Inhibition of muscle tropomyosin polymerization by DNAse I

Payne, Michael R.; Rudnick, Suzanne E.

doi:10.1007/bf01116539

Cited by 4 publications

(4 citation statements)

References 22 publications

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“…DNAse I binds muscle and non-muscle tropomyosin, forming a 2:l complex of DNAse I to muscle tropomyosin (30,31). However, G-actin-DNAse I interactions do not appear to be altered by tropomyosin (17,30). This seems to indicate that DNAse I has different binding sites for G-actin and tropomyosin or a significantly reduced relative affinity for tropomyosin.…”

Section: A B C D E a B C D E A B C D Ementioning

confidence: 54%

“…Therefore, because of the abundance of actin in endothelial cells, both the G-and Fforms are stained by this antibody, revealing a pattem similar to that obtained by the simultaneous use of fluorescent DNAse I and phalloidin. DNAse I binds muscle and non-muscle tropomyosin, forming a 2:l complex of DNAse I to muscle tropomyosin (30,31). However, G-actin-DNAse I interactions do not appear to be altered by tropomyosin (17,30).…”

Section: A B C D E a B C D E A B C D Ementioning

confidence: 99%

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Simultaneous visualization of G- and F-actin in endothelial cells.

Haugland¹,

You²,

Paragas³

et al. 1994

J Histochem Cytochem.

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We developed site-specific fluorescent probes that permit simultaneous microscopic observation of G-and Pactin in bovine endothelial cells. Gactin distribution was visualized with fluorescein4eoxyubonuclea.w I (DNAse I). P a c t i n was labeled with phalloidin conjugated to the new longwavelength fluorophore BODIPY 5811591 (581-nm excitation, 591-nm emission), which is spectdy s h h to %as Red. The G-actin appeared as pervasive g m n fluotescence that was more intense in the nuclcar region, where cell thickness is greater and mess fibers are less frequent. In addition, we observed a punctate fluorescein pattem around the nuclei and in other parts of the cells, suggesting that some G-actin is localized to small discrete sites. Pactin was observed as red fluorescent filaments. Unlabeled DNAse I ef-

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Section: A B C D E a B C D E A B C D Ementioning

confidence: 54%

Section: A B C D E a B C D E A B C D Ementioning

confidence: 99%

Simultaneous visualization of G- and F-actin in endothelial cells.

Haugland¹,

You²,

Paragas³

et al. 1994

J Histochem Cytochem.

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“…G-Actin which has been denatured does not inhibit DNase L 18) and TM is known not to interfere with the endonuclease activity of DNase 1. 19 ) Therefore, this assay is well recognized as a sensitive method for quantifying actin denaturation.2.16.20)…”

mentioning

confidence: 99%

Stabilizing Effect of Tropomyosin on Actin during Storage at Low Temperature

Tanji¹,

Ikeuchi

Shimizu³

et al. 1997

Bioscience, Biotechnology, and Biochemistry

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“…DNase I also has been reported to form a 2 : l precipitable complex with muscle tropomyosin [7]. DNase I interferes with the ability of tropomyosin to form head-to-tail polymers in low ionic strength solutions, but tropomyosin does not interfere with the cndonuclease activity of DNase I [8]. As actin and tropomyosin affect DNase I activity differently, DNase I may possess two different sites for interaction with these two microfilament proteins.…”

mentioning

confidence: 99%

Interaction of muscle and non‐muscle tropomyosins with deoxyribonuclease I

Clark

Burtnick

1989

European Journal of Biochemistry

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The sulfhydryl-selective fluorescent reagent acrylodan (6-acryloyl-2-dimethylaminonaphthalene) was used to label tropomyosins from rabbit cardiac muscle and from equine platelets. Addition of bovine pancreatic deoxyribonuclease I to solutions of acrylodan-modified tropomyosins significantly altered the emission properties of the samples. Muscle and non-muscle tropomyosin fluorescence were affected in qualitatively similar manners; emission maxima were red-shifted by about 8 nm to 522 -525 nm and maximal intensities were reduced by approximately 15%. Addition of KI to each of the fluorescent samples caused a greater degree of fluorescence quenching in the presence of DNase I than in its absence. The slopes of Stern-Volmer plots were 15 -25% steeper in the presence of DNase I. Fluorescence polarization values for acrylodan-labelled tropomyosin samples were 25 -35% lower in the presence of DNase I. Each of these effects could be saturated by addition of about a twofold molar excess of DNase I to tropomyosin. Together they suggest that interaction with DNase I causes localized unfolding of tropomyosin, thereby allowing the fluorescent label to become more exposed to the solvent and less restricted in its local motions. Circular dichroism measurements support this idea. Addition of DNase I to solutions of either labelled or unlabelled tropomyosin results in a net 14-18% loss in ellipticity near 220 nm, indicative of unfolding of a-helix.Tropomyosin from muscle sources is a highly a-helical protein that consists of two polypeptide chains, each of 284 amino acid residues, wound around each other to form a rod some 41 nm long (reviewed in [I] and [2]). Non-muscle tropomyosins resemble closely their muscle counterparts in amino acid composition and structure, but may differ significantly in the length of the constituent polypeptide chains (reviewed in [3] and [4]). For example, the P-chain of equine platelet tropomyosin is 247 residues long [5].Bovine pancreatic deoxyribonuclease I (DNase I) is an endonuclease, the activity of which can be inhibited entirely by complex formation with monomeric actin [6]. DNase I also has been reported to form a 2 : l precipitable complex with muscle tropomyosin [7]. DNase I interferes with the ability of tropomyosin to form head-to-tail polymers in low ionic strength solutions, but tropomyosin does not interfere with the cndonuclease activity of DNase I [8]. As actin and tropomyosin affect DNase I activity differently, DNase I may possess two different sites for interaction with these two microfilament proteins.We have previously reacted the sulfhydryl-selective and environment-sensitive fluorescent reagent acrylodan (6-acryloyl-2-dimethylaminonaphthalene) with the sulfhydryl groups at Cysl90 of cardiac tropomyosin and with Cys246 (the penultimate residue) and, to a lesser degree, Cys153 homologous with Cysl90 of muscle tropomyosins) of equinc platelet tropomyosin [9]. We here report data from studies on the effects of addition of DNase I to solutions that contain acrylodan-labelled trop...

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Inhibition of muscle tropomyosin polymerization by DNAse I

Cited by 4 publications

References 22 publications

Simultaneous visualization of G- and F-actin in endothelial cells.

Simultaneous visualization of G- and F-actin in endothelial cells.

Stabilizing Effect of Tropomyosin on Actin during Storage at Low Temperature

Interaction of muscle and non‐muscle tropomyosins with deoxyribonuclease I

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