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Plant Intracellular Transport: Tracing Functions of the Retrograde Kinesin View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Current Biology Dispatches organs) the ants did not respond study by Hojo et al. [2], it seems that attendant ant behavior. Curr. Biol. 25, aggressively. attending bodyguard ants are less likely to 2260–2264. Not only were the behaviors of the wander from their charge and more 3. Ho¨ lldobler, B., and Wilson, E.O. (2009). attendant ants changed but also likely to be aggressive, which should The superorganism: the beauty, elegance, and strangeness of insect societies (W.W. Norton). dopamine levels in their brains, which benefit the caterpillar. This ‘mutualism’ increased significantly in ants that thus has all the hallmarks of adaptive 4. Ho¨ lldobler, B., and Wilson, E.O. (1990). The Ants (Cambridge, Mass.: Harvard University attended caterpillars with functioning manipulation of host behavior by a Press). nectary organs. Other biogenic amines parasite! (serotonin, octopamine and tyramine) It would appear that caterpillars enforce 5. Davidson, D.W., Cook, S.C., Snelling, R.R., and Chua, T.H. (2003). Explaining the were not affected. Exactly how the the cooperation they require. This is likely abundance of ants in lowland tropical secretions from the nectary organs could to be due to the fact that the ant colony rainforest canopies. Science 300, 969–972. elicit such changes in an important may not need its caterpillar ‘sugar tap’ as 6. Pierce, N.E., and Mead, P.S. (1981). neuromodulator and neurotransmitter much as the sugar tap needs its fierce Parasitoids as selective agents in the remains unknown. The quantity of bodyguards. As other sources of sugar symbiosis between lycaenid butterfly larvae and ants. Science 211, 1185–1187. secretions from the nectary organs is very present themselves, the danger for the small, making a complete chemical caterpillar is that the ants shift away from 7. Pierce, N.E. (1995). Predatory and parasitic Lepidoptera: carnivores living on plants. characterization difficult. In addition, the their protective role, leaving the caterpillar J. Lepid. Soc. 49, 412–453. researchers only measured four biogenic vulnerable to predation. And so, perhaps 8. Als, T.D., Vila, R., Kandul, N.P., Nash, D.R., amines, but other changes in the brains of by way of an insurance mechanism, the Yen, S.H., Hsu, Y.F., Mignault, A.A., attendant ants might be taking place. hungry caterpillar has evolved to keep Boomsma, J.J., and Pierce, N.E. (2004). The Hopefully, future work such as whole their ant bodyguards on a short leash evolution of alternative parasitic life histories in large blue butterflies. Nature 432, 386–390. brain metabolomics or RNA-seq using manipulative drugs. This study will experiments on individual brains will hopefully encourage different researchers 9. Pierce, N.E., Braby, M.F., Heath, A., Lohman, D.J., Mathew, J., Rand, D.B., and Travassos, provide further insights. to examine other apparent manipulations M.A. (2002). The ecology and evolution of ant But the importance of this paper is not for signs of similar manipulative association in the Lycaenidae (Lepidoptera). just for the details it provides on the behaviors. Annu. Rev. Entomol. 47, 733–771. proximate mechanisms of behavioral 10. Hojo, M.K., Yamamoto, A., Akino, T., Tsuji, K., manipulation [11]. The importance is also and Yamaoka, R. (2014). Ants use partner REFERENCES specific odors to learn to recognize a that apparently mutualistic caterpillars mutualistic partner. PLoS One 9, e86054. manipulate ant behavior at all. It is well known that parasites can adaptively 1. Rico-Gray, V., and Oliveira, P.S. (2007). The 11. Hughes, D.P. (2013). Pathways to Ecology and Evolution of Ant-Plant understanding the extended phenotype of manipulate the behavior of their hosts. Interactions (Chicago: University of Chicago parasites in their hosts. J. Exp. Biol. 216, This is the concept of the extended Press). 142–147. phenotype [12], where changes in host 2. Hojo, M.K., Pierce, N.E., and Tsuji, K. (2015). 12. Dawkins, R. (1982). The extended phenotype behavior benefit parasite fitness. In the Lycaenid caterpillar secretions manipulate (Oxford: W.H. Freeman). Plant Intracellular Transport: Tracing Functions of the Retrograde Kinesin Sabine Mu¨ ller ZMPB, University of Tu¨ bingen, Morganstelle 32, 72026, Tu¨ bingen, Germany Correspondence: [email protected] http://dx.doi.org/10.1016/j.cub.2015.08.011 Adding to its varied repertoire of functions in cell morphogenesis and cell division, a molecular motor protein of the kinesin-14 class has recently been implicated in rapid retrograde transport along cellular tracks in moss. Like traffic in general, cellular trafficking are made of the cytoskeleton — polar cytoskeleton is nearly infinite, and also relies on dedicated tracks and microtubules and actin filaments. Aided includes diverse functions in cell division, vehicles that facilitate the transport of by versatile molecular motors, the list cell polarization and growth as well as in cargo. In all eukaryotes, transport tracks of cellular mechanisms requiring the subcellular transport. In most eukaryotes, R808 Current Biology 25, R793–R810, September 21, 2015 ª2015 Elsevier Ltd All rights reserved Current Biology Dispatches cargo transport along these cellular tracks presence of a small number of attributed to the plant specific mode of is assisted by three motor protein processively moving kin-14VIb. This division plane positioning [8]. Plant cells families — the microtubule-dependent processive movement originated from are immobilized within tissues due to their kinesins, the dyneins and the the clustering of two or more kin-14VIb confinement by cell walls; therefore, actin-dependent myosins. However, the dimers, akin to the processive movement spatio-temporal control over cell divisions microtubule minus-end directed dyneins of an artificial kin-14VIb tetramer [2].In is crucial for plant development. Plant were lost from flowering plants and are support of the notion that the processive cells do not divide by constriction, absent from most clades of the lower behavior of kin-14VIb depended on but instead form a new partitioning wall, plants [1], raising the question of multiple motor dimers, clustering of the cell plate, in the cell center during exactly how plant cells accomplish kin-14VIb on liposomes enabled liposome cytokinesis. KCBP was recently minus-end directed, retrograde transport along microtubules [2]. implicated in the guidance mechanism microtubule-dependent transport. Finally, fluorescently labeled, that attracts the cell plate to its final Members of the minus-end directed endogenous kin-14VIb punctae moved destination [8], which is pre-selected kinesin-14 class motor proteins might processively along microtubules in moss prior to mitosis by a transient band of substitute for dynein to achieve retrograde protonemal cells, and comparison of microtubules, the plant-specific transport functions; yet, until recently, signal intensities with protein complexes preprophase band [13]. The preprophase processive motility was only confirmed for of known fluorophore numbers suggested band disassembles, but leaves behind kinesin-14 in yeast, but was reported that the mobile kin-14VIb punctae indeed a set of ‘landmark’ proteins, collectively neither for animal nor plant kinesin-14. contained more than one dimer [2]. referred to as the cortical division site, that In a new study, published recently The authors conclude that the clustering is required to preserve the positional in Nature Plants, [2],Jo¨ nsson and of a few non-processive kin-14VIb information of the preprophase band co-workers now show that a member dimers collectively enables the throughout mitosis [13,14]. The recently of the kinesin-14 class motor proteins in processive microtubule minus-end revealed presence of KCBP at the cortical the moss Physcomitrella patens performs directed movement in the moss. Although division site paves the way for speculation retrograde transport towards the the potential cargos are still elusive, it whether KCBP-mediated forces might minus-end of microtubules. In moss, seems that the search for the retrograde contribute to the unique cell plate the kinesin-14 class encompasses six microtubule-dependent motor has come guidance mechanisms [8]. subdivisions, kin-14I to kin-14VI, and to a closure in the moss. Thus, the kin-14VIb/KCBP based on subcellular localization they However, this finding leads to the microtubule-minus end-directed motors were assigned mitotic and non-mitotic question of which functions kin-14VIb emerge as versatile motor proteins that functions [3]. The authors used advanced motor might have in other plants. Indeed, replace dynein as a retrograde imaging of in vitro microtubule gliding the homologue of kin-14VIb in flowering transporter in the moss, and likely in the assays to visualize the directional plants, kinesin-like calmodulin-binding entire plant lineage, pending proof of displacement of polarity-marked protein (KCBP), has been extensively processive movement. It should be microtubules by purified kinesin-14 studied in vitro and in vivo [4–9]. KCBP noted here that rapid subcellular motors attached to glass cover slips. binding to calcium-calmodulin inhibits transport has been attributed to the Four of the six representative kinesin-14s the motor’s microtubule binding ability actin–myosin cytoskeleton [15]. However, tested displayed microtubule minus-end [10–12] and likely this is also the case plant-specific mitotic KCBP functions directed motility as dimers [2]. To analyze for moss kin-14VIb. Arabidopsis KCBP is might have evolved concurrent with the motors’ processivity in vitro, a minus-end directed motor in vitro [10], the transition from simple to complex single-molecule motility assays were and in cotton KCBP displays punctate plant architecture in the context of cell performed, where labeled microtubules localization along microtubules [7] in wall-imposed positional confinement. were bound to a cover slip and dilute agreement with the findings for moss Consistent with their plant-specific kinesin-14 preparations were added [2]. kin-14VIb [2].
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