteases on hydrolysis of shrimp myofibrillar protein (SMP) and formation of volatile compounds, the fermented broth of Virgibacillus halodenitrificans was purified and the protease was identified as peptidase S8. The enzyme had optimum activity at pH 7.0-8.
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January 2025
Morphogenesis of Macro Algae, UMR8227, CNRS - Sorbonne University, Station Biologique de Roscoff, Place Georges Teissier, Roscoff, 29680, France.
The initiation of embryogenesis in the kelp Saccharina latissima is accompanied by significant anisotropy in cell shape. Using monoclonal antibodies, we show that this anisotropy coincides with a spatio-temporal pattern of accumulation of alginates in the cell wall of the zygote and embryo. Alginates rich in guluronates as well as sulphated fucans show a homogeneous distribution in the embryo throughout Phase I of embryogenesis, but mannuronate alginates accumulate mainly on the sides of the zygote and embryo, disappearing as the embryo enlarges at the start of Phase II.
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