AI Article Synopsis
- Endocytic vesicle formation involves a process where the plasma membrane invaginates, forms a bud, and undergoes fission, creating a connection called the fission pore.
- Non-muscle myosin II (NM-2) plays a critical role in this fission process, as its inhibition with blebbistatin significantly prolongs the fission pore's duration and prevents vesicle closure during large endocytic events.
- The study indicates that the ATPase activity of NM-2 is essential for effective membrane scission, particularly during compound endocytosis, as its absence hampers the completion of vesicle formation.
Article Abstract
An endocytic vesicle is formed from a flat plasma membrane patch by a sequential process of invagination, bud formation and fission. The scission step requires the formation of a tubular membrane neck (the fission pore) that connects the endocytic vesicle with the plasma membrane. Progress in vesicle fission can be measured by the formation and closure of the fission pore. Live-cell imaging and sensitive biophysical measurements have provided various glimpses into the structure and behaviour of the fission pore. In the present study, the role of non-muscle myosin II (NM-2) in vesicle fission was tested by analyzing the kinetics of the fission pore with perforated-patch clamp capacitance measurements to detect single vesicle endocytosis with millisecond time resolution in peritoneal mast cells. Blebbistatin, a specific inhibitor of NM-2, dramatically increased the duration of the fission pore and also prevented closure during large endocytic events. Using the fluorescent markers FM1-43 and pHrodo Green dextran, we found that NM-2 inhibition greatly arrested vesicle fission in a late phase of the scission event when the pore reached a final diameter of ∼ 5 nm. Our results indicate that loss of the ATPase activity of myosin II drastically reduces the efficiency of membrane scission by making vesicle closure incomplete and suggest that NM-2 might be especially relevant in vesicle fission during compound endocytosis.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4069105 | PMC |
| http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0100757 | PLOS |
Publication Analysis
Top Keywords
Similar Publications
Microautophagy in cereal grains: protein storage or degradation?
Trends Plant Sci
January 2025
University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria; University of Applied Sciences Dresden, Pillnitzer Platz 2, 01326 Dresden, Germany. Electronic address:
Recent research indicates an involvement of microautophagy in the uptake of seed storage proteins (SSPs) into the plant-specific protein storage vacuole (PSV), particularly in cereal grains. However, because microautophagy plays a vital role in cellular homeostasis by degrading and recycling cellular components, we question whether it is a suitable term for a process involved in long-term storage. Additionally, because fission-type microautophagy shares mechanistic similarities with the intraluminal vesicle (ILV) formation of multivesicular bodies (MVBs), we draw parallels between microautophagy and membrane remodeling facilitated by the endosomal sorting complex required for transport (ESCRT).
View Article and Find Full Text PDFIn Vitro Formation of Actin Ring in the Fission Yeast Cell Extracts.
Cytoskeleton (Hoboken)
January 2025
Department of Life Science, Faculty of Science, Gakushuin University, Mejiro, Tokyo, Japan.
Cytokinesis in animal and fungal cells requires the contraction of actomyosin-based contractile rings formed in the division cortex of the cell during late mitosis. However, the detailed mechanism remains incompletely understood. Here, we aim to develop a novel cell-free system by encapsulating cell extracts obtained from fission yeast cells within lipid vesicles, which subsequently leads to the formation of a contractile ring-like structure inside the vesicles.
View Article and Find Full Text PDFApolipoprotein-L Functions in Membrane Remodeling.
Cells
December 2024
Laboratory of Molecular Parasitology, Institut de Biologie et de Médecine Moléculaires (IBMM), Université Libre de Bruxelles, 6041 Gosselies, Belgium.
The mammalian Apolipoprotein-L families (APOLs) contain several isoforms of membrane-interacting proteins, some of which are involved in the control of membrane dynamics (traffic, fission and fusion). Specifically, human APOL1 and APOL3 appear to control membrane remodeling linked to pathogen infection. Through its association with Non-Muscular Myosin-2A (NM2A), APOL1 controls Golgi-derived trafficking of vesicles carrying the lipid scramblase Autophagy-9A (ATG9A).
View Article and Find Full Text PDFCopper doped bioactive glass promotes matrix vesicles-mediated biomineralization via osteoblast mitophagy and mitochondrial dynamics during bone regeneration.
Bioact Mater
April 2025
Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, 210029, Nanjing, China.
Article Synopsis
- Bone defect repair is a significant challenge in orthopedics, with copper being essential for bone regeneration, but its exact role and mechanisms in this process require further investigation.
- The study introduces copper-doped mesoporous bioactive glass nanoparticles (Cu-MBGNs), emphasizing their ability to enhance osteoblast mitophagy and mitochondrial dynamics, leading to improved calcium phosphate release and biomineralization for faster bone healing.
- By using conditional knockout mice, researchers confirmed that Cu-MBGNs promote bone formation through the autophagy pathway, strengthen mitophagy, and enhance mitochondrial function, pointing to their potential in developing advanced bioactive materials for orthopedic treatments.
The Asgard archaeal ESCRT-III system forms helical filaments and remodels eukaryotic-like membranes.
EMBO J
January 2025
Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, 84105, Israel.
The ESCRT machinery mediates membrane remodeling in numerous processes in cells including cell division and nuclear membrane reformation. The identification of ESCRT homologs in Asgard archaea, currently considered the closest prokaryotic relative of eukaryotes, implies a role for ESCRTs in the membrane remodeling processes that occurred during eukaryogenesis. Yet, the function of these distant ESCRT homologs is mostly unresolved.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!