Reduced expression of kinase-associated phosphatase in cortical dendrites of MAP2-deficient mice.
We previously demonstrated that cAMP-dependent protein kinase was reduced in the dendrites of MAP2-deficient mice. In this study, we compared the expression of various protein phosphatases (PPs) between wild-type and map2(-/-) dendrites. Kinase-associated phosphatase (KAP) was the only PP which showed difference between the two phenotypes: (1) the expression of KAP was reduced in map2(-/-) cortical dendrites, and (2) the amount of KAP bound to microtubules was reduced in map2(-/-) brains. We also demonstrated in cultured neuroblastoma cells that KAP is not only expressed in dividing cells, but also in the neurites of differentiated cells. Our findings propose that KAP, which has been reported to function in cell-cycle control, has an as yet uncovered role in regulating dendritic functions. We also propose MAP2-deficient mice as an ideal system for identifying protein phosphatases essential for dendritic functions.
Iriuchijima
Nobuhisa
N
Laboratory of Molecular Traffic, Department of Cell Biology, Institute for Molecular and Cellular Regulation, Gunma University, Maebashi, Gunma 371-8512, Japan.
Sato-Harada
Reiko
R
Takano
Mutsumi
M
Fujio
Katsunori
K
Sato
Takashi
T
Goto
Fumio
F
Harada
Akihiro
A
D000818:Animals; D002540:Cerebral Cortex / Q000201:enzymology*; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D003712:Dendrites / Q000201:enzymology*; D015536:Down-Regulation / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D008869:Microtubule-Associated Proteins / Q000172:deficiency* / Q000235:genetics; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases; D014018:Tissue Distribution
D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D008869:Microtubule-Associated Proteins; C079240:Mtap2 protein, mouse; D010749:Phosphoprotein Phosphatases; C508901:Cdkn3 protein, mouse; D017027:Protein Tyrosine Phosphatases