scholarly journals Tubulin glycylation controls primary cilia length

2017 ◽  
Vol 216 (9) ◽  
pp. 2701-2713 ◽  
Author(s):  
Sudarshan Gadadhar ◽  
Hala Dadi ◽  
Satish Bodakuntla ◽  
Anne Schnitzler ◽  
Ivan Bièche ◽  
...  
Keyword(s):  
Posttranslational Modifications ◽  
Primary Cilia ◽  
Cultured Cells ◽  
Dependent Manner ◽  
Specific Antibodies ◽  
Essential Components ◽  
Human Disorders ◽  
Motile Cilia ◽  
Cilia And Flagella

As essential components of the eukaryotic cytoskeleton, microtubules fulfill a variety of functions that can be temporally and spatially controlled by tubulin posttranslational modifications. Tubulin glycylation has so far been mostly found on motile cilia and flagella, where it is involved in the stabilization of the axoneme. In contrast, barely anything is known about the role of glycylation in primary cilia because of limitations in detecting this modification in these organelles. We thus developed novel glycylation-specific antibodies with which we detected glycylation in many primary cilia. Glycylation accumulates in primary cilia in a length-dependent manner, and depletion or overexpression of glycylating enzymes modulates the length of primary cilia in cultured cells. This strongly suggests that glycylation is essential for the homeostasis of primary cilia, which has important implications for human disorders related to primary cilia dysfunctions, such as ciliopathies and certain types of cancer.

scholarly journals ATAD5 promotes replication restart by regulating RAD51 and PCNA in response to replication stress

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Su Hyung Park ◽  
Nalae Kang ◽  
Eunho Song ◽  
Minwoo Wie ◽  
Eun A. Lee ◽  
...  
Keyword(s):  
Single Molecule ◽  
Protein Interactions ◽  
Cultured Cells ◽  
Replication Stress ◽  
Dependent Manner ◽  
Dna Breaks ◽  
Single Molecule Fret ◽  
Hydroxyurea Treatment ◽  
Fork Regression

AbstractMaintaining stability of replication forks is important for genomic integrity. However, it is not clear how replisome proteins contribute to fork stability under replication stress. Here, we report that ATAD5, a PCNA unloader, plays multiple functions at stalled forks including promoting its restart. ATAD5 depletion increases genomic instability upon hydroxyurea treatment in cultured cells and mice. ATAD5 recruits RAD51 to stalled forks in an ATR kinase-dependent manner by hydroxyurea-enhanced protein-protein interactions and timely removes PCNA from stalled forks for RAD51 recruitment. Consistent with the role of RAD51 in fork regression, ATAD5 depletion inhibits slowdown of fork progression and native 5-bromo-2ʹ-deoxyuridine signal induced by hydroxyurea. Single-molecule FRET showed that PCNA itself acts as a mechanical barrier to fork regression. Consequently, DNA breaks required for fork restart are reduced by ATAD5 depletion. Collectively, our results suggest an important role of ATAD5 in maintaining genome integrity during replication stress.

scholarly journals The role of the dynein light intermediate chain in retrograde IFT and flagellar function in Chlamydomonas

2016 ◽  
Vol 27 (15) ◽  
pp. 2404-2422 ◽  
Author(s):  
Jaimee Reck ◽  
Alexandria M. Schauer ◽  
Kristyn VanderWaal Mills ◽  
Raqual Bower ◽  
Douglas Tritschler ◽  
...  
Keyword(s):  
Intraflagellar Transport ◽  
Small Subset ◽  
Dependent Manner ◽  
Microtubule Motor ◽  
Flagellar Assembly ◽  
Cilia And Flagella ◽  
The Stability ◽  
Mutant Phenotypes ◽  
Intermediate Chain

The assembly of cilia and flagella depends on the activity of two microtubule motor complexes, kinesin-2 and dynein-2/1b, but the specific functions of the different subunits are poorly defined. Here we analyze Chlamydomonas strains expressing different amounts of the dynein 1b light intermediate chain (D1bLIC). Disruption of D1bLIC alters the stability of the dynein 1b complex and reduces both the frequency and velocity of retrograde intraflagellar transport (IFT), but it does not eliminate retrograde IFT. Flagellar assembly, motility, gliding, and mating are altered in a dose-dependent manner. iTRAQ-based proteomics identifies a small subset of proteins that are significantly reduced or elevated in d1blic flagella. Transformation with D1bLIC-GFP rescues the mutant phenotypes, and D1bLIC-GFP assembles into the dynein 1b complex at wild-type levels. D1bLIC-GFP is transported with anterograde IFT particles to the flagellar tip, dissociates into smaller particles, and begins processive retrograde IFT in <2 s. These studies demonstrate the role of D1bLIC in facilitating the recycling of IFT subunits and other proteins, identify new components potentially involved in the regulation of IFT, flagellar assembly, and flagellar signaling, and provide insight into the role of D1bLIC and retrograde IFT in other organisms.

Role of connexins in microvascular dysfunction during inflammation

2011 ◽  
Vol 89 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Karel Tyml
Keyword(s):  
Cultured Cells ◽  
Electrical Coupling ◽  
Microvascular Dysfunction ◽  
Microvascular Endothelial Cells ◽  
Dependent Manner ◽  
Cell Monolayers ◽  
Confluent Cell ◽  
Diameter Change

In arterioles, a locally initiated diameter change can propagate rapidly along the vessel length (arteriolar conducted response), thus contributing to arteriolar hemodynamic resistance. The response is underpinned by electrical coupling along the arteriolar endothelial layer. Connexins (Cx; constituents of gap junctions) are required for this coupling. This review addresses the effect of acute systemic inflammation (sepsis) on arteriolar conduction and interendothelial electrical coupling. Lipopolysaccharide (LPS; an initiating factor in sepsis) and polymicrobial sepsis (24 h model) attenuate conducted vasoconstriction in mice. In cultured microvascular endothelial cells harvested from rat and mouse skeletal muscle, LPS reduces both conducted hyperpolarization–depolarization along capillary-like structures and electrical coupling along confluent cell monolayers. LPS also tyrosine-phosphorylates Cx43 and serine-dephosphorylates Cx40. Since LPS-reduced coupling is Cx40- but not Cx43-dependent, only Cx40 dephosphorylation may be consequential. Nitric oxide (NO) overproduction is critical in advanced sepsis, since the removal of this overproduction prevents the attenuated conduction. Consistently, (i) exogenous NO in cultured cells reduces coupling in a Cx37-dependent manner, and (ii) the septic microvasculature in vivo shows no Cx40 phenotype. A complex role emerges for endothelial connexins in sepsis. Initially, LPS may reduce interendothelial coupling and arteriolar conduction by targeting Cx40, whereas NO overproduction in advanced sepsis reduces coupling and conduction by targeting Cx37 instead.

scholarly journals Signaling the differences between cilia

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Polina Lishko ◽  
Yuriy Kirichok
Keyword(s):  
Ion Channels ◽  
Calcium Ion ◽  
Primary Cilia ◽  
Calcium Ion Channels ◽  
Motile Cilia ◽  
Cilia And Flagella

Calcium ion channels that determine many of the properties of cilia are different in motile cilia as compared to primary cilia and flagella.

scholarly journals Intraflagellar transport-A deficiency attenuates ADPKD in a renal tubular- and maturation-dependent manner

2020 ◽  
Author(s):  
Wei Wang ◽  
Luciane M. Silva ◽  
Henry H. Wang ◽  
Matthew A. Kavanaugh ◽  
Tana S. Pottorf ◽  
...  
Keyword(s):  
Mouse Models ◽  
Primary Cilia ◽  
Protein Complexes ◽  
Collecting Duct ◽  
Intraflagellar Transport ◽  
Renal Tubules ◽  
Dependent Manner ◽  
Cortical Collecting Duct ◽  
Knock Out

AbstractPrimary cilia are sensory organelles that are built and maintained by intraflagellar transport (IFT) multi-protein complexes. Deletion of certain ciliary genes in Autosomal Dominant Polycystic Kidney Disease (ADPKD) mouse models markedly attenuates PKD severity, indicating that a component of cilia dysfunction may have potential therapeutic value. To broaden the role of ciliary dysfunction, here we investigate the role of global deletion of Ift-A gene, Thm1, in juvenile and adult ADPKD mouse models. In cyst-lining cells of both juvenile and adult ADPKD models, cortical collecting duct cilia lengths and cytoplasmic and nuclear levels of the nutrient sensor, O-linked β-Nacetylglucosamine (O-GlcNAc) were increased. Relative to juvenile Pkd2 conditional knock-out mice, deletion of Thm1 together with Pkd2 both increased and reduced cystogenesis in a tubule-specific manner without altering kidney function, inflammation, cilia lengths, and ERK, STAT3 and OGlcNAc signaling. In contrast, Thm1 deletion in adult ADPKD mouse models markedly attenuated almost all features of PKD, including renal cystogenesis, inflammation, cilia lengths, and ERK, STAT3 and O-GlcNAc signaling. These data suggest that differential factors in the microenvironments between renal tubules and between developing and mature kidneys influence cilia and ADPKD pathobiology. Further, since O-GlcNAcylation directly regulates ciliary homeostasis and the balance between glycolysis and oxidative phosphorylation, we propose that increased O-GlcNAcylation may promote certain key ADPKD pathological processes.

scholarly journals Pericentrin forms a complex with intraflagellar transport proteins and polycystin-2 and is required for primary cilia assembly

2004 ◽  
Vol 166 (5) ◽  
pp. 637-643 ◽  
Author(s):  
Agata Jurczyk ◽  
Adam Gromley ◽  
Sambra Redick ◽  
Jovenal San Agustin ◽  
George Witman ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Rna Interference ◽  
Primary Cilia ◽  
Intraflagellar Transport ◽  
Transport Proteins ◽  
Immunogold Electron Microscopy ◽  
Basal Bodies ◽  
Motile Cilia ◽  
Cilia And Flagella ◽  
Centrosome Protein

Primary cilia are nonmotile microtubule structures that assemble from basal bodies by a process called intraflagellar transport (IFT) and are associated with several human diseases. Here, we show that the centrosome protein pericentrin (Pcnt) colocalizes with IFT proteins to the base of primary and motile cilia. Immunogold electron microscopy demonstrates that Pcnt is on or near basal bodies at the base of cilia. Pcnt depletion by RNA interference disrupts basal body localization of IFT proteins and the cation channel polycystin-2 (PC2), and inhibits primary cilia assembly in human epithelial cells. Conversely, silencing of IFT20 mislocalizes Pcnt from basal bodies and inhibits primary cilia assembly. Pcnt is found in spermatocyte IFT fractions, and IFT proteins are found in isolated centrosome fractions. Pcnt antibodies coimmunoprecipitate IFT proteins and PC2 from several cell lines and tissues. We conclude that Pcnt, IFTs, and PC2 form a complex in vertebrate cells that is required for assembly of primary cilia and possibly motile cilia and flagella.

scholarly journals CFAP54 is required for proper ciliary motility and assembly of the central pair apparatus in mice

2015 ◽  
Vol 26 (18) ◽  
pp. 3140-3149 ◽  
Author(s):  
Casey W. McKenzie ◽  
Branch Craige ◽  
Tiffany V. Kroeger ◽  
Rozzy Finn ◽  
Todd A. Wyatt ◽  
...  
Keyword(s):  
Structural Defect ◽  
Beat Frequency ◽  
Critical Role ◽  
Ciliary Beat Frequency ◽  
Dependent Manner ◽  
Flagellar Motility ◽  
Calcium Dependent ◽  
Assembly Mechanism ◽  
Motile Cilia ◽  
Cilia And Flagella

Motile cilia and flagella play critical roles in fluid clearance and cell motility, and dysfunction commonly results in the pediatric syndrome primary ciliary dyskinesia (PCD). CFAP221, also known as PCDP1, is required for ciliary and flagellar function in mice and Chlamydomonas reinhardtii, where it localizes to the C1d projection of the central microtubule apparatus and functions in a complex that regulates flagellar motility in a calcium-dependent manner. We demonstrate that the genes encoding the mouse homologues of the other C. reinhardtii C1d complex members are primarily expressed in motile ciliated tissues, suggesting a conserved function in mammalian motile cilia. The requirement for one of these C1d complex members, CFAP54, was identified in a mouse line with a gene-trapped allele. Homozygous mice have PCD characterized by hydrocephalus, male infertility, and mucus accumulation. The infertility results from defects in spermatogenesis. Motile cilia have a structural defect in the C1d projection, indicating that the C1d assembly mechanism requires CFAP54. This structural defect results in decreased ciliary beat frequency and perturbed cilia-driven flow. This study identifies a critical role for CFAP54 in proper assembly and function of mammalian cilia and flagella and establishes the gene-trapped allele as a new model of PCD.

scholarly journals Scoring a backstage pass: Mechanisms of ciliogenesis and ciliary access

2012 ◽  
Vol 197 (6) ◽  
pp. 697-709 ◽  
Author(s):  
Francesc R. Garcia-Gonzalo ◽  
Jeremy F. Reiter
Keyword(s):  
Cell Surface ◽  
Primary Cilia ◽  
Basal Bodies ◽  
Protein Traffic ◽  
Ciliary Function ◽  
Kidney Cysts ◽  
Motile Cilia ◽  
Cilia And Flagella ◽  
Inborn Defects

Cilia are conserved, microtubule-based cell surface projections that emanate from basal bodies, membrane-docked centrioles. The beating of motile cilia and flagella enables cells to swim and epithelia to displace fluids. In contrast, most primary cilia do not beat but instead detect environmental or intercellular stimuli. Inborn defects in both kinds of cilia cause human ciliopathies, diseases with diverse manifestations such as heterotaxia and kidney cysts. These diseases are caused by defects in ciliogenesis or ciliary function. The signaling functions of cilia require regulation of ciliary composition, which depends on the control of protein traffic into and out of cilia.

scholarly journals Immunological role of primary cilia of dendritic cells in human skin disease

2020 ◽  
Author(s):  
Manami Toriyama ◽  
Defri Rizaldy ◽  
Motoki Nakamura ◽  
Fumitaka Fujita ◽  
Fumihiro Okada ◽  
...  
Keyword(s):  
Dendritic Cells ◽  
Primary Cilia ◽  
Potential Role ◽  
Skin Barrier ◽  
Dependent Manner ◽  
Gm Csf ◽  
Human Immune ◽  
Human Dendritic Cells ◽  
Dc Maturation

AbstractPrimary cilia are a unique organelle, known to provide a signaling hub for variety of cell activities. Their potential role(s) in human immune homeostasis and diseases, however, have yet to be explored. Here, we show that human dendritic cells (DCs) express primary cilia-like structure. The primary cilia growth during DC proliferation by GM-CSF was shut off by DC maturation agents, suggesting the role of primary cilia to transduce proliferation signaling. PDGFRα pathway, one of proliferation signal in primary cilia, promoted DC proliferation in a dependent manner of intra-flagellar transport system. In epidermis with atopic dermatitis patients, aberrant ciliated langerhans cells and keratinocytes with showing immature state were observed that may play a potential role in inflammation and skin barrier disorder.

scholarly journals Protegrin-1 Regulates Porcine Granulosa Cell Proliferation via the EGFR-ERK1/2/p38 Signaling Pathway in vitro

2021 ◽  
Vol 12 ◽  
Author(s):  
Bo Pan ◽  
Canying Liu ◽  
Xiaoshu Zhan ◽  
Julang Li
Keyword(s):  
Cell Proliferation ◽  
Antimicrobial Peptides ◽  
Granulosa Cell ◽  
Kinase Inhibitor ◽  
Mapk Pathway ◽  
Cyclin B1 ◽  
Luciferase Reporter ◽  
Dependent Manner ◽  
Essential Components

Antimicrobial peptides (AMPs) are traditionally known to be essential components in host defense via their broad activities against bacteria, fungi, viruses, and protozoa. Their immunomodulatory properties have also recently received considerable attention in mammalian somatic tissues of various species. However, little is known regarding the role of AMPs in the development and maturation of ovarian follicles. Protegrin-1 (PG-1) is an antimicrobial peptide which is known to have potent antimicrobial activity against both gram positive and negative bacteria. Here we report that the PG-1 is present in the porcine ovarian follicular fluid. Treatment of granulosa cell with PG-1 enhanced granulosa cell proliferation in a dose-dependent manner. This is accompanied by increased expression of cell-cycle progression-related genes such as cyclin D1(CCND1), cyclin D2 (CCND2), and cyclin B1(CCNB1). Additionally, Western blot analysis showed that PG-1 increased phosphorylated epidermal growth factor receptor (EGFR), and the phosphorylated-/total extracellular signal-regulated kinase (ERK)1/2 ratio. Pretreatment with either U0126, a specific ERK1/2 phosphorylation inhibitor, or EGFR kinase inhibitor, AG1478, blocked the PG-1 induced proliferation. Moreover, luciferase reporter assay revealed that ETS domain-containing protein-1 (Elk1) C/EBP homologous protein (CHOP), and the transcription activators downstream of the MAPK pathway, were activated by PG-1. These data collectively suggest that PG-1 may regulate pig granulosa cell proliferation via EGFR-MAPK pathway., Hence, our finding offers insights into the role of antimicrobial peptides on follicular development regulation.

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