Gene Transfection Efficiency Improvement with Lipid Conjugated Cationic Carbon Dots.

An ideal vehicle with a high transfection efficiency is crucial for gene delivery. In this study, a type of cationic carbon dot (CCD) known as APCDs were first prepared with arginine (Arg) and pentaethylenehexamine (PEHA) as precursors and conjugated with oleic acid (OA) for gene delivery. By tuning the mass ratio of APCDs to OA, APCDs-OA conjugates, namely, APCDs-0.

The IV International Symposium on Fungal Stress and the XIII International Fungal Biology Conference.

For the first time, the International Symposium on Fungal Stress was joined by the XIII International Fungal Biology Conference. The International Symposium on Fungal Stress (ISFUS), always held in Brazil, is now in its fourth edition, as an event of recognized quality in the international community of mycological research. The event held in São José dos Campos, SP, Brazil, in September 2022, featured 33 renowned speakers from 12 countries, including: Austria, Brazil, France, Germany, Ghana, Hungary, México, Pakistan, Spain, Slovenia, USA, and UK.

Cancer cells inhibition by cationic carbon dots targeting the cellular nucleus.

Nucleus targeting is tremendously important in cancer therapy. Cationic carbon dots (CCDs) are potential nanoparticles which might enter cells and penetrate nuclear membranes. Although some CCDs have been investigated in nucleus targeting and applied in nuclear imaging, the CCDs derived from drugs, that are able to target the nucleus, bind with DNA and inhibit the growth of cancer cells have not been reported.

Cdc42 GTPase-activating proteins (GAPs) regulate generational inheritance of cell polarity and cell shape in fission yeast.

The highly conserved small GTPase Cdc42 regulates polarized cell growth and morphogenesis from yeast to humans. We previously reported that Cdc42 activation exhibits oscillatory dynamics at cell tips of cells. Mathematical modeling suggests that this dynamic behavior enables a variety of symmetric and asymmetric Cdc42 activation distributions to coexist in cell populations.

Conserved NDR/LATS kinase controls RAS GTPase activity to regulate cell growth and chronological lifespan.

Adaptation to the nutritional environment is critical for all cells. RAS GTPase is a highly conserved GTP-binding protein with crucial functions for cell growth and differentiation in response to environmental conditions. Here, we describe a novel mechanism connecting RAS GTPase to nutrient availability in fission yeast.

Spatial control of translation repression and polarized growth by conserved NDR kinase Orb6 and RNA-binding protein Sts5.

RNA-binding proteins contribute to the formation of ribonucleoprotein (RNP) granules by phase transition, but regulatory mechanisms are not fully understood. Conserved fission yeast NDR (Nuclear Dbf2-Related) kinase Orb6 governs cell morphogenesis in part by spatially controlling Cdc42 GTPase. Here we describe a novel, independent function for Orb6 kinase in negatively regulating the recruitment of RNA-binding protein Sts5 into RNPs to promote polarized cell growth.

Phosphorylation-dependent inhibition of Cdc42 GEF Gef1 by 14-3-3 protein Rad24 spatially regulates Cdc42 GTPase activity and oscillatory dynamics during cell morphogenesis.

Active Cdc42 GTPase, a key regulator of cell polarity, displays oscillatory dynamics that are anticorrelated at the two cell tips in fission yeast. Anticorrelation suggests competition for active Cdc42 or for its effectors. Here we show how 14-3-3 protein Rad24 associates with Cdc42 guanine exchange factor (GEF) Gef1, limiting Gef1 availability to promote Cdc42 activation.

Role of Cdc42 dynamics in the control of fission yeast cell polarization.

Cell polarization is fundamental to many cellular processes, including cell differentiation, cell motility and cell fate determination. A key regulatory enzyme in the control of cell morphogenesis is the conserved Rho GTPase Cdc42, which breaks symmetry via self-amplifying positive-feedback mechanisms. Additional mechanisms of control, including competition between different sites of polarized cell growth and time-delayed negative feedback, define a cellular-level system that promotes Cdc42 oscillatory dynamics and modulates activated Cdc42 intracellular distribution.

Oscillatory dynamics of Cdc42 GTPase in the control of polarized growth.

Cells promote polarized growth by activation of Rho-family protein Cdc42 at the cell membrane. We combined experiments and modeling to study bipolar growth initiation in fission yeast. Concentrations of a fluorescent marker for active Cdc42, Cdc42 protein, Cdc42-activator Scd1, and scaffold protein Scd2 exhibited anticorrelated fluctuations and oscillations with a 5-minute average period at polarized cell tips.

Microtubule-dependent spatial organization of mitochondria in fission yeast.

The microtubule cytoskeleton has an important role in the control of mitochondrial distribution in higher eukaryotes. In humans, defects in axonal mitochondrial transport are linked to neurodegenerative diseases. This chapter highlights fission yeast Schizosaccharomyces pombe as a powerful genetic model system for the study of microtubule-dependent mitochondrial movement, dynamics and inheritance.

The conserved NDR kinase Orb6 controls polarized cell growth by spatial regulation of the small GTPase Cdc42.

The conserved NDR kinase regulates cell morphogenesis and polarized cell growth in different eukaryotic cells ranging from yeast to neurons. Although studies have unraveled the mechanism of regulation of NDR kinase activity, the mechanism of morphology control by NDR and the effectors that mediate NDR function are unknown. Via a chemical genetic approach, we show that the fission yeast NDR homolog, Orb6 kinase, maintains polarized cell growth at the cell tips by spatially regulating the localization of Cdc42 GTPase, a key morphology regulator.

In vivo labeling and analysis of mitochondrial translation products in budding and in fission yeasts.

Mitochondrial biogenesis requires the contribution of two genomes and of two compartmentalized protein synthesis systems (nuclear and mitochondrial). Mitochondrial protein synthesis is unique on many respects, including the use of a genetic code with deviations from the universal code, the use of a restricted number of transfer RNAs, and because of the large number of nuclear encoded factors involved in assembly of the mitochondrial biosynthetic apparatus. The mitochondrial biosynthetic apparatus is involved in the actual synthesis of a handful of proteins encoded in the mitochondrial DNA.

Bot1p is required for mitochondrial translation, respiratory function, and normal cell morphology in the fission yeast Schizosaccharomyces pombe.

Maintenance of cell morphology is essential for normal cell function. For eukaryotic cells, a growing body of recent evidence highlights a close interdependence between mitochondrial function, the cytoskeleton, and cell cycle control mechanisms; however, the molecular details of this interconnection are still not completely understood. We have identified a novel protein, Bot1p, in the fission yeast Schizosaccharomyces pombe.

Regulation of cell diameter, For3p localization, and cell symmetry by fission yeast Rho-GAP Rga4p.

Control of cellular dimensions and cell symmetry are critical for development and differentiation. Here we provide evidence that the putative Rho-GAP Rga4p of Schizosaccharomyces pombe controls cellular dimensions. rga4 Delta cells are wider in diameter and shorter in length, whereas Rga4p overexpression leads to reduced diameter of the growing cell tip.

Fission yeast MO25 protein is localized at SPB and septum and is essential for cell morphogenesis.

Cell morphogenesis is of fundamental significance in all eukaryotes for development, differentiation, and cell proliferation. In fission yeast, Drosophila Furry-like Mor2 plays an essential role in cell morphogenesis in concert with the NDR/Tricornered kinase Orb6. Mutations of these genes result in the loss of cell polarity.

Regulation of a formin complex by the microtubule plus end protein tea1p.

The plus ends of microtubules have been speculated to regulate the actin cytoskeleton for the proper positioning of sites of cell polarization and cytokinesis. In the fission yeast Schizosaccharomyces pombe, interphase microtubules and the kelch repeat protein tea1p regulate polarized cell growth. Here, we show that tea1p is directly deposited at cell tips by microtubule plus ends.

A novel RING-finger-like protein Ini1 is essential for cell cycle progression in fission yeast.

We have cloned a fission yeast (Schizosaccharomyces pombe) homologue of Ini, a novel RING-finger-like protein recently identified in rat that interacts with the connexin43 (cx43) promoter and might be important for the response of the cx43 gene to estrogen. S. pombe cells deleted for ini1(+) fail to form colonies and arrest with an elongated cell phenotype, indicating a cell cycle block.

The kelch repeat protein, Tea1, is a potential substrate target of the p21-activated kinase, Shk1, in the fission yeast, Schizosaccharomyces pombe.

The p21-activated kinase (PAK) homolog, Shk1, is a critical component of a multifunctional Ras/Cdc42/PAK complex required for viability, polarized growth and cell shape, and sexual differentiation in the fission yeast, Schizosaccharomyces pombe. Substrate targets of the Shk1 kinase have not previously been described. Here we show that the S.

Control of cell polarity in fission yeast by association of Orb6p kinase with the highly conserved protein methyltransferase Skb1p.

In the fission yeast Schizosaccharomyces pombe, proper establishment and maintenance of cell polarity require Orb6p, a highly conserved serine/threonine kinase involved in regulating both cell morphogenesis and cell cycle control. Orb6p localizes to the cell tips during interphase and to the cell septum during mitosis. To investigate the mechanisms involved in Orb6p function, we conducted a two-hybrid screen to identify proteins that interact with Orb6p.

Mob2p interacts with the protein kinase Orb6p to promote coordination of cell polarity with cell cycle progression.

The molecular mechanisms that temporally and spatially coordinate cell morphogenesis with the cell cycle remain poorly understood. Here we describe the characterization of fission yeast Mob2p, a novel protein required for regulating cell polarity and cell cycle control. Deletion of mob2 is lethal and causes cells to become spherical, with depolarized actin and microtubule cytoskeletons.