Chronological expression of microtubule-associated proteins (MAPs) in EC cell P19 after neuronal induction by retinoic acid.
Pluripotent murine embryonal carcinoma (EC) P19 cells are induced at a high rate into neural cells using retinoic acid and serum-free medium. EM observation revealed great increase of microtubules (MTs) after neuronal induction. To study the expression of microtubule-associated proteins (MAPs), immunoblotting and immunocytochemistry were performed with phosphorylated MAP1B (pMAP1B)-, MAP2-, and MAP1A-specific monoclonal antibodies. They did not stain undifferentiated cells. Early MAPs (pMAP1B and MAP2C) appeared 12 h after the neuronal induction, changing to late MAPs (MAP1A and MAP2A/B) at 3-5 days. These expression patterns are quite similar to those of neural cells in vivo. Anti-pMAP1B stained not only neurites but also the cell body and varicosities. But after extraction of the soluble component by permeabilization, pMAP1B was found in only MT-domains of the neurites at LM and EM levels, indicating that some part of pMAP1B is a structural component of neurite MTs and others exist in a soluble form. After culturing for more than 5 days, pMAP1B disappeared from the soma, but still remained in the distal ends of neurites. Here we showed that P19 is a good model system for studying the expression of MAPs on the continuous course of neuronal differentiation.
Tanaka
Y
Y
Department of Anatomy and Cell Biology, School of Medicine, University of Tokyo, Japan.
Kawahata
K
K
Nakata
T
T
Hirokawa
N
N
D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D054278:Embryonal Carcinoma Stem Cells; D007150:Immunohistochemistry; D051379:Mice; D016253:Microscopy, Immunoelectron; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism; D014411:Neoplastic Stem Cells / Q000166:cytology / Q000378:metabolism*; D016501:Neurites / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000378:metabolism; D010766:Phosphorylation; D013997:Time Factors; D014018:Tissue Distribution; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D008869:Microtubule-Associated Proteins; C085284:microtubule-associated protein 1B; D014212:Tretinoin