Involvement of Ca 2+/calmodulin-dependent protein kinase II in neurite outgrowth induced by cAMP treatment and serum deprivation in a central nervous system cell line, CAD derived from rat brain

Abstract

A central nervous system (CNS) cell line, CAD, is known to differentiate in the absence of serum. This cell line was found to differentiate by the treatment of cAMP. Expression of Ca 2+/calmodulin-dependent protein kinase II (CaM kinase II) was induced to about 2-fold or more on day 1, and was continued at a high level for 5 days after the exposure to differentiating conditions. Neurite extension was stimulated from day 1 and continued for 5 days, suggesting that CaM kinase II activity is correlated with neurite outgrowth. Of the four distinct isoforms (α, β, γ, and δ) of the kinase, the δ isoform was the major isoform in CAD cells. The splicing pattern of this isoform in the differentiated cells differed from that in undifferentiated cells, suggesting that expression of CaM kinase II is regulated during neural differentiation.