Centrioles are vital cellular structures that form centrosomes and cilia. The formation function of cilia depends on a set centriole's distal appendages. In this study, we use correlative super resolution electron microscopy to precisely determine where appendage proteins localize in relation the centriole microtubules densities. Here characterize novel protein ANKRD26 detail, high resolution, initial steps assembly. We further show appendages undergo dramatic ultra-structural reorganization...

Newly formed centrioles in cycling cells undergo a maturation process that is almost two cell cycles long before they become competent to function as microtubule-organizing centers and basal bodies. As result, each contains three generations of centrioles, only one which able form cilia. It not known how this complex regulated. We show controlled Plk1 activity required for gradual biochemical structural the timely appendage assembly. Inhibition impeded accumulation proteins formation....

The GTP-tubulin cap is widely accepted to protect microtubules against catastrophe. GTP-cap size thought increase with the microtubule growth rate, presumably endowing fast-growing enhanced stability. It unknown what properties permit frequent catastrophe despite fast growth. Here, we investigate growing in presence and absence of polymerase XMAP215. Using EB1 as a marker, find that increases regardless whether acceleration achieved by increasing tubulin concentration or Despite increased...

Dynamic organization of microtubule minus ends is vital for the formation and maintenance acentrosomal arrays. In vitro, both switch between phases assembly disassembly, a behavior called dynamic instability. Although grow slower, their lifetimes are similar to those plus ends. The mechanisms underlying these distinct dynamics remain unknown. Here, we use an in vitro reconstitution approach investigate minus-end dynamics. We find that not defined by mean size protective GTP-tubulin cap....

Microtubules are dynamic cytoskeletal polymers essential for cell division, motility, and intracellular transport. Microtubule dynamics characterized by instability—the ability of individual microtubules to switch between phases growth shrinkage. Dynamic instability can be explained the GTP-cap model, suggesting that a ‘cap’ GTP-tubulin subunits at growing microtubule end has stabilizing effect, protecting against catastrophe—the from Although is thought protect end, whether size affects...

Abstract The outer surface of chorionic villi in the human placenta consists a single multinucleated cell called syncytiotrophoblast (STB). unique cellular ultrastructure STB presents challenges deciphering its gene expression signature at single-cell level, as contains billions nuclei cell. There are many gaps understanding molecular mechanisms and developmental trajectories involved formation differentiation. To identify underlying control STB, we performed comparative nucleus (SN) (SC)...

Almost 40 years since the discovery of microtubule dynamic instability, molecular mechanisms underlying dynamics remain an area intense research interest. The "standard model" implicates a "cap" GTP-bound tubulin dimers at growing end as main determinant stability. Loss GTP-cap leads to "catastrophe," switch-like transition from growth shrinkage. However, recent studies, using biochemical in vitro reconstitution, cryo-EM, and computational modeling approaches, challenge simple model....

The outer surface of chorionic villi in the human placenta consists a single multinucleated cell called syncytiotrophoblast (STB). unique cellular ultrastructure STB presents challenges deciphering its gene expression signature at single-cell level, as contains billions nuclei cell. There are many gaps understanding molecular mechanisms and developmental trajectories involved formation differentiation. To identify underlying control STB, we performed comparative nucleus (SN) (SC) RNA...

The syncytiotrophoblast (STB) is a multinucleated cell layer that forms the outer surface of human chorionic villi. Its unusual structure, with billions nuclei in single cell, makes it difficult to resolve using conventional single-cell methods. To better understand STB differentiation, we performed single-nucleus and RNA sequencing on placental tissue trophoblast organoids (TOs). Single-nucleus RNA-seq was essential for capturing populations, revealing three nuclear subtypes: juvenile...

The syncytiotrophoblast (STB) is a multinucleated cell layer that forms the outer surface of human chorionic villi. Its unusual structure, with billions nuclei in single cell, makes it difficult to resolve using conventional single-cell methods. To better understand STB differentiation, we performed single-nucleus and RNA sequencing on placental tissue trophoblast organoids (TOs). Single-nucleus RNA-seq was essential for capturing populations, revealing three nuclear subtypes: juvenile...

Microtubule network remodeling is essential for fundamental cellular processes including cell division, differentiation, and motility. Microtubules are active biological polymers whose ends stochastically independently switch between phases of growth shrinkage. treadmilling, in which the microtubule plus end grows while minus shrinks, observed cells; however, underlying mechanisms not known. Here, we use a combination computational vitro reconstitution approaches to determine conditions...

A cascade of alternative sigma factors directs developmental gene expression during spore formation by the bacterium Bacillus subtilis. As develops, a tightly regulated switch occurs in which early-acting factor σF is replaced late-acting σG. The encoding σG (sigG) transcribed and itself an autoregulatory loop; yet activity not detected until σF-dependent complete. This separation activities has been suggested to be due at least part poorly understood intercellular checkpoint pathway that...

The outer surface of chorionic villi in the human placenta consists a single multinucleated cell called syncytiotrophoblast (STB). unique cellular ultrastructure STB presents challenges deciphering its gene expression signature at single-cell level, as contains billions nuclei cell. There are many gaps understanding molecular mechanisms and developmental trajectories involved formation differentiation. To identify underlying control STB, we performed comparative nucleus (SN) (SC) RNA...

ABSTRACT The GTP-tubulin cap is widely accepted to protect microtubules against catastrophe. GTP-cap size thought increase with the microtubule growth rate, presumably endowing fast-growing enhanced stability. It unknown what properties permit frequent catastrophe despite fast growth. Here, we investigate grown in vitro presence and absence of polymerase XMAP215. Using EB1 as a marker, find that increases regardless whether acceleration achieved by increasing tubulin concentration or In...