Microtubule-associated protein 1 subunit expression in primary cultures of rat brain

• Published in: Brain Research Bulletin 2000-12, Vol.53 (6), p.801-806
• Main Authors: Mei, Xun, Sweatt, Andrew J, Hammarback, James A
• Format: Article
• Language: English
• Subjects: Animals; Axon; Biochemistry and metabolism; Biological and medical sciences; Brain - cytology; Brain - embryology; Brain - metabolism; Cells, Cultured - cytology; Cells, Cultured - metabolism; Central nervous system; Cytoskeleton; Development; Fetus; Fluorescent Antibody Technique; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation, Developmental - physiology; Growth Cones - metabolism; Growth Cones - ultrastructure; Immunofluorescence; Microtubule-Associated Proteins - chemistry; Microtubule-Associated Proteins - genetics; Microtubule-Associated Proteins - metabolism; Neurite; Neurites - metabolism; Neurites - ultrastructure; Rats; Vertebrates: nervous system and sense organs
• ISSN: 0361-9230; 1873-2747
• DOI: 10.1016/S0361-9230(00)00416-0

Microtubule-associated protein 1A (MAP1A) and MAP1B are developmentally regulated proteins linked to axon formation. They each consist of a unique heavy chain and three common light chains. We used immunofluorescence microscopy to qualitatively assess the variability in MAP1 subunit expression between individual cells. The ratio of light chain 1 to MAP1 heavy chain varies greatly between cells with some cells expressing MAP1A heavy chain in the apparent absence of light chain 1. The results imply the existence of MAP1 molecules that differ in light chain composition. Transfection experiments indicate that the light chains differ in microtubule binding activity and subcellular targeting activity. This further suggests that the regulation of MAP1 light chain content can control MAP1 function.