Manipulating the Intracellular Trafficking of Nucleic Acids
Kenneth L. Brigham in Gene Therapy for Diseases of the Lung, 2020
Kinesin and cytoplasmic dynein are the principal ATPase microtubule-based motors involved in organelle transport (65-68). Each type of motor associates with membranous organelles and directs movement along the length of the microtubule. Dynein drives movement toward the minus end of the microtubule, yielding a net inward flow, whereas kinesin drives movement towards the plus end, generating movement toward the cell periphery (69). Dynein is responsible for movement of endosomal and lysosomal vesicles toward the cell nucleus, while kinesin has been implicated in maintaining the extended distribution of the endoplasmic reticulum, the shape of the Golgi complex, the extension of lysosomes, and trafficking of proteins from Golgi to endoplasmic reticulum (70-72).
Physiology of the Nose and Paranasal Sinuses
John C Watkinson, Raymond W Clarke, Louise Jayne Clark, Adam J Donne, R James A England, Hisham M Mehanna, Gerald William McGarry, Sean Carrie in Basic Sciences Endocrine Surgery Rhinology, 2018
The ultrastructure of all cilia remains the same; however, nasal cilia are somewhat short. The surface membrane of a cilium encloses an organized ultrastructure. The nine outer-paired microtubules enclose a single inner pair of microtubules. The outer pairs of microtubules are linked to one another by nexins and to the inner pair of microtubules by central spokes. In addition, outer pairs of microtubules have both outer and inner dynein arms that are made up of an ATPase. There are two layers of nasal mucus film, the lower layer that is more watery and cilia move freely, and the upper viscous layer. Importantly, there are small hooks on the tips of the cilia to facilitate their movements once they enter the viscous layer.
Cells
Frank J. Dye in Human Life Before Birth, 2019
Cells possess a family of molecular motors made of proteins called dynein. The microtubules (made up of tubulin protein) that make up the core (axoneme) of the sperm tail (flagellum) have dynein protein motors associated with them. These dynein molecules are able to breakdown ATP to release energy. This released energy in the sperm flagellum causes microtubules to tend to slide past each other. However, other protein molecules associated with the microtubules prevent the microtubules from sliding and instead cause them to bend. It is the bending of the microtubules of the flagellum that causes the flagellum to “beat” and the sperm to swim.
Genetic aspects of idiopathic asthenozoospermia as a cause of male infertility
Published in Human Fertility, 2020
Zohreh Heidary, Kioomars Saliminejad, Majid Zaki-Dizaji, Hamid Reza Khorram Khorshid
DNAI1 (dynein axonemal intermediate chain 1), DNAH5 (dynein axonemal heavy chain 5) and DNAH11 (dynein axonemal heavy chain 11) genes encode three proteins belonging to the axonemal dynein cluster, particularly expressed in testis and trachea (Zuccarello, Ferlin, Cazzadore, et al., 2008). Dynein is a family of cytoskeletal motor proteins that move along microtubules in cells. There are two kinds of dynein: (i) cytoplasmic and (ii) axonemal. They convert the chemical energy stored in ATP to mechanical work (Roberts, Kon, Knight, Sutoh, & Burgess, 2013). Three missense mutations (R663C in DNAI1, E2666D in DNAH5 and I13040V in DNAH11) have been associated with AZS, with a frequency of 8.0%. These missense mutations cause substitution of amino acids, which are essential for the protein structure. These three proteins in the axonemal dynein cluster permanently attached to the A tubule of each outer microtubule doublet and transiently attached to the B tubule of the adjacent microtubule doublet, to generate a sliding motion (Zuccarello, Ferlin, Cazzadore, et al., 2008).
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.
Intraflagellar transport proteins are involved in thrombocyte filopodia formation and secretion
Published in Platelets, 2018
Uvaraj Radhakrishnan, Abdullah Alsrhani, Hemalatha Sundaramoorthi, Gauri Khandekar, Meghana Kashyap, Jannon L Fuchs, Brian D Perkins, Yoshihiro Omori, Pudur Jagadeeswaran
Intraflagellar transport (IFT) proteins are present mainly in cells that have either a primary cilium or motile cilia. These functionally conserved proteins are critical in the genesis and maintenance of cilia [1–3]. Different, but overlapping sets of IFT proteins compose two IFT complexes: Complex A is mainly for retrograde transport of substances back from the tip of the cilium, and Complex B is for anterograde transport from the base of the cilium to the tip [4,5]. The motor proteins kinesin and dynein move IFT particles with their cargo along microtubules in the anterograde and retrograde direction, respectively. The primary cilium is present in most vertebrate cell types and plays diverse roles in sensory transduction and other types of signaling [6,7]. Defects in IFT proteins can result in short or absent cilia, signaling abnormalities, and associated ciliopathy symptoms in humans and other mammals [8]. In zebrafish, IFT knockdowns and mutations also lead to phenotypic symptoms of defective cilia signaling [9–12].
Related Knowledge Centers
- Cytoskeleton
- Flagellum
- Intracellular Transport
- Kinesin
- Microtubule
- Motor Protein
- Cilium
- Cell
- Adenosine Triphosphate
- Mitosis