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Reisen, Daniel; Hanson, Maureen R.

doi:10.1186/1471-2229-7-6

Cited by 97 publications

(41 citation statements)

References 49 publications

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“…Thus, our results proved that the globular tail is sufficient for organelle binding in class XI myosins as in class V myosins. Interestingly, a recent study employing YFP fusions to various truncations of several myosin XI proteins did not find reliable labeling of organelles with shorter constructs although some distinct spots were seen for a shortened YFP-MYA1 globular tail construct (21). We speculate that this discrepancy to our results stems from the use of different fusion sites.…”

Section: The Globular Tail Of Myosin XI Is Sufficient For Organelle Tcontrasting

confidence: 98%

“…4 and 5). The localization of MYA2 globular tail constructs to peroxisomes and unknown organelles in this study agrees with previous reports based on antibody or YFP labeling (20,21). Thus, our results proved that the globular tail is sufficient for organelle binding in class XI myosins as in class V myosins.…”

Section: The Globular Tail Of Myosin XI Is Sufficient For Organelle Tsupporting

confidence: 93%

“…5E). Localization of MYA2 subdomains to small organelles or peroxisomes, respectively, is fully consistent with the distribution of immunodetected native protein (20) and YFP-labeled tail constructs (21). None of these constructs prevented movement of the targeted organelles (data not shown), which is similar to the lack of a dominant negative effect of other YFP-tail fusions described previously (21).…”

Section: Myosin XI Tail Subdomains Interact With Each Other In Yeastsupporting

confidence: 87%

“…First, disruption of organelle movements in plant cells by anti-actin drug or myosin ATPase inhibitor treatment strongly indicated that organelle motility depends on both actin and myosin (12)(13)(14)(15)(16). Second, myosin XI was found to associate with a diverse array of organelles in plant cells by immunostaining (17)(18)(19)(20), YFP labeling (21), and co-purification studies (22). Finally, there is an overall structural similarity between class XI and class V myosins, the latter being responsible for organelle movement in fungi and animals (23).…”

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confidence: 99%

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Organelle Targeting of Myosin XI Is Mediated by Two Globular Tail Subdomains with Separate Cargo Binding Sites

Nebenführ

2007

Journal of Biological Chemistry

138

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Myosin XI are actin-based molecular motors that are thought to drive organelle movements in plants, analogous to myosin V in animals and fungi. Similar domain structure of these myosins suggests that binding to organelles may occur via the globular tail domain in both types of motors, even though sequence similarity is low. To address this hypothesis, we developed a structure homology model for the globular tail of MYA1, a myosin XI from Arabidopsis, based on the known structure of yeast myosin V (Myo2p) globular tail. This model suggested an interaction between two subdomains of the globular tail which was verified by yeast two-hybrid assay and by in vivo bimolecular fluorescence complementation (BiFC). Interface mapping demonstrated that this subdomain interaction depends critically on the C terminus of helix H6 as well as three specific residues in helices H3 and H15, consistent with the structural prediction. The reconstituted globular tails of several Arabidopsis myosin XIs in BiFC assays targeted to peroxisomes in plant cells, identifying this domain as sufficient for cargo binding. Unlike myosin V, either subdomain of myosin XI alone was targeting-competent and responsible for association with different organelles. In addition, our data suggest that organelle binding is regulated by an allosteric interaction between two tail subdomains. We conclude that the globular tail of myosin XI shares a similar structure with that of myosin V, but has evolved plant-specific cargo binding mechanisms.Myosins are efficient molecular motor proteins which convert chemical energy from ATP hydrolysis to physical force to move along cytoskeletal actin filaments (1). Based on sequence comparison of myosin motor domains, these nearly ubiquitous eukaryotic motors can be grouped into 24 subfamilies designated as class I to XXIV (2). Plants from green algae to flowering plants encode only two classes, myosin VIII and XI (3). A number of myosin XI isoforms have been identified from a variety of organisms by biochemical isolation (4, 5), molecular cloning (6 -8), or genome-wide sequence analysis (9, 10). Little is known about the specific cellular function of class XI myosins in plants, but it is generally assumed that they are responsible for force generation for organelle transport during cytoplasmic streaming (11).This assumption is based on three lines of evidence. First, disruption of organelle movements in plant cells by anti-actin drug or myosin ATPase inhibitor treatment strongly indicated that organelle motility depends on both actin and myosin (12-16). Second, myosin XI was found to associate with a diverse array of organelles in plant cells by immunostaining (17-20), YFP labeling (21), and co-purification studies (22). Finally, there is an overall structural similarity between class XI and class V myosins, the latter being responsible for organelle movement in fungi and animals (23). In particular: (i) both classes have the same domain arrangement, including a catalytic motor in the head, six copies of calmodulin bindin...

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Section: The Globular Tail Of Myosin XI Is Sufficient For Organelle Tcontrasting

confidence: 98%

Section: The Globular Tail Of Myosin XI Is Sufficient For Organelle Tsupporting

confidence: 93%

Section: Myosin XI Tail Subdomains Interact With Each Other In Yeastsupporting

confidence: 87%

mentioning

confidence: 99%

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Organelle Targeting of Myosin XI Is Mediated by Two Globular Tail Subdomains with Separate Cargo Binding Sites

Nebenführ

2007

Journal of Biological Chemistry

138

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“…It is interesting to note that two recent studies on myosin XI function show a requirement of their C-terminal tail domain together with the coiled-coil domain for correct localization of myosin fragments (37,38). These results suggest that myosin XI-dependent cargocomplex assembly may uses a mechanism related to the Myo4p and She3p interaction.…”

Section: Regulation Of Motor-complex Assembly In Higher Eukaryotesmentioning

confidence: 92%

Monomeric myosin V uses two binding regions for the assembly of stable translocation complexes

Heuck

Jellbauer

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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Myosin-motors are conserved from yeast to human and transport a great variety of cargoes. Most plus-end directed myosins, which constitute the vast majority of all myosin motors, form stable dimers and interact constitutively with their cargo complexes. To date, little is known about regulatory mechanisms for cargocomplex assembly. In this study, we show that the type V myosin Myo4p binds to its cargo via two distinct binding regions, the C-terminal tail and a coiled-coil domain-containing fragment. Furthermore, we find that Myo4p is strictly monomeric at physiologic concentrations. Because type V myosins are thought to require dimerization for processive movement, a mechanism must be in place to ensure that oligomeric Myo4p is incorporated into cargotranslocation complexes. Indeed, we find that artificial dimerization of the Myo4p C-terminal tail promotes stabilization of myosincargo complexes, suggesting that full-length Myo4p dimerizes in the cocomplex as well. We also combined the Myo4p C-terminal tail with the coiled-coil region, lever arm, and motor domain from a different myosin to form constitutively dimeric motor proteins. This heterologous motor successfully translocates its cargo in vivo, suggesting that wild-type Myo4p may also function as a dimer during cargo-complex transport.cell asymmetry ͉ Myo4p ͉ RNA localization ͉ She3p ͉ motor protein

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The Dynamic Chondriome

Logan

Paszkiewicz

2017

Annual Plant Reviews, Volume 50

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Untitled

Cited by 97 publications

References 49 publications

Organelle Targeting of Myosin XI Is Mediated by Two Globular Tail Subdomains with Separate Cargo Binding Sites

Organelle Targeting of Myosin XI Is Mediated by Two Globular Tail Subdomains with Separate Cargo Binding Sites

Monomeric myosin V uses two binding regions for the assembly of stable translocation complexes

The Dynamic Chondriome

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