Molecular Biology of the Cell, Ahead of Print ..read more

Molecular Biology of the Cell, Ahead of Print. Solo, a RhoGEF, is involved in mechanical stress response; however, its molecular mechanism remains unclear. We revealed that Solo directly regulates the localization and activity of PDZ-RhoGEF, both RhoA-targeting GEFs, to regulate actin cytoskeletal remodeling. This signaling cascade is required to activate the cellular response to substrate stiffness. These findings can potentially lead to the discovery of novel molecular mechanisms that regulate the mechanical stress responses of cells via Solo ..read more

Molecular Biology of the Cell, Ahead of Print. It has not been possible to globally inhibit microtubule polymerization into dendritic spines without affecting microtubule dynamics throughout the entire neuron as well as any neighboring cells Transfection with the LifeAct-MTED construct inhibits microtubule polymerization into dendritic spines in a spatially and temporally specific manor, without affecting native microtubule dynamics throughout the dendritic shaft The LifeAct-MTED construct with allow for elucidation of the function of microtubule entry into dendritic spines as well as other ac ..read more

Molecular Biology of the Cell, Ahead of Print. Stathmins are conserved across most animals and implicated in disease biology, but their evolutionary origin and cellular functions are unclear, especially in the case of STMND1, which has not been the subject of any cellular analysis. Our phylogenetic analysis argues that STMND1 is the human representative of the most ancient clade. STMND1 is primarily expressed in mutlicilliated epithelial cells, where it localizes to cilia and regulates the length of primary cilia. Our results indicate that tubulin binding negatively regulates the nuclear trans ..read more

Molecular Biology of the Cell, Ahead of Print. The assembly of BAR domain-containing endosomal coats such as retromer involves BAR-BAR pairing, though recent work suggests that additional structural features contribute to subunit selection We identified features in the unstructured N-termini of two paralogous yeast SNX-BARs, Vps5 and Vin1, that mediate the specific formation of the related retromer and VINE complexes Our findings highlight how disordered regions in SNX-BARs help determine the composition of sorting complexes, thereby clarifying mechanisms of modular membrane coat assembly ..read more

Molecular Biology of the Cell, Ahead of Print ..read more

Molecular Biology of the Cell, Ahead of Print. A variety of microfluidic device designs are widely used to study the behaviors of single bacterial cells between growth conditions, but a quantitative comparison of growth between different devices remained absent. The authors developed a protocol to obtain side-by-side experiments using two different microfluidic approaches, finding that growth rates and interdivision times differ but are precisely compensated by the division ratio distribution. Identical emergent simplicities govern stochastic intergenerational homeostasis of cell sizes across ..read more

Molecular Biology of the Cell, Ahead of Print. Based on their elegant experiments, Patterson et al. (eLife, 2021) concluded that the G2/M transition in fission yeast is controlled by a bistable switch, but we question that conclusion. Using detailed stochastic simulations, we show that the coexisting low and high Cdk1 activity states observed by Patterson et al. can be reproduced by either an irreversible/bistable or a reversible/ultrasensitive switch, and our analysis shows why the experiments of Patterson et al. are inconclusive. We suggest a decisive experiment to distinguish unequivocally ..read more

Molecular Biology of the Cell, Ahead of Print. We focus on patterns of a specific bacterial symbiont's peptidoglycan (PG)-synthesis activity, a critical process supporting bacterial growth and survival from the perspectives of both developmental time (i.e., over different stages of tissue colonization) and spatial locations (i.e., between different tissue-colonization sites). The discovery that PG-synthesis activity varies across different stages and locations during a beneficial infection provides insights into how both mutualistic and pathogenic bacteria must adapt to, and survive long-term ..read more

Molecular Biology of the Cell, Ahead of Print. The tissue-specific functions of mammalian actin nucleation factors are not well understood. Mice lacking the actin nucleation factor WHAMM show signs of a kidney disease resembling Fanconi Syndrome. Kidneys from WHAMM-deficient male mice display abnormalities in structure and reabsorption function. Cultured proximal tubule cells exhibit defects in autophagosome closure and autophagic cargo sequestration. WHAMM and the Arp2/3 complex are important for nutrient reabsorption in the kidney and autophagosome remodeling in proximal tubule cells ..read more