MINT‐6603828: delta CaMK-II (uniprotkb:Q6PHZ2) binds (MI:0407) to Flightless-I (uniprotkb:Q9JJ28) by anti bait coimmunoprecipitation (MI:0006) MINT‐6603847: delta CaMK-II (uniprotkb:Q6PHZ2) phosphorylates (MI:0217) MAP2 (uniprotkb:P20357) by protein kinase assay (MI:0424) MINT‐6603768: beta CaMK-II (uniprotkb:P28652) physically interacts (MI:0218) with Flightless-I (uniprotkb:Q9JJ28) by anti bait coimmunoprecipitation (MI:0006) MINT‐6603759, MINT‐6603776, MINT‐6603786: delta CaMK-II (uniprotkb:Q6PHZ2) physically interacts (MI:0218) with Flightless-I (uniprotkb:Q9JJ28) by anti bait coimmunoprecipitation (MI:0006) MINT‐6603724: CaMK-II delta (uniprotkb:Q6PHZ2) physically interacts (MI:0218) with beta 5tubulin (uniprotkb:P99024), beta 2c tubulin (uniprotkb:P68372), alpha 1a tubulin (uniprotkb:P68369), b-Actin (uniprotkb:P60710), Tropomodulin-3 (uniprotkb:Q9JHJ0), Flightless-I (uniprotkb:Q9JJ28), FLAP1 (uniprotkb:Q3UZ39) and FLAP2 (uniprotkb:Q91WK0) by anti tag coimmunoprecipitation (MI:0007).

In neurons, the interaction of laminin with its receptor, beta 1 integrin, is accompanied by an increase in cytosolic Ca2+. Neuronal behavior is influenced by CaMK-II, the type II Ca2+/calmodulin-dependent protein kinase, which is enriched in axons of mouse embryonic neurons. In this study, we sought to determine whether CaMK-II is activated by laminin, and if so, how CaMK-II influences axonal growth and stability. Axons grew up to 200 mu m within 1 day of plating P19 embryoid bodies on laminin-1 (EHS laminin). Activated CaMK-II was found enriched along the axon and in the growth cone as detected using a phospho-Thr(287) specific CaMK-II antibody. beta 1 integrin was found in a similar pattern along the axon and in the growth cone. Direct inhibition of CaMK-II in 1-day-old neurons immediately froze growth cone dynamics, disorganized F-actin and ultimately led to axon retraction. Collapsed axonal remnants exhibited diminished phospho-CaMK-II levels. Treatment of 1-day neurons with a beta 1 integrin-blocking antibody (CD29) also reduced axon length and phospho-CaMK-II levels and, like CaMK-II inhibitors, decreased CaMK-II activation. Among several CaMK-II variants detected in these cultures, the S2-kDa delta variant preferentially associated with actin and beta(3) tubulin as determined by reciprocal immunoprecipitation. our findings indicate that persistent activation of delta CaMK-II by laminin stabilizes nascent embryonic axons through its influence on the actin cytoskeleton. (c) 2006 Elsevier B.V. All rights reserved.