Microleakage of Four Pulp Protection Agents Placed in Vivo Under Class V amalgam Restorations1

A hallmark of class-V myosins is their processivity—the ability to take multiple steps along actin filaments without dissociating. Our previous work suggested, however, that the fission yeast myosin-V (Myo52p) is a nonprocessive motor whose activity is enhanced by tropomyosin (Cdc8p). Here we investigate the molecular mechanism and physiological relevance of tropomyosin-mediated regulation of Myo52p transport, using a combination of in vitro and in vivo approaches. Single molecules of Myo52p, visualized by total internal reflection fluorescence microscopy, moved processively only when Cdc8p was present on actin filaments. Small ensembles of Myo52p bound to a quantum dot, mimicking the number of motors bound to physiological cargo, also required Cdc8p for continuous motion. Although a truncated form of Myo52p that lacked a cargo-binding domain failed to support function in vivo, it still underwent actin-dependent movement to polarized growth sites. This result suggests that truncated Myo52p lacking cargo, or single molecules of wild-type Myo52p with small cargoes, can undergo processive movement along actin-Cdc8p cables in vivo. Our findings outline a mechanism by which tropomyosin facilitates sorting of transport to specific actin tracks within the cell by switching on myosin processivity.

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Short-term assessment of leakage of class V composite restorations placed in vivo

Clinical Oral Investigations ◽

10.1007/s007840050012 ◽

1997 ◽

Vol 1 (2) ◽

pp. 61-64 ◽

Cited By ~ 4

Author(s):

M. Ferrari ◽

Francesco Mannocci ◽

Maria Crysanti Cagidiaco ◽

Gerard Kugel

Keyword(s):

Short Term ◽

Class V ◽

Composite Restorations

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Complex Formation with Ypt11p, a rab-Type Small GTPase, Is Essential To Facilitate the Function of Myo2p, a Class V Myosin, in Mitochondrial Distribution in Saccharomyces cerevisiae

Molecular and Cellular Biology ◽

10.1128/mcb.22.22.7744-7757.2002 ◽

2002 ◽

Vol 22 (22) ◽

pp. 7744-7757 ◽

Cited By ~ 105

Author(s):

Takashi Itoh ◽

Akiko Watabe ◽

Akio Toh-e ◽

Yasushi Matsui

Keyword(s):

Saccharomyces Cerevisiae ◽

Complex Formation ◽

Mutational Analysis ◽

Small Gtpase ◽

Tail Domain ◽

Class V ◽

Synthetic Lethal ◽

Partial Delay ◽

Mitochondrial Distribution

ABSTRACT We identified Ypt11p, a rab-type small GTPase, by its functional and two-hybrid interaction with Myo2p, a class V myosin of the budding yeast Saccharomyces cerevisiae. The tail domain of Myo2p was coimmunoprecipitated with Ypt11p, suggesting that Ypt11p forms a complex with Myo2p at its tail domain in vivo. Mutational analysis of YPT11 suggests that Myo2p is a putative effector of Ypt11p. Deletion of YPT11 induced partial delay of mitochondrial transmission to the bud, and overexpression of YPT11 resulted in mitochondrial accumulation in the bud, indicating that Ypt11p acts positively on mitochondrial distribution toward the bud. We isolated two myo2 mutants, myo2-338 and myo2-573, which showed genetic interactions with YPT11. The myo2-573 mutation, identified by a synthetic lethal interaction with ypt11-null, induced a defect in mitochondrial distribution toward the bud, indicating that Myo2p plays a crucial role in polarized distribution of mitochondria. The myo2-338 mutation was identified as the mutation that abolished the effect of overexpressed YPT11, such as the Ypt11p-dependent accumulation of mitochondria in the bud, and the affinity of Myo2p for Ypt11p was reduced. These results indicate that complex formation of Ypt11p with Myo2p accelerates the function of Myo2p for mitochondrial distribution toward the bud.

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In Vivo Pulp Temperature Changes During Class V Cavity Preparation and Resin Composite Restoration in Premolars

Operative Dentistry ◽

10.2341/20-098-c ◽

2021 ◽

Author(s):

DC Zarpellon ◽

P Runnacles ◽

C Maucoski ◽

DJ Gross ◽

U Coelho ◽

...

Keyword(s):

Repeated Measures ◽

High Speed ◽

Resin Composite ◽

Bonding Layer ◽

Water Spray ◽

Cavity Preparation ◽

Class V ◽

Diamond Bur ◽

Pulp Temperature

SUMMARY Objective: This in vivo study evaluated the influence of the sequence of all restorative steps during Class V preparation and restoration in human premolars on pulp temperature (PT). Methods and Materials: Intact premolars with orthodontic extraction indication of 13 volunteers received infiltrative anesthesia and isolation with rubber dam. An occlusal preparation was made with a high-speed diamond bur under air-water spray until the pulp was minimally exposed, then a thermocouple probe was inserted within the pulp. A deep, 2.0-mm depth Class V preparation was made using a high-speed diamond bur under air-water spray. Three restorative techniques were performed (n=7): Filtek Z250 placed in two increments (10-second exposure, shade:A2, 3M ESPE, St. Paul, MN, USA), Filtek Z350 XT (40-second exposure, shade:A3D, 3M ESPE) and Tetric N Ceram Bulk Fill (10-second exposure, shade:IVA, Ivoclar Vivadent, Schaan, Liechtenstein), both placed in a single layer. Bonding layer and resin composite were exposed to light from the same Polywave LCU (Bluephase 20i, Ivoclar Vivadent). The peak PT and the difference between peak PT and baseline (ΔT) values were subjected to two-way, repeated measures analysis of variance (ANOVA), followed by the Bonferroni post-hoc test (α=0.05). Results: Cavity preparation and etch & rinse procedures decreased the PT values (p<0.001). The 40-second exposure of Filtek Z350 caused the highest peak PT values (38.7±0.8°C) and the highest ΔT values (3.4±0.8°C), while Tetric N Ceram Bulk Fill showed the lowest values (−1.6±1.3°C; p=0.009). Conclusion: None of the evaluated procedures resulted in a PT rise near to values that could offer any risk of thermal damage to the pulp.

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Mutagenesis and Chemical Cross-Linking Suggest that Wzz Dimer Stability and Oligomerization Affect Lipopolysaccharide O-Antigen Modal Chain Length Control

Journal of Bacteriology ◽

10.1128/jb.01134-09 ◽

2010 ◽

Vol 192 (13) ◽

pp. 3385-3393 ◽

Cited By ~ 22

Author(s):

Magdalene Papadopoulos ◽

Renato Morona

Keyword(s):

Chain Length ◽

Shigella Flexneri ◽

Three Dimensional ◽

Class Ii ◽

Cross Linking ◽

Wild Type ◽

Class V ◽

O Antigen ◽

Class Iv

ABSTRACT In Shigella flexneri, the polysaccharide copolymerase (PCP) protein WzzSF confers a modal length of 10 to 17 repeat units (RUs) to the O-antigen (Oag) component of lipopolysaccharide (LPS). PCPs form oligomeric structures believed to be related to their function. To identify functionally important regions within WzzSF, random in-frame linker mutagenesis was used to create mutants with 5-amino-acid insertions (termed Wzzi proteins), and DNA sequencing was used to locate the insertions. Analysis of the resulting LPS conferred by Wzzi proteins identified five mutant classes. The class I mutants were inactive, resulting in nonregulated LPS Oag chains, while classes II and III conferred shorter LPS Oag chains of 2 to 10 and 8 to 14 RUs, respectively. Class IV mutants retained near-wild-type function, and class V mutants increased the LPS Oag chain length to 16 to 25 RUs. In vivo formaldehyde cross-linking indicated class V mutants readily formed high-molecular-mass oligomers; however, class II and III Wzzi mutants were not effectively cross-linked. Wzz dimer stability was also investigated by heating cross-linked oligomers at 100°C in the presence of SDS. Unlike the WzzSF wild type and class IV and V Wzzi mutants, the class II and III mutant dimers were not detectable. The location of each insertion was mapped onto available PCP three-dimensional (3D) structures, revealing that class V mutations were most likely located within the inner cavity of the PCP oligomer. These data suggest that the ability to produce stable dimers may be important in determining Oag modal chain length.

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Small teams of myosin Vc coordinate their stepping for efficient cargo transport on actin bundles

10.1101/106658 ◽

2017 ◽

Author(s):

Elena B. Krementsova ◽

Ken’ya Furuta ◽

Kazuhiro Oiwa ◽

Kathleen M. Trybus ◽

M. Yusuf Ali

Keyword(s):

Actin Filaments ◽

Myosin Isoforms ◽

Back Side ◽

Dna Nanostructures ◽

Class V ◽

Actin Bundles ◽

Directional Motion ◽

Myosin Va ◽

Run Lengths

AbstractMyosin Vc (myoVc) is unique among vertebrate class V myosin isoforms in that it requires teams of motors to transport cargo. Single molecules of myoVc cannot take multiple steps on single actin filaments, in stark contrast to the well-studied myosin Va (myoVa) isoform. Consistent with in vivo studies (1), only teams of myoVc motors can move continuously on actin bundles at physiologic ionic strength (2), raising the question of how motor motor interactions cause this preference. Here, using DNA nanostructures as synthetic cargos for linking defined numbers of myoVa or myoVc molecules, we compared the stepping behavior of myoVa versus myoVc teams, and myoVc stepping patterns on single actin filaments versus actin bundles. Run lengths of both myoVa and myoVc teams increased with motor number, but the run lengths of myoVc teams were longer on actin bundles than on filaments. By resolving the stepping behavior of individual myoVc motors with a Qdot bound to the motor domain, we found that coupling of two myoVc molecules significantly decreases futile back/side steps, which were frequently observed for single myoVc motors. Data showing how changes in the inter-motor distance of two coupled myoVc motors affected stepping dynamics suggested that mechanical tension coordinates the stepping behavior of two molecules for efficient directional motion. Our study thus provides a molecular basis to explain how teams of myoVc motors are suited to transport cargos such as zymogen granules on actin bundles.AbbreviationsMyoVcMyosin VcmyoVaMyosin VaQdotsQuantum dotsSDStandard DeviationSEStandard ErrorDNAdeoxyribonucleic acid

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