Role of phosphorylated MAPlB in neuritogenesis.
The distribution of microtubule-associated protein lB (MAPlB) phosphorylated by either proline-directed protein kinase (PDPK) or casein kinase II (CK II) in neuroblastoma cells and hippocampal neurons has been studied by immunofluorescence using specific antibodies to distinct phosphorylation-sensitive epitopes. A proximo-distal gradient of increasing PDPK-catalyzed phosphorylation of MAPlB is superimposed on a proximo distal gradient of decreasing CK II-catalyzed MAPlB phosphorylation within growing axon-like neurites. Additionally, CK II-phosphorylated MAPlB is present in cell bodies and dendrites where no PDPK-phosphorylated MAPlB is observed. These results suggest distinct roles for both types of modifications of MAPlB in developing neurons.
Avila
J
J
Centro de Biologia Molecular Severo Ochoa (CSIC-UAM), Universidad Autonoma de Madrid, Spain.
Ulloa
L
L
Diez-Guerra
J
J
Diaz-Nido
J
J
D000818:Animals; D047390:Casein Kinase II; D002454:Cell Differentiation; D002478:Cells, Cultured; D000939:Epitopes / Q000032:analysis; D006624:Hippocampus / Q000166:cytology; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000378:metabolism*; D016501:Neurites / Q000378:metabolism* / Q000648:ultrastructure; D009447:Neuroblastoma; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D010766:Phosphorylation; D038461:Proline-Directed Protein Kinases; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D051381:Rats; D014407:Tumor Cells, Cultured
D000939:Epitopes; D008869:Microtubule-Associated Proteins; C085284:microtubule-associated protein 1B; D038461:Proline-Directed Protein Kinases; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases