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Understanding the Interaction of Nanoparticles at the Cellular Interface
Published in D. Sakthi Kumar, Aswathy Ravindran Girija, Bionanotechnology in Cancer, 2023
The dynamics of the interaction of NPs with cells and their organelle explains the process of how the NPs end-up inside lysosomes and endosomes. These play a significant role in regulating the intracellular transport and degradation of foreign bodies. Utilizing NPs as carriers of biomolecules or drugs has found a new dimension into medical requirements with improved technical expertise. NPs, after endocytosis, are transported into early endosomes where most of the sorting occurs. Parallelly, the transport of some NPs moves to recycle endosomes, where finally they are excreted out from the cells. NPs inside the early endosomes move into the cell interior along the microtubules. The transport of cargos from late endosomes to lysosomes is a unidirectional process where late endosomes fuse with lysosomal bodies [55]. There are approximately 50−1000 lysosomes of sizes ranging from as small as 0.1 µm to as large as 1.5 µm in a cell. The size and number of lysosomes vary widely based on the environmental cue, type of cell, and disease conditions [56]. The primary function of lysosome is to hydrolyze any biomolecule that comes into it, implying the presence of hydrolases inside the lumen of the organelle. Its lumen also contains various enzyme activators, transport proteins (NPC2), and other protective factors with an acidic pH of 4.5−5.0 maintained with the help of vacuolar ATPase [57].
Structural Organization of the Liver
Published in Robert G. Meeks, Steadman D. Harrison, Richard J. Bull, Hepatotoxicology, 2020
As mentioned above, proteins and lipoproteins are transported through the hepatocytes via membrane-bound vesicles and excreted into the blood. Vesicular transport is also involved in the endocytosis, intracellular transport, and exocytosis of a variety of other substances. Certain macromolecules are internalized specifically by receptor-medicated endocytosis, which differs from nonspecific fluid phase pinocytosis in that it involves binding of the ligand to be internalized to a specific receptor on the surface of the cell. Because endocytosis involves the formation of vesicles containing the ligand through pinching off from the plasma membrane, the ligand remains segregated from the cytoplasma by the surrounding vesicular membrane. Therefore, endocytosis differs from carrier-mediated transport systems, by catalizing the movement of small polar molecules and ions directly across the membrane barrier separating two aqueous compartment (Forgac, 1988).
N-Myristoylation as a Novel Molecular Target for the Design of Chemotherapeutic Drugs
Published in Robert I. Glazer, Developments in Cancer Chemotherapy, 2019
Ronald L. Felsted, Colin Goddard, Constance J. Glover
Acylprotein synthesis originates on either free or membrane-bound polyribosomes. Their subsequent biosynthetic pathways include posttranslational acylation, glycosylation, intracellular transport, and/or compartmental sorting. An understanding of these pathways, especially where and how acylation occurs, will be critical if we hope to design therapeutic strategies targeted at protein acylation.
A review on synthetic chalcone derivatives as tubulin polymerisation inhibitors
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2022
Wenjing Liu, Min He, Yongjun Li, Zhiyun Peng, Guangcheng Wang
Tubulin is a globular protein mainly in kinetoplastid protozoa, which consisting of the alpha (α), beta (β), gamma (γ), delta (δ), epsilon (ε), and zeta (ζ) tubulin families1. Meanwhile, α-tubulin and β-tubulin form a heterodimer, which in turn forms long-chain fibres2. Then 13 parallel long-chain fibres are interlinked to form a hollow tube, which is called microtubule1,3. Microtubules are key components of the cytoskeleton and are involved in a variety of cellular functions such as cell signalling, intracellular transport, secretion, formation and maintenance of cell shape, motor regulation, and cell division4,5. The heterodimers are bound to each other by non-covalent bonds, so the heterodimers can be continuously bound and separated. And the two heterodimers at the two ends of the microtubule can be continuously added and released so that the microtubule can be continuously polymerised and discrete, so there is a dynamic balance state in this process6. When the microtubule is in dynamic balance, one end of the microtubule will release a set of heterodimers, and the other end will bind a set of heterodimers, which can not only keep the length of the microtubule constant but also enable the microtubule to move from one side to the other, thus completing the necessary physiological function.
In vitro cytotoxicity, cellular uptake, reactive oxygen species and cell cycle arrest studies of novel ruthenium(II) polypyridyl complexes towards A549 lung cancer cell line
Published in Drug and Chemical Toxicology, 2021
Muhammad Qasim Warraich, Alessandra Ghion, Laura Perdisatt, Luke O’Neill, Alan Casey, Christine O’Connor
The intracellular transport of small molecules is the main demanding feature that is required to exert their potential effects by interacting with the biological entities within the cells, which ultimately decides their future as an application for a therapeutic or diagnostic tool (Gill and Thomas 2012). Confocal laser scanning microscopy (CLSM) was employed to investigate the cellular uptake of the ruthenium complexes (Puckett and Barton 2007, 2009). Spectrophotometric evaluations were also conducted to confirm that the complexes are stable and can emit fluorescence at a certain wavelength (Table 2). The observed λmax values for the excitation and emission frequencies are related to the values obtained in the original studies (O’Neill, Perdisatt and O’Connor 2012, Perdisatt et al., 2018).
Molecular mechanisms governing axonal transport: a C. elegans perspective
Published in Journal of Neurogenetics, 2020
Amruta Vasudevan, Sandhya P. Koushika
Microtubule-dependent motor proteins responsible for most fast axonal transport in neurons largely belong to the Kinesin or Dynein superfamily (Morfini et al., 2012). Kinesins are ATPases that walk towards the plus ends of microtubules in a hand-over-hand motion, with each motor head taking 16 nm steps for every molecule of ATP hydrolysed (Gennerich & Vale, 2009). Cytoplasmic dynein, a member of the AAA family of ATPases, drives transport towards the minus ends of microtubules, using an inch-worm-like movement with occasional hand-over-hand mode of stepping (Bhabha, Johnson, Schroeder, & Vale, 2016; Gennerich & Vale, 2009). Studies on intracellular transport across diverse cell types have revealed common underlying principles governing microtubule-based transport, such as i) cargo-specific mechanisms of motor recruitment and transport, ii) interactions between multiple motors on the cargo surface, and iii) navigation of the cargo-motor complex through obstacles. Several of these principles have been found to apply to axonal transport. Neurons, being polarized cells with distinct axonal and dendritic compartments, additionally exhibit region-specific regulation of cargo transport. These principles are discussed below.