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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

Ras-binding properties of SNX27.(a) Upper panel: selective interaction of endogenous K-ras with SNX27 in hippocampal lysate. Lower panel: immunoprecipitation of HEK293 cells expressing HA-K-ras and Myc-SNX27 full-length or SNX27 lacking RA domain (Myc-SNX27ΔRA). (b) Localization of SNX27 and K-ras with and without glycine treatment (200 μm, 5 min). The graph represents the mean of five independent experiments with 10 images each. (n=5, ** indicates P<0.05, unpaired t-test, error bars=s.e.m.). Scale bar, 2 μm. (c) Time dependence of K-ras binding to calmodulin following Gly, Gly/APV and Gly/EGTA stimulation (upper). Quantitative analysis of time course of K-ras binding to CaM following Gly (▪), Gly/APV (□) and Gly/EGTA (Δ) stimulation (lower). n=3. All error bars represent s.e.m.
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f7: Ras-binding properties of SNX27.(a) Upper panel: selective interaction of endogenous K-ras with SNX27 in hippocampal lysate. Lower panel: immunoprecipitation of HEK293 cells expressing HA-K-ras and Myc-SNX27 full-length or SNX27 lacking RA domain (Myc-SNX27ΔRA). (b) Localization of SNX27 and K-ras with and without glycine treatment (200 μm, 5 min). The graph represents the mean of five independent experiments with 10 images each. (n=5, ** indicates P<0.05, unpaired t-test, error bars=s.e.m.). Scale bar, 2 μm. (c) Time dependence of K-ras binding to calmodulin following Gly, Gly/APV and Gly/EGTA stimulation (upper). Quantitative analysis of time course of K-ras binding to CaM following Gly (▪), Gly/APV (□) and Gly/EGTA (Δ) stimulation (lower). n=3. All error bars represent s.e.m.

Mentions: Since activity causes redistribution of K-ras from the plasma membrane to endosomes7 (Supplementary Fig. 5a), we hypothesized that SNX27 is likely the endosome-docking molecule that decodes the plasticity signal from K-ras and drives GluA1 receptors into spines. To determine the K-ras-binding properties of SNX27, coimmunoprecipitation with anti-SNX27 was performed. K-ras (but not H-ras or N-ras) selectively interacts with SNX27 on endogenous hippocampal lysate (Fig. 7a). To validate this interaction, we expressed HA-K-ras and either myc-SNX27 or myc-SNX27-lacking K-ras-binding (RA) domain in HEK cells and immunoprecipitated with myc-antibody. As expected, full-length SNX27 (Fig. 7a, lower panel; lane 3) but not the truncated SNX27 (lane 4) interacted with K-ras, indicating that the SNX27 RA domain is required for the interaction with K-ras.


A role for sorting nexin 27 in AMPA receptor trafficking.

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

Ras-binding properties of SNX27.(a) Upper panel: selective interaction of endogenous K-ras with SNX27 in hippocampal lysate. Lower panel: immunoprecipitation of HEK293 cells expressing HA-K-ras and Myc-SNX27 full-length or SNX27 lacking RA domain (Myc-SNX27ΔRA). (b) Localization of SNX27 and K-ras with and without glycine treatment (200 μm, 5 min). The graph represents the mean of five independent experiments with 10 images each. (n=5, ** indicates P<0.05, unpaired t-test, error bars=s.e.m.). Scale bar, 2 μm. (c) Time dependence of K-ras binding to calmodulin following Gly, Gly/APV and Gly/EGTA stimulation (upper). Quantitative analysis of time course of K-ras binding to CaM following Gly (▪), Gly/APV (□) and Gly/EGTA (Δ) stimulation (lower). n=3. All error bars represent s.e.m.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f7: Ras-binding properties of SNX27.(a) Upper panel: selective interaction of endogenous K-ras with SNX27 in hippocampal lysate. Lower panel: immunoprecipitation of HEK293 cells expressing HA-K-ras and Myc-SNX27 full-length or SNX27 lacking RA domain (Myc-SNX27ΔRA). (b) Localization of SNX27 and K-ras with and without glycine treatment (200 μm, 5 min). The graph represents the mean of five independent experiments with 10 images each. (n=5, ** indicates P<0.05, unpaired t-test, error bars=s.e.m.). Scale bar, 2 μm. (c) Time dependence of K-ras binding to calmodulin following Gly, Gly/APV and Gly/EGTA stimulation (upper). Quantitative analysis of time course of K-ras binding to CaM following Gly (▪), Gly/APV (□) and Gly/EGTA (Δ) stimulation (lower). n=3. All error bars represent s.e.m.
Mentions: Since activity causes redistribution of K-ras from the plasma membrane to endosomes7 (Supplementary Fig. 5a), we hypothesized that SNX27 is likely the endosome-docking molecule that decodes the plasticity signal from K-ras and drives GluA1 receptors into spines. To determine the K-ras-binding properties of SNX27, coimmunoprecipitation with anti-SNX27 was performed. K-ras (but not H-ras or N-ras) selectively interacts with SNX27 on endogenous hippocampal lysate (Fig. 7a). To validate this interaction, we expressed HA-K-ras and either myc-SNX27 or myc-SNX27-lacking K-ras-binding (RA) domain in HEK cells and immunoprecipitated with myc-antibody. As expected, full-length SNX27 (Fig. 7a, lower panel; lane 3) but not the truncated SNX27 (lane 4) interacted with K-ras, indicating that the SNX27 RA domain is required for the interaction with K-ras.

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