Evidence for Expression of Some Microtubule-Associated Protein 1B in Neurons as a Plasma Membrane Glycoprotein
| Autor: | Sandra L. Tanner, Howard Jaffe, Richard H. Quarles, Rachelle Franzen |
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| Rok vydání: | 2002 |
| Předmět: |
Molecular Sequence Data
Biology Biochemistry Rats Sprague-Dawley Cellular and Molecular Neuroscience Fetus Dorsal root ganglion Ganglia Spinal Microsomes medicine Animals Trypsin Amino Acid Sequence Cytoskeleton Cells Cultured Cerebral Cortex Neurons Vesicle Cell Membrane Brain Axons Peptide Fragments Axolemma Rats Cell biology Membrane glycoproteins medicine.anatomical_structure nervous system Membrane protein Synaptophysin biology.protein Neuron Microtubule-Associated Proteins |
| Zdroj: | Journal of Neurochemistry. 75:553-562 |
| ISSN: | 0022-3042 |
| Popis: | Microtubule-associated protein (MAP) 1B is a high-molecular-weight cytoskeletal protein that is abundant in developing neuronal processes and appears to be necessary for axonal growth. Various biochemical and immunocytochemical results are reported, indicating that a significant fraction of MAP1B is expressed as an integral membrane glycoprotein in vesicles and the plasma membrane of neurons. MAP1B is present in microsomal fractions isolated from developing rat brain and fractionates across a sucrose gradient in a manner similar to synaptophysin, a well-known vesicular and plasma membrane protein. MAP1B is also in axolemma-enriched fractions (AEFs) isolated from myelinated axons of rat brain. MAP1B in AEFs and membrane fractions from cultured dorsal root ganglion neurons (DRGNs) remains membrane-associated following high-salt washes and contains sialic acid. Furthermore, MAP1B in intact DRGNs is readily degraded by extracellular trypsin and is labeled by the cell surface probe sulfosuccinimidobiotin. Immunocytochemical examination of DRGNs shows that MAP1B is concentrated in vesicle-rich varicosities along the length of axons. Myelinated peripheral nerves immunostained for MAP1B show an enrichment at the axonal plasma membrane. These observations demonstrate that some of the MAP1B in developing neurons is an integral plasma membrane glycoprotein. |
| Databáze: | OpenAIRE |
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