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Polar delivery in plants; commonalities and differences to animal epithelial cells.

Kania U, Fendrych M, Friml J - Open Biol (2014)

Bottom Line: Although plant and animal cells use a similar core mechanism to deliver proteins to the plasma membrane, their different lifestyle, body organization and specific cell structures resulted in the acquisition of regulatory mechanisms that vary in the two kingdoms.In particular, cell polarity regulators do not seem to be conserved, because genes encoding key components are absent in plant genomes.In animals, much information is provided from the study of polarity in epithelial cells that exhibit basolateral and luminal apical polarities, separated by tight junctions.

View Article: PubMed Central - PubMed

Affiliation: Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria.

ABSTRACT
Although plant and animal cells use a similar core mechanism to deliver proteins to the plasma membrane, their different lifestyle, body organization and specific cell structures resulted in the acquisition of regulatory mechanisms that vary in the two kingdoms. In particular, cell polarity regulators do not seem to be conserved, because genes encoding key components are absent in plant genomes. In plants, the broad knowledge on polarity derives from the study of auxin transporters, the PIN-FORMED proteins, in the model plant Arabidopsis thaliana. In animals, much information is provided from the study of polarity in epithelial cells that exhibit basolateral and luminal apical polarities, separated by tight junctions. In this review, we summarize the similarities and differences of the polarization mechanisms between plants and animals and survey the main genetic approaches that have been used to characterize new genes involved in polarity establishment in plants, including the frequently used forward and reverse genetics screens as well as a novel chemical genetics approach that is expected to overcome the limitation of classical genetics methods.

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Schematic of polar domains in the plant epidermal and animal epithelialcells. Plant epidermal cells exhibit four polar domains, apical, basal,inner lateral and outer lateral, and are surrounded by cell walls.Animal epithelial cells exhibit apical and basolateral domains separatedby tight junctions.
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RSOB140017F1: Schematic of polar domains in the plant epidermal and animal epithelialcells. Plant epidermal cells exhibit four polar domains, apical, basal,inner lateral and outer lateral, and are surrounded by cell walls.Animal epithelial cells exhibit apical and basolateral domains separatedby tight junctions.

Mentions: Eukaryotic cells share common cellular components that are involved in cellpolarization, such as the endomembrane system, cytoskeleton, extracellularmatrix/cell wall and molecular regulators of polarity (such as Rab GTPases).Nevertheless, the independent evolution of multicellularity in plants and animalsresulted in the origin of specific executors and structures, such as cell walls inplants or tight junctions in animals, associated with the establishment andmaintenance of polarity. In the animal system, the most remarkable polaritydeterminants (partitioning defective (PAR) and the Scribble and Crumbs complexes)serve as components to multiple effector pathways, including cytoskeleton formation,cell–cell junctions and cell membrane and cortex organization, ensuringformation and maintenance of polar domains as a consequence [29–33]. Plants have established their own polarization manner based on theactivity of the Rho-like small G proteins, designated RAC/Rho of plants (ROP)GTPases [34], which are domainidentity proteins. ROP GTPases are master molecular switches controlling cellpolarization by regulating vesicle trafficking, interacting with cytoskeleton orworking as domain identity proteins. Additionally, PIN proteins are importantfactors that induce their own polarity: they are auxin transporters, not regulatoryproteins, and they need a polarized vesicular transport. Furthermore, the polardomains are differently organized in plants and animals (figure 1). In plant epidermal cells, four polardomains have been identified: the apical, basal, outer lateral and inner lateral,whereas in animal epithelial cells, only basolateral and apical domains can bedistinguished separated by the so-called tight junctions [35]. Figure 1.


Polar delivery in plants; commonalities and differences to animal epithelial cells.

Kania U, Fendrych M, Friml J - Open Biol (2014)

Schematic of polar domains in the plant epidermal and animal epithelialcells. Plant epidermal cells exhibit four polar domains, apical, basal,inner lateral and outer lateral, and are surrounded by cell walls.Animal epithelial cells exhibit apical and basolateral domains separatedby tight junctions.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4043115&req=5

RSOB140017F1: Schematic of polar domains in the plant epidermal and animal epithelialcells. Plant epidermal cells exhibit four polar domains, apical, basal,inner lateral and outer lateral, and are surrounded by cell walls.Animal epithelial cells exhibit apical and basolateral domains separatedby tight junctions.
Mentions: Eukaryotic cells share common cellular components that are involved in cellpolarization, such as the endomembrane system, cytoskeleton, extracellularmatrix/cell wall and molecular regulators of polarity (such as Rab GTPases).Nevertheless, the independent evolution of multicellularity in plants and animalsresulted in the origin of specific executors and structures, such as cell walls inplants or tight junctions in animals, associated with the establishment andmaintenance of polarity. In the animal system, the most remarkable polaritydeterminants (partitioning defective (PAR) and the Scribble and Crumbs complexes)serve as components to multiple effector pathways, including cytoskeleton formation,cell–cell junctions and cell membrane and cortex organization, ensuringformation and maintenance of polar domains as a consequence [29–33]. Plants have established their own polarization manner based on theactivity of the Rho-like small G proteins, designated RAC/Rho of plants (ROP)GTPases [34], which are domainidentity proteins. ROP GTPases are master molecular switches controlling cellpolarization by regulating vesicle trafficking, interacting with cytoskeleton orworking as domain identity proteins. Additionally, PIN proteins are importantfactors that induce their own polarity: they are auxin transporters, not regulatoryproteins, and they need a polarized vesicular transport. Furthermore, the polardomains are differently organized in plants and animals (figure 1). In plant epidermal cells, four polardomains have been identified: the apical, basal, outer lateral and inner lateral,whereas in animal epithelial cells, only basolateral and apical domains can bedistinguished separated by the so-called tight junctions [35]. Figure 1.

Bottom Line: Although plant and animal cells use a similar core mechanism to deliver proteins to the plasma membrane, their different lifestyle, body organization and specific cell structures resulted in the acquisition of regulatory mechanisms that vary in the two kingdoms.In particular, cell polarity regulators do not seem to be conserved, because genes encoding key components are absent in plant genomes.In animals, much information is provided from the study of polarity in epithelial cells that exhibit basolateral and luminal apical polarities, separated by tight junctions.

View Article: PubMed Central - PubMed

Affiliation: Institute of Science and Technology Austria (IST Austria), 3400 Klosterneuburg, Austria.

ABSTRACT
Although plant and animal cells use a similar core mechanism to deliver proteins to the plasma membrane, their different lifestyle, body organization and specific cell structures resulted in the acquisition of regulatory mechanisms that vary in the two kingdoms. In particular, cell polarity regulators do not seem to be conserved, because genes encoding key components are absent in plant genomes. In plants, the broad knowledge on polarity derives from the study of auxin transporters, the PIN-FORMED proteins, in the model plant Arabidopsis thaliana. In animals, much information is provided from the study of polarity in epithelial cells that exhibit basolateral and luminal apical polarities, separated by tight junctions. In this review, we summarize the similarities and differences of the polarization mechanisms between plants and animals and survey the main genetic approaches that have been used to characterize new genes involved in polarity establishment in plants, including the frequently used forward and reverse genetics screens as well as a novel chemical genetics approach that is expected to overcome the limitation of classical genetics methods.

Show MeSH