Axonal localization of delta Ca2+/calmodulin-dependent protein kinase II in developing P19 neurons.
Ca(2+)/calmodulin-dependent protein kinase, type II (CaMK-II) is an enzyme encoded by four genes (alpha, beta, gamma and delta) and traditionally associated with synaptic function in the adult central nervous system, but also believed to play a role during neuronal development. P19 mouse embryonic cells are a model system for neurogenesis and primarily express isozymes of delta CaMK-II. It is not yet known whether or where delta CaMK-II is expressed in P19 neurons. Using an antibody specific for the delta CaMK-II C-terminal tail, we detected a 20-fold increase in levels of delta CaMK-II along axons after 8 days of development. This coincides with increased mRNA and protein levels of delta(C) CaMK-II, which contains the alternative tail. This follows the initial stages of neurite outgrowth and beta(3) tubulin expression, which occur after 4 days. delta CaMK-II co-localizes with the axonal protein GAP-43, but not the dendritic microtubule-associated protein MAP-2, a known substrate of alpha CaMK-II. Like delta CaMK-II, GAP-43 shows increased expression after 8 days. These findings demonstrate developmental regulation of the alternative C-terminal delta CaMK-II exon and implicate endogenous delta CaMK-II in axonal development in embryonic cells.
Faison
M Omar
MO
Department of Biology, Virginia Commonwealth University, 1000 West Cary Street, Richmond, VA 23284-2012, USA.
Perozzi
Ed F
EF
Caran
Nicole
N
Stewart
Jennifer K
JK
Tombes
Robert M
RM
D000818:Animals; D001369:Axons / Q000201:enzymology* / Q000378:metabolism; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D018929:Cell Culture Techniques; D002460:Cell Line; D019922:GAP-43 Protein / Q000378:metabolism; D006624:Hippocampus / Q000254:growth & development* / Q000378:metabolism; D015151:Immunoblotting; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism; D051379:Mice; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014404:Tubulin / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
D019922:GAP-43 Protein; D007527:Isoenzymes; D008869:Microtubule-Associated Proteins; D012333:RNA, Messenger; D014404:Tubulin; C462941:beta3 tubulin, mouse; D014446:Tyrosine 3-Monooxygenase; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases