Extracellular Signals Induce Glycoprotein M6a Clustering of Lipid Rafts and Associated Signaling Molecules.
J Neurosci
; 37(15): 4046-4064, 2017 04 12.
Article
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| MEDLINE
| ID: mdl-28275160
ABSTRACT
Lipid raft domains, where sphingolipids and cholesterol are enriched, concentrate signaling molecules. To examine how signaling protein complexes are clustered in rafts, we focused on the functions of glycoprotein M6a (GPM6a), which is expressed at a high concentration in developing mouse neurons. Using imaging of lipid rafts, we found that GPM6a congregated in rafts in a GPM6a palmitoylation-dependent manner, thereby contributing to lipid raft clustering. In addition, we found that signaling proteins downstream of GPM6a, such as Rufy3, Rap2, and Tiam2/STEF, accumulated in lipid rafts in a GPM6a-dependent manner and were essential for laminin-dependent polarity during neurite formation in neuronal development. In utero RNAi targeting of GPM6a resulted in abnormally polarized neurons with multiple neurites. These results demonstrate that GPM6a induces the clustering of lipid rafts, which supports the raft aggregation of its associated downstream molecules for acceleration of neuronal polarity determination. Therefore, GPM6a acts as a signal transducer that responds to extracellular signals.SIGNIFICANCE STATEMENT Lipid raft domains, where sphingolipids and cholesterol are enriched, concentrate signaling molecules. We focused on glycoprotein M6a (GPM6a), which is expressed at a high concentration in developing neurons. Using imaging of lipid rafts, we found that GPM6a congregated in rafts in a palmitoylation-dependent manner, thereby contributing to lipid raft clustering. In addition, we found that signaling proteins downstream of GPM6a accumulated in lipid rafts in a GPM6a-dependent manner and were essential for laminin-dependent polarity during neurite formation. In utero RNAi targeting of GPM6a resulted in abnormally polarized neurons with multiple neurites. These results demonstrate that GPM6a induces the clustering of lipid rafts, which supports the raft aggregation of its associated downstream molecules for acceleration of polarity determination. Therefore, GPM6a acts as a signal transducer that responds to extracellular signals.
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1
Banco de datos:
MEDLINE
Asunto principal:
Glicoproteínas de Membrana
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Transducción de Señal
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Microdominios de Membrana
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Líquido Extracelular
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Proteínas del Tejido Nervioso
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
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Female
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Humans
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Male
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Pregnancy
Idioma:
En
Revista:
J Neurosci
Año:
2017
Tipo del documento:
Article