The actin cytoskeleton drives many essential biological processes, from cell morphogenesis to motility. Assembly of functional actin networks requires control over the speed at which actin filaments grow. How this can be achieved at the high and variable levels of soluble actin subunits found in cells is unclear. Here we reconstitute assembly of mammalian, non-muscle actin filaments from physiological concentrations of profilin-actin. We discover that under these conditions, filament growth is limited by profilin dissociating from the filament end and the speed of elongation becomes insensitive to the concentration of soluble subunits. Profilin release can be directly promoted by formin actin polymerases even at saturating profilin-actin concentrations. We demonstrate that mammalian cells indeed operate at the limit to actin filament growth imposed by profilin and formins. Our results reveal how synergy between profilin and formins generates robust filament growth rates that are resilient to changes in the soluble subunit concentration.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6867828 | PMC |
http://dx.doi.org/10.7554/eLife.50963 | DOI Listing |
World J Oncol
February 2025
Breast Surgery, Department of Surgical Oncology, Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA.
Background: Peritumoral lidocaine infiltration prior to excision is associated with better survival in breast cancer (BC), which led us to hypothesize that innervation to the tumor affects its biology and patient survival. Activity-regulated cytoskeleton-associated protein (ARC) gene expression is known to be regulated by neuronal activity. Therefore, we studied the clinical relevance of ARC gene expression as a surrogate of neuronal activity in BC.
View Article and Find Full Text PDFMRS Bull
November 2024
Bioelectronics & Bioenergy Research Lab, Centre for Functional Ecology-Science for People & the Planet, Associate Laboratory TERRA, Department of Life Sciences, University of Coimbra, Coimbra, Portugal.
Abstract: Filamentous cyanobacteria originate toxic harmful algal blooms (HABs) in aquatic ecosystems, severely impacting freshwater ecosystems and life. Despite being natural bloomers, these microorganisms are challenging to handle , due to the formation of aggregates with entangled filaments. Consequently, their precise growth dynamics, although vital to timely predict HABs, remains inaccessible.
View Article and Find Full Text PDFACS Appl Bio Mater
January 2025
Department of Biomedical Engineering and Chemical Engineering, The University of Texas at San Antonio, San Antonio, Texas 78249, United States.
Developing scaffolds supporting functional cell attachment and tissue growth is critical in basic cell research, tissue engineering, and regenerative medicine approaches. Though poly(ethylene glycol) (PEG) and its derivatives are attractive for hydrogels and scaffold fabrication, they often require bioactive modifications due to their bioinert nature. In this work, biomimetic synthesized conductive polypyrrole-poly(3,4-ethylenedioxythiophene) copolymer doped with poly(styrenesulfonate) (PPy-PEDOT:PSS) was used as a biocompatible coating for poly(ethylene glycol) diacrylate (PEGDA) hydrogel to support neuronal and muscle cells' attachment, activity, and differentiation.
View Article and Find Full Text PDFTrends Cell Biol
January 2025
Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, 44227 Dortmund, Germany. Electronic address:
The dynamic turnover of actin filaments drives the morphogenesis and migration of all eukaryotic cells. This review summarizes recent insights into the molecular mechanisms of actin polymerization and disassembly obtained through high-resolution structures of actin filament assemblies. We first describe how, upon polymerization, actin subunits age within the filament through changes in their associated adenine nucleotide.
View Article and Find Full Text PDFJ Cell Biol
March 2025
Cell Biology, Neurobiology and Biophysics, Department of Biology, Faculty of Science, Utrecht University, Utrecht, The Netherlands.
Centrioles are microtubule-based organelles required for the formation of centrosomes and cilia. Centriolar microtubules, unlike their cytosolic counterparts, are stable and grow very slowly, but the underlying mechanisms are poorly understood. Here, we reconstituted in vitro the interplay between the proteins that cap distal centriole ends and control their elongation: CP110, CEP97, and CPAP/SAS-4.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!