Name: aip1p dynamics are altered by the r256h mutation in actin
Uploaded: 2014-07-30T14:00:00
Description: Watch this Scientific Journal Video about Aip1p Dynamics Are Altered by the R256H Mutation in Actin at JoVE.com

The authors thank Peter Rubenstein for useful discussion and technical advice and David Pellman for the original PB1996 clone. This work was supported by a grant from the March of Dimes and funding from the Ride for the Kids.

1. Cloning into the PB1996 Plasmid
<ol>
	<li>Design and order DNA primers from an oligonucleotide manufacturing company that flank the target sequence and contain unique restriction sites in the selected parent plasmid. NOTE: In this case, primers were designed to amplify the 400 base pairs at the 5&#8217; end of the Aip1 sequence. The XhoI restriction site was incorporated into the primer about 20 bp before the Aip1 sequence, and XmaI was included about 20 bp after the target Aip1 sequence. The plasmid used for clonin...

<ol>
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J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Segregation+of+a+missense+variant+in+enteric+smooth+muscle+actin+gamma-2+with+autosomal+dominant+familial+visceral+myopathy.">Segregation of a missense variant in enteric smooth muscle actin gamma-2 with autosomal dominant familial visceral myopathy.</a> Gastroenterology. 143, 1482-1491 (2012).</li><li>Matsson, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alpha-cardiac+actin+mutations+produce+atrial+septal+defects.">Alpha-cardiac actin mutations produce atrial septal defects.</a> Hum Mol Genet. 17, 256-265 (2008).</li><li>Zhu, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mutations+in+the+gamma-actin+gene+(ACTG1)+are+associated+with+dominant+progressive+deafness+(DFNA20/26).">Mutations in the gamma-actin gene (ACTG1) are associated with dominant progressive deafness (DFNA20/26).</a> Am J Hum Genet. 73, 1082-1091 (2003).</li><li>Nowak, K. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mutations+in+the+skeletal+muscle+alpha-actin+gene+in+patients+with+actin+myopathy+and+nemaline+myopathy.">Mutations in the skeletal muscle alpha-actin gene in patients with actin myopathy and nemaline myopathy.</a> Nat Genet. 23, 208-212 (1999).</li><li>Olson, T. M., Michels, V. V., Thibodeau, S. N., Tai, Y. S., Keating, M. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Actin+mutations+in+dilated+cardiomyopathy,+a+heritable+form+of+heart+failure.">Actin mutations in dilated cardiomyopathy, a heritable form of heart failure.</a> Science. 280, 750-752 (1998).</li><li>Riviere, J. 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(44), (2010).</li><li>Spira, F., Dominguez-Escobar, J., Muller, N., Wedlich-Soldner, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visualization+of+cortex+organization+and+dynamics+in+microorganisms,+using+total+internal+reflection+fluorescence+microscopy.">Visualization of cortex organization and dynamics in microorganisms, using total internal reflection fluorescence microscopy.</a> J Vis Exp. (63), e3982 (2012).</li><li>Manneville, J. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+TIRF+microscopy+to+visualize+actin+and+microtubules+in+migrating+cells.">Use of TIRF microscopy to visualize actin and microtubules in migrating cells.</a> Methods Enzymol. 406, 520-532 (2006).</li><li>Cook, R. K., Sheff, D. R., Rubenstein, P. 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A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Overlapping+and+distinct+functions+for+cofilin,+coronin+and+Aip1+in+actin+dynamics+in+vivo.">Overlapping and distinct functions for cofilin, coronin and Aip1 in actin dynamics in vivo.</a> J Cell Sci. 123, 1329-1342 (2010).</li><li>Malloy, L. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thoracic+Aortic+Aneurysm+(TAAD)-causing+Mutation+in+Actin+Affects+Formin+Regulation+of+Polymerization.">Thoracic Aortic Aneurysm (TAAD)-causing Mutation in Actin Affects Formin Regulation of Polymerization.</a> J Biol Chem. 287, 28398-28408 (2012).</li><li>Smyth, J. W., Shaw, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visualizing+ion+channel+dynamics+at+the+plasma+membrane.">Visualizing ion channel dynamics at the plasma membrane.</a> Heart Rhythm. 5, S7-S11 (2008).</li><li>Bhattacharya, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recruitment+of+vimentin+to+the+cell+surface+by+beta3+integrin+and+plectin+mediates+adhesion+strength.">Recruitment of vimentin to the cell surface by beta3 integrin and plectin mediates adhesion strength.</a> J Cell Sci. 122, 1390-1400 (2009).</li><li>Hetheridge, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+formin+FMNL3+is+a+cytoskeletal+regulator+of+angiogenesis.">The formin FMNL3 is a cytoskeletal regulator of angiogenesis.</a> J Cell Sci. 125, 1420-1428 (2012).</li><li>Bergeron, S. 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An effective strategy to visualize the dynamics of the cytoskeleton and the utility in investigations on pathogenic mutations has been described here. Advanced imaging modalities have created new opportunities to understand the intracellular movement of proteins near the cell membrane. Total internal reflection fluorescence microscopy (TIRF) is a sensitive technique for functional studies in living cells. TIRF uses an angled excitation laser that creates an evanescent field due to the difference in refractive indexes of ...

Actin is the dominant protein comprising the cytoskeleton and participates in critical cellular processes including cell division, organelle movement, cell motility, contraction, and signaling. Over the past decade, disease-causing mutations in actin have been discovered in each of the six human actin isoforms leading to a range of disorders, from myopathies to coronary artery disease1-7. The processes by which actin mutations lead to disease continue to be elucidated. The yeast model remains the gold standard to study the biochemical effects of mutations on actin function owing to the advantages of the single essential actin isoform, genetic tractability and high conservation of actin sequence and function. Studies show that individual actin mutations lead to molecular specific dysfunctions with dominant negative effects8. For example, deafness-causing mutations in &#947;-non-muscle actin that affect the Lys-118 residue alter regulation by the actin binding protein Arp2/39. Studies frequently employ in vitro analyses of protein: protein interactions. Investigations into the effect of actin mutations on cell biology and, in particular, actin binding protein localization in the cell are limited.
Studies of the yeast cytoskeleton in vivo conventionally rely on images of fixed cells from an inverted fluorescence microscope10. These experiments supplied foundational data about the morphology of the actin cytoskeleton. Investigations have since incorporated three dimensional confocal imaging to visualize the complex cytoskeletal network11,12. This imaging permits quantification of the abundance and relative location of actin patches and filaments. Thin section electron tomography has been used to image the morphology of the dense filamentous networks relative to preserved subcellular structures13. Crowded cellular spaces with a small cross section can be examined in fine detail with this technique. Imaging studies have been extended to living cells using time lapse fluorescent microscopy. When photo bleaching and background fluorescence can be moderated, time lapse imaging allows investigations as to the dynamics of cytoskeletal proteins and the response to environmental conditions11,14. Separately, visualization of the dynamics of actin filaments in vitro was advanced by the introduction of total internal reflection fluorescence (TIRF) microscopy. Compared to wide field microscopy, TIRF has the advantage of decreased background fluorescence and enhanced contrast to monitor individual filaments15,16. With these qualities, TIRF microscopy has been adapted by cell biologists to monitor cellular structures at the plasma membrane17,18. Cellular events, including changes in the cytoskeleton, can be visualized real time with low phototoxicity, maximal contrast, and minimal background florescence19.
To better understand the effect of actin mutations on the movement, localization, and turnover of cytoskeletal proteins in the cell, TIRF microscopy and protein tagging were used. Herein, methods to study the effects of a clinically relevant mutation in actin on cytoskeletal dynamics in Saccharomyces cerevisiae are described. Specifically, the localization and movement of the actin binding protein, Aip1p, was visualized and quantified in cells expressing the R256H mutation in actin. These techniques complement in vitro biochemical studies and allow for a greater understanding of protein interactions and functions.

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			<td height="21" style="height:21px;width:216px;">Agarose</td>
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			<td style="width:119px;">9012-36-6</td>
			<td style="width:167px;"></td>
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			<td height="21" style="height:21px;width:216px;">Bromophenol Blue</td>
			<td style="width:103px;">Amresco</td>
			<td style="width:119px;">115-39-9</td>
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			<td height="21" style="height:21px;width:216px;">BSA</td>
			<td style="width:103px;">NEB</td>
			<td style="width:119px;">B9001S</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Change-IT Multiple Mutation Site Directed Mutagenesis Kit</td>
			<td style="width:103px;">USB Corporation</td>
			<td align="right" style="width:119px;">4166059</td>
			<td></td>
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			<td height="21" style="height:21px;width:216px;">CutSmart Buffer</td>
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			<td height="42" style="height:42px;width:216px;">DNA, single stranded from salmon testes</td>
			<td style="width:103px;">Sigma</td>
			<td style="width:119px;">9007-49-2</td>
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			<td height="21" style="height:21px;width:216px;">EDTA pH 7.4</td>
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			<td height="21" style="height:21px;width:216px;">Ethidium Bromide</td>
			<td style="width:103px;">Invitrogen</td>
			<td style="width:119px;">15585-011</td>
			<td>Warning! Harmful irritation</td>
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			<td height="42" style="height:42px;width:216px;">Fungal/Bacterial DNA Kit</td>
			<td style="width:103px;">Symo Research</td>
			<td style="width:119px;">D6005</td>
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			<td height="21" style="height:21px;width:216px;">HpaI</td>
			<td style="width:103px;">NEB</td>
			<td style="width:119px;">R0105S</td>
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			<td height="21" style="height:21px;width:216px;">Lithium Acetate</td>
			<td style="width:103px;">AlfaAesar</td>
			<td style="width:119px;">6108-17-4</td>
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			<td height="21" style="height:21px;width:216px;">Low DNA Mass Ladder</td>
			<td style="width:103px;">Invitrogen</td>
			<td style="width:119px;">10068-013</td>
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			<td height="21" style="height:21px;width:216px;">NE Buffer #4</td>
			<td style="width:103px;">NEB</td>
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			<td height="42" style="height:42px;width:216px;">Platinum PCR SuperMix High Fidelity</td>
			<td style="width:103px;">Invitrogen</td>
			<td style="width:119px;">12532-016</td>
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			<td height="21" style="height:21px;width:216px;">Miniprep Kit</td>
			<td style="width:103px;">Qiagen</td>
			<td align="right" style="width:119px;">27106</td>
			<td>Any kit will work</td>
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			<td height="21" style="height:21px;width:216px;">Quick Ligation Kit</td>
			<td style="width:103px;">NEB</td>
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			<td height="21" style="height:21px;width:216px;">Sodium azide</td>
			<td style="width:103px;">Sigma</td>
			<td style="width:119px;">26628-22-8</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PBS</td>
			<td style="width:103px;">Invitrogen</td>
			<td style="width:119px;">10010-023</td>
			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PEG</td>
			<td style="width:103px;">Amresco</td>
			<td style="width:119px;">25322-68-3</td>
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			<td height="21" style="height:21px;width:216px;">Tris Base Ultrapure</td>
			<td style="width:103px;">rpi</td>
			<td style="width:119px;">77-86-1</td>
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			<td height="42" style="height:42px;width:216px;">Wizard SV Gel and PCR Clean-Up System</td>
			<td style="width:103px;">Promega</td>
			<td align="right" style="width:119px;">1/6/2015</td>
			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:216px;">XhoI</td>
			<td style="width:103px;">NEB</td>
			<td style="width:119px;">R0146S</td>
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		<tr height="21">
			<td height="21" style="height:21px;width:216px;">XmaI</td>
			<td style="width:103px;">NEB</td>
			<td style="width:119px;">R0180S</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">YPD media</td>
			<td style="width:103px;">LabExpress</td>
			<td align="right" style="width:119px;">3011</td>
			<td></td>
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		<tr height="21">
			<td height="21" style="height:21px;width:216px;">-URA Media</td>
			<td style="width:103px;">LabExpress</td>
			<td align="right" style="width:119px;">3010</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">PCR Machine</td>
			<td style="width:103px;">Invitrogen</td>
			<td align="right" style="width:119px;">4359659</td>
			<td>Any PCR machine will work</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">TIRF Microscope</td>
			<td style="width:103px;">Olympus IX81</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Hamamatsu ORCA-R camera</td>
			<td style="width:103px;">Hamamatsu</td>
			<td style="width:119px;"></td>
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		</tr>
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</table>

aip1p dynamics are altered by the r256h mutation in actin

Mutations in actin cause a range of human diseases due to specific molecular changes that often alter cytoskeletal function. In this study, imaging of fluorescently tagged proteins using total internal fluorescence (TIRF) microscopy is used to visualize and quantify changes in cytoskeletal dynamics. TIRF microscopy and the use of fluorescent tags also allows for quantification of the changes in cytoskeletal dynamics caused by mutations in actin. Using this technique, quantification of cytoskeletal function in live cells valuably complements in vitro studies of protein function. As an example, missense mutations affecting the actin residue R256 have been identified in three human actin isoforms suggesting this amino acid plays an important role in regulatory interactions. The effects of the actin mutation R256H on cytoskeletal movements were studied using the yeast model. The protein, Aip1, which is known to assist cofilin in actin depolymerization, was tagged with green fluorescent protein (GFP) at the N-terminus and tracked in vivo using TIRF microscopy. The rate of Aip1p movement in both wild type and mutant strains was quantified. In cells expressing R256H mutant actin, Aip1p motion is restricted and the rate of movement is nearly half the speed measured in wild type cells (0.88 &#177; 0.30 &#956;m/sec in R256H cells compared to 1.60 &#177; 0.42 &#956;m/sec in wild type cells, p &#60; 0.005).

A method to image the dynamics of cytoskeletal proteins in the cell is presented. The actin-binding protein, Aip1p, was tagged with GFP. The design for the plasmid encoding the tagged product is shown in Figure 1. The plasmid was then transformed into the yeast cells. Expression of the fluorescently tagged Aip1p allowed visualization of the protein behavior in the cell. Aip1p typically localizes to actin patches at sites of endocytosis22. To quantify Aip1p movement, more than 50 fluorescent Ai...

Watch this Scientific Journal Video about Aip1p Dynamics Are Altered by the R256H Mutation in Actin at JoVE.com

Aip1p Dynamics Are Altered by the R256H Mutation in Actin

Disease-causing mutations in actin can alter cytoskeletal function. Cytoskeletal dynamics are quantified through imaging of fluorescently tagged proteins using total internal fluorescence microscopy. As an example, the cytoskeletal protein, Aip1p, has altered localization and movement in cells expressing the mutant actin isoform, R256H.

Mutations in actin cause a range of human diseases due to specific molecular changes that often alter cytoskeletal function. In this study, imaging of ...

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Biology

Actin Co-Sedimentation Assay; for the Analysis of Protein Binding to F-Actin

The actin cytoskeleton within the cell is a network of actin filaments that allows the movement of cells and cellular processes, and that generates ...

Live Cell Imaging of F-actin Dynamics via Fluorescent Speckle Microscopy (FSM)

Live Cell Imaging of F-actin Dynamics via Fluorescent Speckle Microscopy FSM

In this protocol we describe the use of Fluorescent Speckle Microscopy (FSM) to capture high-resolution images of actin dynamics in PtK1 cells. A unique ...

Tracking Dynamics of Muscle Engraftment in Small Animals by In Vivo Fluorescent Imaging

Tracking Dynamics of Muscle Engraftment in Small Animals by In Vivo Fluorescent Imaging

Muscular dystrophies are a group of degenerative muscle diseases characterized by progressive loss of contractile muscle cells. Currently, there is no ...

Photobleaching Assays (FRAP &amp; FLIP) to Measure Chromatin Protein Dynamics in Living Embryonic Stem Cells

Photobleaching Assays FRAP & FLIP to Measure Chromatin Protein Dynamics in Living Embryonic Stem Cells

Fluorescence Recovery After Photobleaching (FRAP) and Fluorescence Loss In Photobleaching (FLIP) enable the study of protein dynamics in living cells with ...

Study of the Actin Cytoskeleton in Live Endothelial Cells Expressing GFP-Actin

The microvascular endothelium plays an important role as a selectively permeable barrier to fluids and solutes. The adhesive junctions between endothelial ...

Selective Capture of 5-hydroxymethylcytosine from Genomic DNA

5-methylcytosine (5-mC) constitutes ~2-8% of the total cytosines in human genomic DNA and impacts a broad range of biological functions, including gene ...

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

In Vivo 4-Dimensional Tracking of Hematopoietic Stem and Progenitor Cells in Adult Mouse Calvarial Bone Marrow

Through a delicate balance between quiescence and proliferation, self renewal and production of differentiated progeny, hematopoietic stem cells (HSCs) ...

Fecal Glucocorticoid Analysis: Non-invasive Adrenal Monitoring in Equids

Adrenal activity can be assessed in the equine species by analysis of feces for corticosterone metabolites. During a potentially aversive situation, ...

High-resolution Time-lapse Imaging and Automated Analysis of Microtubule Dynamics in Living Human Umbilical Vein Endothelial Cells

The physiological process by which new vasculature forms from existing vasculature requires specific signaling events that trigger morphological changes ...

Three-dimensional Super Resolution Microscopy of F-actin Filaments by Interferometric PhotoActivated Localization Microscopy (iPALM)

Three-dimensional Super Resolution Microscopy of F-actin Filaments by Interferometric PhotoActivated Localization Microscopy iPALM

Fluorescence microscopy enables direct visualization of specific biomolecules within cells. However, for conventional fluorescence microscopy, the spatial ...