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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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Intracellular trafficking and cellular requirements for polarizationof PIN proteins. Auxin binding to its receptor ABP1 inhibitsclathrin-mediated endocytosis (CME) through ROP6/RIC4 signalling.PIN proteins require the DRP1 function for CME. They areinternalized to the TGN/EE and then follow the pathway to the REthat is regulated by BEN1 and VPS45/BEN2 ARF-GEFs. Recycling of PINproteins from the RE to the PM is regulated by a GNOM-dependentmechanism. Control of apical and basal PIN targeting depends on thephosphorylation status of PIN proteins. PIN proteins are directed tothe apical domain through phosphorylation by PID/WAG1/WAG2 kinases,whereas they are guided to the basal domain by dephosphorylation bymeans of PP2A/FyPP1/FyPP3 phosphatases. Basal targeting of PINcargoes is controlled by GNOM. BFA, brefeldin A.
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RSOB140017F2: Intracellular trafficking and cellular requirements for polarizationof PIN proteins. Auxin binding to its receptor ABP1 inhibitsclathrin-mediated endocytosis (CME) through ROP6/RIC4 signalling.PIN proteins require the DRP1 function for CME. They areinternalized to the TGN/EE and then follow the pathway to the REthat is regulated by BEN1 and VPS45/BEN2 ARF-GEFs. Recycling of PINproteins from the RE to the PM is regulated by a GNOM-dependentmechanism. Control of apical and basal PIN targeting depends on thephosphorylation status of PIN proteins. PIN proteins are directed tothe apical domain through phosphorylation by PID/WAG1/WAG2 kinases,whereas they are guided to the basal domain by dephosphorylation bymeans of PP2A/FyPP1/FyPP3 phosphatases. Basal targeting of PINcargoes is controlled by GNOM. BFA, brefeldin A.

Mentions: Besides the involvement of polar secretion in the cellular polarization,establishment and maintenance of the distinct polar domain is also regulated, inboth plants and animals, by the constant polar recycling of the PM proteins. Inepithelial cells, internalized proteins from the apical and basolateral domainslocalize to the apical and basolateral early endosomes (EEs), respectively, fromwhere they can be recycled back to the PM, or targeted to the common recyclingendosome that plays multiple roles in the protein-sorting pathway where commontrafficking pathways intersect, such as recycling, secretion and transcytosis.Additionally, an apical recycling route encompasses the apical recyclingendosome that is involved in basal-to-apical transcytosis and transport of newlysynthesized proteins [49]. Inplants, PIN proteins are internalized from the PM to the TGN/EE compartments andcan further follow either the recycling route to the PM via hypotheticalcompartments, the REs (figure 2),or the degradation route to the vacuole via prevacuolar compartments thatcorrespond to late endosomes in plants [23,50]. FigureĀ 2.


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

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

Intracellular trafficking and cellular requirements for polarizationof PIN proteins. Auxin binding to its receptor ABP1 inhibitsclathrin-mediated endocytosis (CME) through ROP6/RIC4 signalling.PIN proteins require the DRP1 function for CME. They areinternalized to the TGN/EE and then follow the pathway to the REthat is regulated by BEN1 and VPS45/BEN2 ARF-GEFs. Recycling of PINproteins from the RE to the PM is regulated by a GNOM-dependentmechanism. Control of apical and basal PIN targeting depends on thephosphorylation status of PIN proteins. PIN proteins are directed tothe apical domain through phosphorylation by PID/WAG1/WAG2 kinases,whereas they are guided to the basal domain by dephosphorylation bymeans of PP2A/FyPP1/FyPP3 phosphatases. Basal targeting of PINcargoes is controlled by GNOM. BFA, brefeldin A.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

RSOB140017F2: Intracellular trafficking and cellular requirements for polarizationof PIN proteins. Auxin binding to its receptor ABP1 inhibitsclathrin-mediated endocytosis (CME) through ROP6/RIC4 signalling.PIN proteins require the DRP1 function for CME. They areinternalized to the TGN/EE and then follow the pathway to the REthat is regulated by BEN1 and VPS45/BEN2 ARF-GEFs. Recycling of PINproteins from the RE to the PM is regulated by a GNOM-dependentmechanism. Control of apical and basal PIN targeting depends on thephosphorylation status of PIN proteins. PIN proteins are directed tothe apical domain through phosphorylation by PID/WAG1/WAG2 kinases,whereas they are guided to the basal domain by dephosphorylation bymeans of PP2A/FyPP1/FyPP3 phosphatases. Basal targeting of PINcargoes is controlled by GNOM. BFA, brefeldin A.
Mentions: Besides the involvement of polar secretion in the cellular polarization,establishment and maintenance of the distinct polar domain is also regulated, inboth plants and animals, by the constant polar recycling of the PM proteins. Inepithelial cells, internalized proteins from the apical and basolateral domainslocalize to the apical and basolateral early endosomes (EEs), respectively, fromwhere they can be recycled back to the PM, or targeted to the common recyclingendosome that plays multiple roles in the protein-sorting pathway where commontrafficking pathways intersect, such as recycling, secretion and transcytosis.Additionally, an apical recycling route encompasses the apical recyclingendosome that is involved in basal-to-apical transcytosis and transport of newlysynthesized proteins [49]. Inplants, PIN proteins are internalized from the PM to the TGN/EE compartments andcan further follow either the recycling route to the PM via hypotheticalcompartments, the REs (figure 2),or the degradation route to the vacuole via prevacuolar compartments thatcorrespond to late endosomes in plants [23,50]. FigureĀ 2.

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