Shigella generates distinct IAM subpopulations during epithelial cell invasion to promote efficient intracellular niche formation
Eur J Cell Biol. 2023 Dec 29;103(1):151381. doi: 10.1016/j.ejcb.2023.151381. Online ahead of print.ABSTRACTThe facultative intracellular pathogen Shigella flexneri invades non-phagocytic epithelial gut cells. Through a syringe-like apparatus called type 3 secretion system, it injects effector proteins into the host cell triggering actin rearrangements leading to its uptake within a tight vacuole, termed the bacterial-containing vacuole (BCV). Simultaneously, Shigella induces the formation of large vesicles around the entry site, which we refer to as infection-associated macropinosomes (IAMs). After entry, Shigella ruptures...
Source: European Journal of Cell Biology - January 6, 2024 Category: Cytology Authors: Lisa Sanchez Arthur Lensen Michael G Connor M élanie Hamon Jost Enninga Camila Valenzuela Source Type: research
Cofilin-mediated actin filament network flexibility facilitates 2D to 3D actomyosin shape change
Eur J Cell Biol. 2023 Dec 26;103(1):151379. doi: 10.1016/j.ejcb.2023.151379. Online ahead of print.ABSTRACTThe organization of actin filaments (F-actin) into crosslinked networks determines the transmission of mechanical stresses within the cytoskeleton and subsequent changes in cell and tissue shape. Principally mediated by proteins such as α-actinin, F-actin crosslinking increases both network connectivity and rigidity, thereby facilitating stress transmission at low crosslinking yet attenuating transmission at high crosslinker concentration. Here, we engineer a two-dimensional model of the actomyosin cytoskeleton, in w...
Source: European Journal of Cell Biology - January 3, 2024 Category: Cytology Authors: Zachary Gao Sun Vikrant Yadav Sorosh Amiri Wenxiang Cao Enrique M De La Cruz Michael Murrell Source Type: research
Target lysis by cholesterol extraction is a rate limiting step in the resolution of phagolysosomes
We report that the degradation of targets such as splenocytes and erythrocytes by phagolysosomes occurs in a stepwise fashion, requiring lysis of their plasmalemmal bilayer as an essential initial step. This is achieved by the direct extraction of cholesterol facilitated by Niemann-Pick protein type C2 (NPC2), which in turn hands off cholesterol to NPC1 for export from the phagolysosome. The removal of cholesterol ulimately destabilizes and permeabilizes the membrane of the phagocytic target, allowing access of hydrolases to its internal compartments. In contrast, we found that saposins, which activate the hydrolysis of sp...
Source: European Journal of Cell Biology - January 3, 2024 Category: Cytology Authors: Dante Barreda Sergio Grinstein Spencer A Freeman Source Type: research
Cofilin-mediated actin filament network flexibility facilitates 2D to 3D actomyosin shape change
Eur J Cell Biol. 2023 Dec 26;103(1):151379. doi: 10.1016/j.ejcb.2023.151379. Online ahead of print.ABSTRACTThe organization of actin filaments (F-actin) into crosslinked networks determines the transmission of mechanical stresses within the cytoskeleton and subsequent changes in cell and tissue shape. Principally mediated by proteins such as α-actinin, F-actin crosslinking increases both network connectivity and rigidity, thereby facilitating stress transmission at low crosslinking yet attenuating transmission at high crosslinker concentration. Here, we engineer a two-dimensional model of the actomyosin cytoskeleton, in w...
Source: European Journal of Cell Biology - January 3, 2024 Category: Cytology Authors: Zachary Gao Sun Vikrant Yadav Sorosh Amiri Wenxiang Cao Enrique M De La Cruz Michael Murrell Source Type: research
Target lysis by cholesterol extraction is a rate limiting step in the resolution of phagolysosomes
We report that the degradation of targets such as splenocytes and erythrocytes by phagolysosomes occurs in a stepwise fashion, requiring lysis of their plasmalemmal bilayer as an essential initial step. This is achieved by the direct extraction of cholesterol facilitated by Niemann-Pick protein type C2 (NPC2), which in turn hands off cholesterol to NPC1 for export from the phagolysosome. The removal of cholesterol ulimately destabilizes and permeabilizes the membrane of the phagocytic target, allowing access of hydrolases to its internal compartments. In contrast, we found that saposins, which activate the hydrolysis of sp...
Source: European Journal of Cell Biology - January 3, 2024 Category: Cytology Authors: Dante Barreda Sergio Grinstein Spencer A Freeman Source Type: research
Cofilin-mediated actin filament network flexibility facilitates 2D to 3D actomyosin shape change
Eur J Cell Biol. 2023 Dec 26;103(1):151379. doi: 10.1016/j.ejcb.2023.151379. Online ahead of print.ABSTRACTThe organization of actin filaments (F-actin) into crosslinked networks determines the transmission of mechanical stresses within the cytoskeleton and subsequent changes in cell and tissue shape. Principally mediated by proteins such as α-actinin, F-actin crosslinking increases both network connectivity and rigidity, thereby facilitating stress transmission at low crosslinking yet attenuating transmission at high crosslinker concentration. Here, we engineer a two-dimensional model of the actomyosin cytoskeleton, in w...
Source: European Journal of Cell Biology - January 3, 2024 Category: Cytology Authors: Zachary Gao Sun Vikrant Yadav Sorosh Amiri Wenxiang Cao Enrique M De La Cruz Michael Murrell Source Type: research
Target lysis by cholesterol extraction is a rate limiting step in the resolution of phagolysosomes
We report that the degradation of targets such as splenocytes and erythrocytes by phagolysosomes occurs in a stepwise fashion, requiring lysis of their plasmalemmal bilayer as an essential initial step. This is achieved by the direct extraction of cholesterol facilitated by Niemann-Pick protein type C2 (NPC2), which in turn hands off cholesterol to NPC1 for export from the phagolysosome. The removal of cholesterol ulimately destabilizes and permeabilizes the membrane of the phagocytic target, allowing access of hydrolases to its internal compartments. In contrast, we found that saposins, which activate the hydrolysis of sp...
Source: European Journal of Cell Biology - January 3, 2024 Category: Cytology Authors: Dante Barreda Sergio Grinstein Spencer A Freeman Source Type: research
Direct observation of cortactin protecting Arp2/3-actin filament branch junctions from GMF-mediated destabilization
Eur J Cell Biol. 2023 Dec 5;103(1):151378. doi: 10.1016/j.ejcb.2023.151378. Online ahead of print.ABSTRACTHow cells tightly control the formation and turnover of branched actin filament arrays to drive cell motility, endocytosis, and other cellular processes is still not well understood. Here, we investigated the mechanistic relationship between two binding partners of the Arp2/3 complex, glia maturation factor (GMF) and cortactin. Individually, GMF and cortactin have opposite effects on the stability of actin filament branches, but it is unknown how they work in concert with each other to govern branch turnover. Using TIR...
Source: European Journal of Cell Biology - December 10, 2023 Category: Cytology Authors: Emma R McGuirk Neha Koundinya Priyashree Nagarajan Shae B Padrick Bruce L Goode Source Type: research
Direct observation of cortactin protecting Arp2/3-actin filament branch junctions from GMF-mediated destabilization
Eur J Cell Biol. 2023 Dec 5;103(1):151378. doi: 10.1016/j.ejcb.2023.151378. Online ahead of print.ABSTRACTHow cells tightly control the formation and turnover of branched actin filament arrays to drive cell motility, endocytosis, and other cellular processes is still not well understood. Here, we investigated the mechanistic relationship between two binding partners of the Arp2/3 complex, glia maturation factor (GMF) and cortactin. Individually, GMF and cortactin have opposite effects on the stability of actin filament branches, but it is unknown how they work in concert with each other to govern branch turnover. Using TIR...
Source: European Journal of Cell Biology - December 10, 2023 Category: Cytology Authors: Emma R McGuirk Neha Koundinya Priyashree Nagarajan Shae B Padrick Bruce L Goode Source Type: research
Direct observation of cortactin protecting Arp2/3-actin filament branch junctions from GMF-mediated destabilization
Eur J Cell Biol. 2023 Dec 5;103(1):151378. doi: 10.1016/j.ejcb.2023.151378. Online ahead of print.ABSTRACTHow cells tightly control the formation and turnover of branched actin filament arrays to drive cell motility, endocytosis, and other cellular processes is still not well understood. Here, we investigated the mechanistic relationship between two binding partners of the Arp2/3 complex, glia maturation factor (GMF) and cortactin. Individually, GMF and cortactin have opposite effects on the stability of actin filament branches, but it is unknown how they work in concert with each other to govern branch turnover. Using TIR...
Source: European Journal of Cell Biology - December 10, 2023 Category: Cytology Authors: Emma R McGuirk Neha Koundinya Priyashree Nagarajan Shae B Padrick Bruce L Goode Source Type: research
Direct observation of cortactin protecting Arp2/3-actin filament branch junctions from GMF-mediated destabilization
Eur J Cell Biol. 2023 Dec 5;103(1):151378. doi: 10.1016/j.ejcb.2023.151378. Online ahead of print.ABSTRACTHow cells tightly control the formation and turnover of branched actin filament arrays to drive cell motility, endocytosis, and other cellular processes is still not well understood. Here, we investigated the mechanistic relationship between two binding partners of the Arp2/3 complex, glia maturation factor (GMF) and cortactin. Individually, GMF and cortactin have opposite effects on the stability of actin filament branches, but it is unknown how they work in concert with each other to govern branch turnover. Using TIR...
Source: European Journal of Cell Biology - December 10, 2023 Category: Cytology Authors: Emma R McGuirk Neha Koundinya Priyashree Nagarajan Shae B Padrick Bruce L Goode Source Type: research
Direct observation of cortactin protecting Arp2/3-actin filament branch junctions from GMF-mediated destabilization
Eur J Cell Biol. 2023 Dec 5;103(1):151378. doi: 10.1016/j.ejcb.2023.151378. Online ahead of print.ABSTRACTHow cells tightly control the formation and turnover of branched actin filament arrays to drive cell motility, endocytosis, and other cellular processes is still not well understood. Here, we investigated the mechanistic relationship between two binding partners of the Arp2/3 complex, glia maturation factor (GMF) and cortactin. Individually, GMF and cortactin have opposite effects on the stability of actin filament branches, but it is unknown how they work in concert with each other to govern branch turnover. Using TIR...
Source: European Journal of Cell Biology - December 10, 2023 Category: Cytology Authors: Emma R McGuirk Neha Koundinya Priyashree Nagarajan Shae B Padrick Bruce L Goode Source Type: research
Direct observation of cortactin protecting Arp2/3-actin filament branch junctions from GMF-mediated destabilization
Eur J Cell Biol. 2023 Dec 5;103(1):151378. doi: 10.1016/j.ejcb.2023.151378. Online ahead of print.ABSTRACTHow cells tightly control the formation and turnover of branched actin filament arrays to drive cell motility, endocytosis, and other cellular processes is still not well understood. Here, we investigated the mechanistic relationship between two binding partners of the Arp2/3 complex, glia maturation factor (GMF) and cortactin. Individually, GMF and cortactin have opposite effects on the stability of actin filament branches, but it is unknown how they work in concert with each other to govern branch turnover. Using TIR...
Source: European Journal of Cell Biology - December 10, 2023 Category: Cytology Authors: Emma R McGuirk Neha Koundinya Priyashree Nagarajan Shae B Padrick Bruce L Goode Source Type: research
Direct observation of cortactin protecting Arp2/3-actin filament branch junctions from GMF-mediated destabilization
Eur J Cell Biol. 2023 Dec 5;103(1):151378. doi: 10.1016/j.ejcb.2023.151378. Online ahead of print.ABSTRACTHow cells tightly control the formation and turnover of branched actin filament arrays to drive cell motility, endocytosis, and other cellular processes is still not well understood. Here, we investigated the mechanistic relationship between two binding partners of the Arp2/3 complex, glia maturation factor (GMF) and cortactin. Individually, GMF and cortactin have opposite effects on the stability of actin filament branches, but it is unknown how they work in concert with each other to govern branch turnover. Using TIR...
Source: European Journal of Cell Biology - December 10, 2023 Category: Cytology Authors: Emma R McGuirk Neha Koundinya Priyashree Nagarajan Shae B Padrick Bruce L Goode Source Type: research
Direct observation of cortactin protecting Arp2/3-actin filament branch junctions from GMF-mediated destabilization
Eur J Cell Biol. 2023 Dec 5;103(1):151378. doi: 10.1016/j.ejcb.2023.151378. Online ahead of print.ABSTRACTHow cells tightly control the formation and turnover of branched actin filament arrays to drive cell motility, endocytosis, and other cellular processes is still not well understood. Here, we investigated the mechanistic relationship between two binding partners of the Arp2/3 complex, glia maturation factor (GMF) and cortactin. Individually, GMF and cortactin have opposite effects on the stability of actin filament branches, but it is unknown how they work in concert with each other to govern branch turnover. Using TIR...
Source: European Journal of Cell Biology - December 10, 2023 Category: Cytology Authors: Emma R McGuirk Neha Koundinya Priyashree Nagarajan Shae B Padrick Bruce L Goode Source Type: research
