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A role for sorting nexin 27 in AMPA receptor trafficking.

Loo LS, Tang N, Al-Haddawi M, Dawe GS, Hong W - Nat Commun (2014)

Bottom Line: Mechanistically, SNX27 interacts with K-ras GTPase via the RA domain; and following chemical LTP stimuli, K-ras is recruited to SNX27-enriched endosomes through a Ca(2+)/CaM-dependent mechanism, which in turn drives the synaptic delivery of homomeric GluA1 receptors.Impairment of SNX27 prevents LTP and associated trafficking of AMPARs.These results demonstrate a role for SNX27 in neuronal plasticity, provide a molecular explanation for the K-ras signal during LTP and identify SNX27 as the PDZ-containing molecular linker that couples the plasticity stimuli to the delivery of postsynaptic cargo.

View Article: PubMed Central - PubMed

Affiliation: 1] Institute of Molecular and Cell Biology, Singapore 138673, Singapore [2] Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 637553, Singapore.

ABSTRACT
Sorting nexin 27 (SNX27), a PDZ domain-containing endosomal protein, was recently shown to modulate glutamate receptor recycling in Down's syndrome. However, the precise molecular role of SNX27 in GluA1 trafficking is unclear. Here we report that SNX27 is enriched in dendrites and spines, along with recycling endosomes. Significantly, the mobilization of SNX27 along with recycling endosomes into spines was observed. Mechanistically, SNX27 interacts with K-ras GTPase via the RA domain; and following chemical LTP stimuli, K-ras is recruited to SNX27-enriched endosomes through a Ca(2+)/CaM-dependent mechanism, which in turn drives the synaptic delivery of homomeric GluA1 receptors. Impairment of SNX27 prevents LTP and associated trafficking of AMPARs. These results demonstrate a role for SNX27 in neuronal plasticity, provide a molecular explanation for the K-ras signal during LTP and identify SNX27 as the PDZ-containing molecular linker that couples the plasticity stimuli to the delivery of postsynaptic cargo.

No MeSH data available.


Related in: MedlinePlus

Loss of spine distribution in the truncated mutants.Cultured hippocampal neurons (17 div) transfected with GFP-tagged full-length SNX27 or SNX27 deletion mutants. mCherry-PSD95 was also expressed to identify spines. Fluorescence signal was quantified along the length (dashed line) of the image. For full-length SNX27, there is overlap of the red and green peaks indicating colocalization of the corresponding spots, whereas for the mutants, the green peaks are much lower than the red peak indicating minimal localization in the spines. Scale bar, 2 μm.
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f3: Loss of spine distribution in the truncated mutants.Cultured hippocampal neurons (17 div) transfected with GFP-tagged full-length SNX27 or SNX27 deletion mutants. mCherry-PSD95 was also expressed to identify spines. Fluorescence signal was quantified along the length (dashed line) of the image. For full-length SNX27, there is overlap of the red and green peaks indicating colocalization of the corresponding spots, whereas for the mutants, the green peaks are much lower than the red peak indicating minimal localization in the spines. Scale bar, 2 μm.

Mentions: SNX27 has three structural domains: the PDZ, PX and RA domains. To establish the role of each domain in spine distribution, we constructed three deletion mutants with each of the structural domains independently deleted: GFP-tagged SNX27ΔPDZ, SNX27ΔPX and SNX27ΔRA and verified their expression by transfecting cultured neurons (14 DIV) with the respective construct and examining their fluorescence signal (Supplementary Fig. 3). For the truncated constructs, expression was limited to the cell body and proximal dendrites; little to no expression was detected in the distal dendrites and spines (Supplementary Fig. 3). We further took hippocampal neurons (17 DIV), transfected them with the respective constructs and quantified the green and red fluorescence signal along the length (dashed line) of the image (Fig. 3). For full-length SNX27, there is overlap of the red and green peaks indicating colocalization of the corresponding spots, whereas for the mutants, the green peaks are much lower than the red peak indicating minimal distribution in the spines. Taken together, the result demonstrates the loss of spine distribution with all three mutants and suggests the collective importance of all three structural domains for spine distribution.


A role for sorting nexin 27 in AMPA receptor trafficking.

Loo LS, Tang N, Al-Haddawi M, Dawe GS, Hong W - Nat Commun (2014)

Loss of spine distribution in the truncated mutants.Cultured hippocampal neurons (17 div) transfected with GFP-tagged full-length SNX27 or SNX27 deletion mutants. mCherry-PSD95 was also expressed to identify spines. Fluorescence signal was quantified along the length (dashed line) of the image. For full-length SNX27, there is overlap of the red and green peaks indicating colocalization of the corresponding spots, whereas for the mutants, the green peaks are much lower than the red peak indicating minimal localization in the spines. Scale bar, 2 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3921469&req=5

f3: Loss of spine distribution in the truncated mutants.Cultured hippocampal neurons (17 div) transfected with GFP-tagged full-length SNX27 or SNX27 deletion mutants. mCherry-PSD95 was also expressed to identify spines. Fluorescence signal was quantified along the length (dashed line) of the image. For full-length SNX27, there is overlap of the red and green peaks indicating colocalization of the corresponding spots, whereas for the mutants, the green peaks are much lower than the red peak indicating minimal localization in the spines. Scale bar, 2 μm.
Mentions: SNX27 has three structural domains: the PDZ, PX and RA domains. To establish the role of each domain in spine distribution, we constructed three deletion mutants with each of the structural domains independently deleted: GFP-tagged SNX27ΔPDZ, SNX27ΔPX and SNX27ΔRA and verified their expression by transfecting cultured neurons (14 DIV) with the respective construct and examining their fluorescence signal (Supplementary Fig. 3). For the truncated constructs, expression was limited to the cell body and proximal dendrites; little to no expression was detected in the distal dendrites and spines (Supplementary Fig. 3). We further took hippocampal neurons (17 DIV), transfected them with the respective constructs and quantified the green and red fluorescence signal along the length (dashed line) of the image (Fig. 3). For full-length SNX27, there is overlap of the red and green peaks indicating colocalization of the corresponding spots, whereas for the mutants, the green peaks are much lower than the red peak indicating minimal distribution in the spines. Taken together, the result demonstrates the loss of spine distribution with all three mutants and suggests the collective importance of all three structural domains for spine distribution.

Bottom Line: Mechanistically, SNX27 interacts with K-ras GTPase via the RA domain; and following chemical LTP stimuli, K-ras is recruited to SNX27-enriched endosomes through a Ca(2+)/CaM-dependent mechanism, which in turn drives the synaptic delivery of homomeric GluA1 receptors.Impairment of SNX27 prevents LTP and associated trafficking of AMPARs.These results demonstrate a role for SNX27 in neuronal plasticity, provide a molecular explanation for the K-ras signal during LTP and identify SNX27 as the PDZ-containing molecular linker that couples the plasticity stimuli to the delivery of postsynaptic cargo.

View Article: PubMed Central - PubMed

Affiliation: 1] Institute of Molecular and Cell Biology, Singapore 138673, Singapore [2] Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 637553, Singapore.

ABSTRACT
Sorting nexin 27 (SNX27), a PDZ domain-containing endosomal protein, was recently shown to modulate glutamate receptor recycling in Down's syndrome. However, the precise molecular role of SNX27 in GluA1 trafficking is unclear. Here we report that SNX27 is enriched in dendrites and spines, along with recycling endosomes. Significantly, the mobilization of SNX27 along with recycling endosomes into spines was observed. Mechanistically, SNX27 interacts with K-ras GTPase via the RA domain; and following chemical LTP stimuli, K-ras is recruited to SNX27-enriched endosomes through a Ca(2+)/CaM-dependent mechanism, which in turn drives the synaptic delivery of homomeric GluA1 receptors. Impairment of SNX27 prevents LTP and associated trafficking of AMPARs. These results demonstrate a role for SNX27 in neuronal plasticity, provide a molecular explanation for the K-ras signal during LTP and identify SNX27 as the PDZ-containing molecular linker that couples the plasticity stimuli to the delivery of postsynaptic cargo.

No MeSH data available.


Related in: MedlinePlus