keyword
MENU ▼
Read by QxMD icon Read
search

Apical polarity

keyword
https://www.readbyqxmd.com/read/28346477/disruption-of-sorcs2-reveals-differences-in-the-regulation-of-stereociliary-bundle-formation-between-hair-cell-types-in-the-inner-ear
#1
Andrew Forge, Ruth R Taylor, Sally J Dawson, Michael Lovett, Daniel J Jagger
Behavioural anomalies suggesting an inner ear disorder were observed in a colony of transgenic mice. Affected animals were profoundly deaf. Severe hair bundle defects were identified in all outer and inner hair cells (OHC, IHC) in the cochlea and in hair cells of vestibular macular organs, but hair cells in cristae were essentially unaffected. Evidence suggested the disorder was likely due to gene disruption by a randomly inserted transgene construct. Whole-genome sequencing identified interruption of the SorCS2 (Sortilin-related VPS-10 domain containing protein) locus...
March 27, 2017: PLoS Genetics
https://www.readbyqxmd.com/read/28346438/basolateral-protrusion-and-apical-contraction-cooperatively-drive-drosophila-germ-band-extension
#2
Zijun Sun, Christopher Amourda, Murat Shagirov, Yusuke Hara, Timothy E Saunders, Yusuke Toyama
Throughout development, tissues undergo complex morphological changes, resulting from cellular mechanics that evolve over time and in three-dimensional space. During Drosophila germ-band extension (GBE), cell intercalation is the key mechanism for tissue extension, and the associated apical junction remodelling is driven by polarized myosin-II-dependent contraction. However, the contribution of the basolateral cellular mechanics to GBE remains poorly understood. Here, we characterize how cells coordinate their shape from the apical to the basal side during rosette formation, a hallmark of cell intercalation...
March 27, 2017: Nature Cell Biology
https://www.readbyqxmd.com/read/28338985/regulatory-mechanisms-and-cellular-functions-of-non-centrosomal-microtubules
#3
Michiru Nishita, Tomoko Satake, Yasuhiro Minami, Atsushi Suzuki
Proper organization of microtubule (MT) arrays is essential for numerous cellular functions, including intracellular transport and cell migration. Although the centrosome generally serves as the primary MT organizing center in proliferating animal cells, MTs are also organized at the Golgi apparatus in a wide range of cell types to regulate Golgi ribbon formation that is required for polarized cell migration. Furthermore, differentiated epithelial cells and neurons possess organized non-centrosomal MTs predominantly at the apical cortical regions and the axonal and dendritic neurites, respectively, to establish and maintain their highly polarized morphology...
March 14, 2017: Journal of Biochemistry
https://www.readbyqxmd.com/read/28331073/stability-and-function-of-a-putative-microtubule-organizing-center-in-the-human-parasite-toxoplasma-gondii
#4
Jacqueline M Leung, Yudou He, Fangliang Zhang, Yu-Chen Hwang, Eiji Nagayasu, Jun Liu, John M Murray, Ke Hu
The organization of the microtubule cytoskeleton is dictated by microtubule nucleators or organizing centers.  Toxoplasma gondii, an important human parasite, has an array of 22 regularly spaced cortical microtubules stemming from a hypothesized organizing center, the apical polar ring. Here, we examine the functions of the apical polar ring by characterizing two of its components, KinesinA and APR1, and discovered that its putative role in templating can be separated from its mechanical stability. Parasites that lack both KinesinA and APR1 (ΔkinesinAΔapr1) are capable of generating 22 cortical microtubules...
March 22, 2017: Molecular Biology of the Cell
https://www.readbyqxmd.com/read/28319357/par3-in-chick-lens-placode-development
#5
Maraysa de Oliveira Melo, Ricardo Moraes Borges, Chao Yun Irene Yan
The lens originates from a simple cuboidal epithelium, which, on its basal side, contacts the optic vesicle, whilst facing the extraembryonic environment on its apical side. As this epithelium changes into the pseudostratified lens placode, its cells elongate and become narrower at their apical ends. This is due to the formation of an apical actin network, whose appearance is restricted to cells of the placodal region, as a result of region-specific signaling mechanisms that remain largely unknown. Here, we investigated the role of the polarity protein PAR3 and the phosphorylation state of its Threonine 833 (T833) aPKC-binding site in the recruitment of aPKC and in the establishment of actin network in the chick lens placode...
March 20, 2017: Genesis: the Journal of Genetics and Development
https://www.readbyqxmd.com/read/28315795/differential-auxin-transport-and-accumulation-in-the-stem-base-lead-to-profuse-adventitious-root-primordia-formation-in-the-aerial-roots-aer-mutant-of-tomato-solanum-lycopersicum-l
#6
F Mignolli, L Mariotti, P Picciarelli, M L Vidoz
The aerial roots (aer) mutant of tomato is characterized by a profuse and precocious formation of adventitious root primordia along the stem. We demonstrated that auxin is involved in the aer phenotype but ruled out higher auxin sensitivity of mutant plants. Interestingly, polar auxin transport was altered in aer, as young seedlings showed a reduced response to an auxin transport inhibitor and higher expression of auxin export carriers SlPIN1 and SlPIN3. An abrupt reduction in transcripts of auxin efflux and influx genes in older aer hypocotyls caused a marked deceleration of auxin transport in more mature tissues...
February 27, 2017: Journal of Plant Physiology
https://www.readbyqxmd.com/read/28298318/a-novel-proteolytic-event-controls-hedgehog-intracellular-sorting-and-distribution-to-receptive-fields
#7
Joseph R Daniele, Tehyen Chu, Sam Kunes
The patterning activity of a morphogen depends on secretion and dispersal mechanisms that shape its distribution to the cells of a receptive field. In the case of the protein Hedgehog (Hh), these mechanisms of secretion and transmission remain unclear. In the developing Drosophila visual system, Hedgehog is partitioned for release at opposite poles of photoreceptor neurons. Release into the retina regulates the progression of eye development; axon transport and release at axon termini trigger the development of postsynaptic neurons in the brain...
March 15, 2017: Biology Open
https://www.readbyqxmd.com/read/28293554/sonic-hedgehog-signaling-in-limb-development
#8
REVIEW
Cheryll Tickle, Matthew Towers
The gene encoding the secreted protein Sonic hedgehog (Shh) is expressed in the polarizing region (or zone of polarizing activity), a small group of mesenchyme cells at the posterior margin of the vertebrate limb bud. Detailed analyses have revealed that Shh has the properties of the long sought after polarizing region morphogen that specifies positional values across the antero-posterior axis (e.g., thumb to little finger axis) of the limb. Shh has also been shown to control the width of the limb bud by stimulating mesenchyme cell proliferation and by regulating the antero-posterior length of the apical ectodermal ridge, the signaling region required for limb bud outgrowth and the laying down of structures along the proximo-distal axis (e...
2017: Frontiers in Cell and Developmental Biology
https://www.readbyqxmd.com/read/28289060/the-crumbs3-polarity-protein
#9
Ben Margolis
The Crumbs proteins are evolutionarily conserved apical transmembrane proteins. Drosophila Crumbs was discovered via its crucial role in epithelial polarity during fly embryogenesis. Crumbs proteins have variable extracellular domains but a highly conserved intracellular domain that can bind FERM and PDZ domain proteins. Mammals have three Crumbs genes and this review focuses on Crumbs3, the major Crumbs isoform expressed in mammalian epithelial cells. Although initial work has highlighted the role of Crumbs3 in polarity, more recent studies have found it has an important role in tissue morphogenesis functioning as a linker between the apical membrane and the actin cytoskeleton...
March 13, 2017: Cold Spring Harbor Perspectives in Biology
https://www.readbyqxmd.com/read/28283405/coordination-of-limb-development-by-crosstalk-among-axial-patterning-pathways
#10
REVIEW
Irene Delgado, Miguel Torres
Vertebrate limb development relies on the activity of signaling centers that promote growth and control patterning along three orthogonal axes of the limb bud. The apical ectodermal ridge, at the distal rim of the limb bud ectoderm, produces WNT and FGF signals, which promote limb bud growth and progressive distalization. The zone of polarizing activity, a discrete postero-distal mesenchymal domain, produces SHH, which stimulates growth and organizes patterning along the antero-posterior axis. The dorsal and ventral ectoderms produce, respectively, WNT7A and BMPs, which induce dorso-ventral limb fates...
March 7, 2017: Developmental Biology
https://www.readbyqxmd.com/read/28275682/celiac-disease-role-of-the-epithelial-barrier
#11
REVIEW
Michael Schumann, Britta Siegmund, Jörg D Schulzke, Michael Fromm
In celiac disease (CD) a T-cell-mediated response to gluten is mounted in genetically predisposed individuals, resulting in a malabsorptive enteropathy histologically highlighted by villous atrophy and crypt hyperplasia. Recent data point to the epithelial layer as an under-rated hot spot in celiac pathophysiology to date. This overview summarizes current functional and genetic evidence on the role of the epithelial barrier in CD, consisting of the cell membranes and the apical junctional complex comprising sealing as well as ion and water channel-forming tight junction proteins and the adherens junction...
March 2017: Cellular and Molecular Gastroenterology and Hepatology
https://www.readbyqxmd.com/read/28270611/coordination-of-auxin-triggered-leaf-initiation-by-tomato-leafless
#12
Yossi Capua, Yuval Eshed
Lateral plant organs, particularly leaves, initiate at the flanks of the shoot apical meristem (SAM) following auxin maxima signals; however, little is known about the underlying mechanisms. Here, we show that tomato leafless (lfs) mutants fail to produce cotyledons and leaves and grow a naked pin while maintaining an active SAM. A similar phenotype was observed among pin-like shoots induced by polar auxin transport inhibitors such as 2,3,5-triiodobenzoic acid (TIBA). Both types of pin-like shoots showed reduced expression of primordia markers as well as abnormal auxin distribution, as evidenced by expression of the auxin reporters pPIN1:PIN1:GFP and DR5:YFP Upon auxin microapplication, both lfs meristems and TIBA-pin apices activated DR5:YFP expression with similar kinetics; however, only lfs plants failed to concurrently initiate leaf primordia...
March 7, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28266911/transcription-factor-emx2-controls-stereociliary-bundle-orientation-of-sensory-hair-cells
#13
Tao Jiang, Katie Kindt, Doris K Wu
The asymmetric location of stereociliary bundle (hair bundle) on apical surface of mechanosensory hair cells (HCs) dictates the direction in which a given HC can respond to cues such as sound, head movements, and water pressure. Notably, vestibular sensory organs of the inner ear, the maculae, exhibit a line of polarity reversal (LPR) across which, hair bundles are polarized in a mirror-image pattern. Similarly, HCs in neuromasts of the zebrafish lateral line system are generated as pairs, and two sibling HCs develop opposite hair bundle orientations...
March 7, 2017: ELife
https://www.readbyqxmd.com/read/28264837/distinct-and-redundant-functions-of-esam-and-ve-cadherin-during-vascular-morphogenesis
#14
Loïc Sauteur, Markus Affolter, Heinz-Georg Belting
The cardiovascular system forms during early embryogenesis and adapts to embryonic growth by sprouting angiogenesis and vascular remodeling. These processes require fine-tuning of cell-cell adhesion to maintain and reestablish endothelial contacts, while allowing cell motility. We have compared the contribution of two endothelial cell specific adhesion proteins - VE-cadherin (VE-cad/Cdh5) and Esama (Endothelial cell-selective adhesion molecule a) - during angiogenic sprouting and blood vessel fusion (anastomosis) in the zebrafish embryo by genetic analyses...
March 6, 2017: Development
https://www.readbyqxmd.com/read/28264821/role-of-polarity-proteins-in-the-generation-and-organization-of-apical-surface-protrusions
#15
Gerard Apodaca
Protruding from the apical surfaces of epithelial cells are specialized structures, including cilia, microplicae, microvilli, and stereocilia. These contribute to epithelial function by cushioning the apical surface, by amplifying its surface area to facilitate nutrient absorption, and by promoting sensory transduction and barrier function. Despite these important roles, and the diseases that result when their formation is perturbed, there remain significant gaps in our understanding of the biogenesis of apical protrusions, or the pathways that promote their organization and orientation once at the apical surface...
March 6, 2017: Cold Spring Harbor Perspectives in Biology
https://www.readbyqxmd.com/read/28264820/microtubule-motors-in-establishment-of-epithelial-cell-polarity
#16
Geri Kreitzer, Monn Monn Myat
Epithelial cells play a key role in insuring physiological homeostasis by acting as a barrier between the outside environment and internal organs. They are also responsible for the vectorial transport of ions and fluid essential to the function of many organs. To accomplish these tasks, epithelial cells must generate an asymmetrically organized plasma membrane comprised of structurally and functionally distinct apical and basolateral membranes. Adherent and occluding junctions, respectively, anchor cells within a layer and prevent lateral diffusion of proteins in the outer leaflet of the plasma membrane and restrict passage of proteins and solutes through intercellular spaces...
March 6, 2017: Cold Spring Harbor Perspectives in Biology
https://www.readbyqxmd.com/read/28264818/trafficking-ion-transporters-to-the-apical-membrane-of-polarized-intestinal-enterocytes
#17
Amy Christine Engevik, James R Goldenring
Epithelial cells lining the gastrointestinal tract require distinct apical and basolateral domains to function properly. Trafficking and insertion of enzymes and transporters into the apical brush border of intestinal epithelial cells is essential for effective digestion and absorption of nutrients. Specific critical ion transporters are delivered to the apical brush border to facilitate fluid and electrolyte uptake. Maintenance of these apical transporters requires both targeted delivery and regulated membrane recycling...
March 6, 2017: Cold Spring Harbor Perspectives in Biology
https://www.readbyqxmd.com/read/28263180/uncoupling-apical-constriction-from-tissue-invagination
#18
SeYeon Chung, Sangjoon Kim, Deborah J Andrew
Apical constriction is a widely utilized cell shape change linked to folding, bending and invagination of polarized epithelia. It remains unclear how apical constriction is regulated spatiotemporally during tissue invagination and how this cellular process contributes to tube formation in different developmental contexts. Using Drosophila salivary gland (SG) invagination as a model, we show that regulation of folded gastrulation expression by the Fork head transcription factor is required for apicomedial accumulation of Rho kinase and non-muscle myosin II, which coordinate apical constriction...
March 6, 2017: ELife
https://www.readbyqxmd.com/read/28258156/maternal-metabolic-stress-may-affect-oviduct-gatekeeper-function
#19
Lies Jordaens, Veerle Van Hoeck, Veronica Maillo, Alfonso Gutierrez-Adan, Waleed Fawzy A Marei, Bruno Vlaeminck, Sofie Thys, Roger G S Sturmey, Peter Bols, Jo Leroy
We hypothesized that elevated non-esterified fatty acids (NEFA) modify in vitro bovine oviduct epithelial cell (BOEC) metabolism and barrier function. Hereto, BOECs were studied in a polarized system with 24h-treatments at day 9: 1) CONTROL (0µM NEFA + 0%EtOH), 2) SOLVENT CONTROL (0µM NEFA + 0.45%EtOH), 3) BASAL NEFA (720µM NEFA + 0.45%EtOH in the basal compartment), 4) APICAL NEFA (720µM NEFA + 0.45%EtOH in the apical compartment). FITC-albumin was used for monolayer permeability assessment, and related to Transepithelial Electric Resistance (TER)...
March 3, 2017: Reproduction: the Official Journal of the Society for the Study of Fertility
https://www.readbyqxmd.com/read/28251411/a-fish-intestinal-epithelial-barrier-model-established-from-the-rainbow-trout-oncorhynchus-mykiss-cell-line-rtgutgc
#20
Matteo Minghetti, Carolin Drieschner, Nadine Bramaz, Hannah Schug, Kristin Schirmer
The intestine of fish is a multifunctional organ: lined by only a single layer of specialized epithelial cells, it has various physiological roles including nutrient absorption and ion regulation. It moreover comprises an important barrier for environmental toxicants, including metals. Thus far, knowledge of the fish intestine is limited largely to in vivo or ex vivo investigations. Recently, however, the first fish intestinal cell line, RTgutGC, was established, originating from a rainbow trout (Oncorhynchus mykiss)...
March 1, 2017: Cell Biology and Toxicology
keyword
keyword
14304
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"