Dataset Information

PAT1 inversely regulates the surface Amyloid Precursor Protein level in mouse primary neurons.

ABSTRACT: The amyloid precursor protein (APP) is a key molecule in Alzheimer disease. Its localization at the cell surface can trigger downstream signaling and APP cleavages. APP trafficking to the cell surface in neurons is not clearly understood and may be related to the interactions with its partners. In this respect, by having homologies with kinesin light chain domains and because of its capacity to bind APP, PAT1 represents a good candidate.We observed that PAT1 binds poorly APP at the cell surface of primary cortical neurons contrary to cytoplasmic APP. Using down and up-regulation of PAT1, we observed respectively an increase and decrease of APP at the cell surface. The increase of APP at the cell surface induced by low levels of PAT1 did not trigger cell death signaling.These data suggest that PAT1 slows down APP trafficking to the cell surface in primary cortical neurons. Our results contribute to the elucidation of mechanisms involved in APP trafficking in Alzheimer disease.

SUBMITTER: Dilsizoglu Senol A

PROVIDER: S-EPMC4355975 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

PAT1 inversely regulates the surface Amyloid Precursor Protein level in mouse primary neurons.

Dilsizoglu Senol Aysegul A Tagliafierro Lidia L Huguet Léa L Gorisse-Hussonnois Lucie L Chasseigneaux Stéphanie S Allinquant Bernadette B

BMC neuroscience 20150307

<h4>Background</h4>The amyloid precursor protein (APP) is a key molecule in Alzheimer disease. Its localization at the cell surface can trigger downstream signaling and APP cleavages. APP trafficking to the cell surface in neurons is not clearly understood and may be related to the interactions with its partners. In this respect, by having homologies with kinesin light chain domains and because of its capacity to bind APP, PAT1 represents a good candidate.<h4>Results</h4>We observed that PAT1 bi ...[more]

PMID: 25880931

Similar Datasets

Project description:Neurodegeneration associated with amyloid ? (A?) peptide accumulation, synaptic loss, and memory impairment are pathophysiological features of Alzheimer's disease (AD). Numerous microRNAs regulate amyloid precursor protein (APP) expression and metabolism. We previously reported that miR-101 is a negative regulator of APP expression in cultured hippocampal neurons. In this study, a search for predicted APP metabolism-associated miR-101 targets led to the identification of a conserved miR-101 binding site within the 3' untranslated region (UTR) of the mRNA encoding Ran-binding protein 9 (RanBP9). RanBP9 increases APP processing by ?-amyloid converting enzyme 1 (BACE1), secretion of soluble APP? (sAPP?), and generation of A?. MiR-101 significantly reduced reporter gene expression when co-transfected with a RanBP9 3'-UTR reporter construct, while site-directed mutagenesis of the predicted miR-101 target site eliminated the reporter response. To investigate the effect of stable inhibition of miR-101 both in vitro and in vivo, a microRNA sponge was developed to bind miR-101 and derepress its targets. Four tandem bulged miR-101 responsive elements (REs), located downstream of the enhanced green fluorescence protein (EGFP) open reading frame and driven by the synapsin promoter, were placed in a lentiviral vector to create the pLSyn-miR-101 sponge. Delivery of the sponge to primary hippocampal neurons significantly increased both APP and RanBP9 expression, as well as sAPP? levels in the conditioned medium. Importantly, silencing of endogenous RanBP9 reduced sAPP? levels in miR-101 sponge-containing hippocampal cultures, indicating that miR-101 inhibition may increase amyloidogenic processing of APP by RanBP9. Lastly, the impact of miR-101 on its targets was demonstrated in vivo by intrahippocampal injection of the pLSyn-miR-101 sponge into C57BL6 mice. This study thus provides the basis for studying the consequences of long-term miR-101 inhibition on the pathology of AD.

Project description:Amyloid precursor protein (APP) was originally identified as the source of ?-amyloid peptides that accumulate in Alzheimer's disease (AD), but it also has been implicated in the control of multiple aspects of neuronal motility. APP belongs to an evolutionarily conserved family of transmembrane proteins that can interact with a variety of adapter and signaling molecules. Recently, we showed that both APP and its insect ortholog [APPL (APP-Like)] directly bind the heterotrimeric G-protein Go?, supporting the model that APP can function as an unconventional Go?-coupled receptor. We also adapted a well characterized assay of neuronal migration in the hawkmoth, Manduca sexta, to show that APPL-Go? signaling restricts ectopic growth within the developing nervous system, analogous to the role postulated for APP family proteins in controlling migration within the mammalian cortex. Using this assay, we have now identified Manduca Contactin (MsContactin) as an endogenous ligand for APPL, consistent with previous work showing that Contactins interact with APP family proteins in other systems. Using antisense-based knockdown protocols and fusion proteins targeting both proteins, we have shown that MsContactin is selectively expressed by glial cells that ensheath the migratory neurons (expressing APPL), and that MsContactin-APPL interactions normally prevent inappropriate migration and outgrowth. These results provide new evidence that Contactins can function as authentic ligands for APP family proteins that regulate APP-dependent responses in the developing nervous system. They also support the model that misregulated Contactin-APP interactions might provoke aberrant activation of Go? and its effectors, thereby contributing to the neurodegenerative sequelae that typify AD.Members of the amyloid precursor protein (APP) family participate in many aspects of neuronal development, but the ligands that normally activate APP signaling have remained controversial. This research provides new evidence that members of the Contactin family function as authentic ligands for APP and its orthologs, and that this evolutionarily conserved class of membrane-attached proteins regulates key aspects of APP-dependent migration and outgrowth in the embryonic nervous system. By defining the normal role of Contactin-APP signaling during development, these studies also provide the framework for investigating how the misregulation of Contactin-APP interactions might contribute to neuronal dysfunction in the context of both normal aging and neurodegenerative conditions, including Alzheimer's disease.

Dataset Information

PAT1 inversely regulates the surface Amyloid Precursor Protein level in mouse primary neurons.

Publications

PAT1 inversely regulates the surface Amyloid Precursor Protein level in mouse primary neurons.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets