scholarly journals A prefoldin-associated WD-repeat protein (WDR92) is required for the correct architectural assembly of motile cilia

2016 ◽  
Vol 27 (8) ◽  
pp. 1204-1209 ◽  
Author(s):  
Ramila S. Patel-King ◽  
Stephen M. King
Keyword(s):  
Beat Frequency ◽  
Repeat Protein ◽  
Hydrodynamic Coupling ◽  
Transmission Electron ◽  
Motile Cilia ◽  
Wd Repeat ◽  
Phylogenetic Signature ◽  
Incomplete Closure ◽  
Peristaltic Contractions ◽  
Pcr Conditions

WDR92 is a highly conserved WD-repeat protein that has been proposed to be involved in apoptosis and also to be part of a prefoldin-like cochaperone complex. We found that WDR92 has a phylogenetic signature that is generally compatible with it playing a role in the assembly or function of specifically motile cilia. To test this hypothesis, we performed an RNAi-based knockdown of WDR92 gene expression in the planarian Schmidtea mediterranea and were able to achieve a robust reduction in mRNA expression to levels undetectable under our standard RT-PCR conditions. We found that this treatment resulted in a dramatic reduction in the rate of organismal movement that was caused by a switch in the mode of locomotion from smooth, cilia-driven gliding to muscle-based, peristaltic contractions. Although the knockdown animals still assembled cilia of normal length and in similar numbers to controls, these structures had reduced beat frequency and did not maintain hydrodynamic coupling. By transmission electron microscopy we observed that many cilia had pleiomorphic defects in their architecture, including partial loss of dynein arms, incomplete closure of the B-tubule, and occlusion or replacement of the central pair complex by accumulated electron-dense material. These observations suggest that WDR92 is part of a previously unrecognized cytoplasmic chaperone system that is specifically required to fold key components necessary to build motile ciliary axonemes.

scholarly journals The Essential WD Repeat Protein Swd2 Has Dual Functions in RNA Polymerase II Transcription Termination and Lysine 4 Methylation of Histone H3

2004 ◽  
Vol 24 (7) ◽  
pp. 2932-2943 ◽  
Author(s):  
Hailing Cheng ◽  
Xiaoyuan He ◽  
Claire Moore
Keyword(s):  
Rna Polymerase ◽  
Rna Polymerase Ii ◽  
Chromatin Modification ◽  
Histone H3 ◽  
Temperature Sensitive ◽  
Repeat Protein ◽  
Tightly Coupled ◽  
Cleavage And Polyadenylation ◽  
Wd Repeat

ABSTRACT Swd2, an essential WD repeat protein in Saccharomyces cerevisiae, is a component of two very different complexes: the cleavage and polyadenylation factor CPF and the Set1 methylase, which modifies lysine 4 of histone H3 (H3-K4). It was not known if Swd2 is important for the function of either of these entities. We show here that, in extract from cells depleted of Swd2, cleavage and polyadenylation of the mRNA precursor in vitro are completely normal. However, temperature-sensitive mutations or depletion of Swd2 causes termination defects in some genes transcribed by RNA polymerase II. Overexpression of Ref2, a protein previously implicated in snoRNA 3′ end formation and Swd2 recruitment to CPF, can rescue the growth and termination defects, indicating a functional interaction between the two proteins. Some swd2 mutations also significantly decrease global H3-K4 methylation and cause other phenotypes associated with loss of this chromatin modification, such as loss of telomere silencing, hydroxyurea sensitivity, and alterations in repression of INO1 transcription. Even though the two Swd2-containing complexes are both localized to actively transcribed genes, the allele specificities of swd2 defects suggest that the functions of Swd2 in mediating RNA polymerase II termination and H3-K4 methylation are not tightly coupled.

scholarly journals Crystal structure of Ski8p, a WD-repeat protein with dual roles in mRNA metabolism and meiotic recombination

2009 ◽  
Vol 13 (10) ◽  
pp. 2673-2684 ◽  
Author(s):  
Zhihong Cheng ◽  
Yuying Liu ◽  
Chernhoe Wang ◽  
Roy Parker ◽  
Haiwei Song
Keyword(s):  
Crystal Structure ◽  
Meiotic Recombination ◽  
Dual Roles ◽  
Repeat Protein ◽  
Mrna Metabolism ◽  
Wd Repeat

scholarly journals The Novel WD-repeat Protein Morg1 Acts as a Molecular Scaffold for Hypoxia-inducible Factor Prolyl Hydroxylase 3 (PHD3)

2006 ◽  
Vol 281 (13) ◽  
pp. 8645-8655 ◽  
Author(s):  
Ulrike Hopfer ◽  
Helmut Hopfer ◽  
Katarina Jablonski ◽  
Rolf A. K. Stahl ◽  
Gunter Wolf
Keyword(s):  
Hypoxia Inducible Factor ◽  
Prolyl Hydroxylase ◽  
The Novel ◽  
Molecular Scaffold ◽  
Repeat Protein ◽  
Wd Repeat

scholarly journals A WD-Repeat Protein Stabilizes ORC Binding to Chromatin

2010 ◽  
Vol 40 (1) ◽  
pp. 99-111 ◽  
Author(s):  
Zhen Shen ◽  
Kizhakke M. Sathyan ◽  
Yijie Geng ◽  
Ruiping Zheng ◽  
Arindam Chakraborty ◽  
...  
Keyword(s):  
Repeat Protein ◽  
Wd Repeat

scholarly journals A Novel WD Repeat Protein Component of the Methylosome Binds Sm Proteins

2001 ◽  
Vol 277 (10) ◽  
pp. 8243-8247 ◽  
Author(s):  
Westley J. Friesen ◽  
Anastasia Wyce ◽  
Sergey Paushkin ◽  
Linda Abel ◽  
Juri Rappsilber ◽  
...  
Keyword(s):  
Protein Component ◽  
Sm Proteins ◽  
Repeat Protein ◽  
Wd Repeat

scholarly journals Tau tubulin kinase is required for spermatogenesis and development of motile cilia in planarian flatworms

2019 ◽  
Vol 30 (17) ◽  
pp. 2155-2170 ◽  
Author(s):  
Robert Alan Magley ◽  
Labib Rouhana
Keyword(s):  
Intracellular Signaling ◽  
Primary Cilia ◽  
Testicular Tissue ◽  
Structural Defects ◽  
Apical Surface ◽  
Transmission Electron ◽  
Sperm Development ◽  
Associated Proteins ◽  
Motile Cilia ◽  
Reproductive Processes

Cilia are microtubule-based structures that protrude from the apical surface of cells to mediate motility, transport, intracellular signaling, and environmental sensing. Tau tubulin kinases (TTBKs) destabilize microtubules by phosphorylating microtubule-associated proteins (MAPs) of the MAP2/Tau family, but also contribute to the assembly of primary cilia during embryogenesis. Expression of TTBKs is enriched in testicular tissue, but their relevance to reproductive processes is unknown. We identified six TTBK homologues in the genome of the planarian Schmidtea mediterranea ( Smed-TTBK-a, -b, -c, -d, -e, and -f), all of which are preferentially expressed in testes. Inhibition of TTBK paralogues by RNA interference (RNAi) revealed a specific requirement for Smed-TTBK-d in postmeiotic regulation of spermatogenesis. Disrupting expression of Smed-TTBK-d results in loss of spermatozoa, but not spermatids. In the soma, Smed-TTBK-d RNAi impaired the function of multiciliated epidermal cells in propelling planarian movement, as well as the osmoregulatory function of protonephridia. Decreased density and structural defects of motile cilia were observed in the epidermis of Smed-TTBK-d(RNAi) by phase contrast, immunofluorescence, and transmission electron microscopy. Altogether, these results demonstrate that members of the TTBK family of proteins are postmeiotic regulators of sperm development and also contribute to the formation of motile cilia in the soma.

scholarly journals IC138 Is a WD-Repeat Dynein Intermediate Chain Required for Light Chain Assembly and Regulation of Flagellar Bending

2004 ◽  
Vol 15 (12) ◽  
pp. 5431-5442 ◽  
Author(s):  
Triscia W. Hendrickson ◽  
Catherine A. Perrone ◽  
Paul Griffin ◽  
Kristin Wuichet ◽  
Joshua Mueller ◽  
...  
Keyword(s):  
Light Chain ◽  
Beat Frequency ◽  
Wild Type ◽  
Central Pair ◽  
Flagellar Beat ◽  
C Terminus ◽  
Dynein Intermediate Chain ◽  
Radial Spokes ◽  
Calculated Mass ◽  
Wd Repeat

Increased phosphorylation of dynein IC IC138 correlates with decreases in flagellar microtubule sliding and phototaxis defects. To test the hypothesis that regulation of IC138 phosphorylation controls flagellar bending, we cloned the IC138 gene. IC138 encodes a novel protein with a calculated mass of 111 kDa and is predicted to form seven WD-repeats at the C terminus. IC138 maps near the BOP5 locus, and bop5-1 contains a point mutation resulting in a truncated IC138 lacking the C terminus, including the seventh WD-repeat. bop5-1 cells display wild-type flagellar beat frequency but swim slower than wild-type cells, suggesting that bop5-1 is altered in its ability to control flagellar waveform. Swimming speed is rescued in bop5-1 transformants containing the wild-type IC138, confirming that BOP5 encodes IC138. With the exception of the roadblock-related light chain, LC7b, all the other known components of the I1 complex, including the truncated IC138, are assembled in bop5-1 axonemes. Thus, the bop5-1 motility phenotype reveals a role for IC138 and LC7b in the control of flagellar bending. IC138 is hyperphosphorylated in paralyzed flagellar mutants lacking radial spoke and central pair components, further indicating a role for the radial spokes and central pair apparatus in control of IC138 phosphorylation and regulation of flagellar waveform.

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