Semaphorin3A signalling is mediated via sequential Cdk5 and GSK3β phosphorylation of CRMP2: implication of common phosphorylating mechanism underlying axon guidance and Alzheimer's disease

Abstract

Collapsin response mediating protein-2 (CRMP2) has been identified as an intracellular protein mediating Semaphorin3A (Sema3A), a repulsive guidance molecule. In this study, we demonstrate that cyclin-dependent kinase 5 (Cdk5) and glycogen synthase kinase 3β β β β (GSK3β β β β ) plays a critical role in Sema3A signalling. In In vitro kinase assay, Cdk5 phosphorylated CRMP2 at Ser522, while GSK3β β β β did not induce any phosphorylation of CRMP2. Phosphorylation by GSK3β β β β was exclusively observed in Cdk5-phosphorylated CRMP2, but barely in CRMP2T509A. These results indicate that Cdk5 primarily phosphorylates CRMP2 at Ser522 and GSK3β β β β secondarily phosphorylates at Thr509. The dual-phosphorylated CRMP2, but not non-phosphorylated or single-phosphorylated CRMP2, is recognized with the antibody 3F4, which is highly reactive with the neurofibrillary tangles of Alzheimer's disease. 3F4 recognized the CRMP2 in the wild-type but not cdk5 − − − − /− − − − mouse embryonic brain lysates. The phosphorylation of CRMP2 at Ser522 caused reduction of its affinity to tubulin. In dorsal root ganglion neurones, Sema3A stimulation enhanced the levels of the phosphorylated form of CRMP2 detected by 3F4. Over-expression of CRMP2 mutant substituting either Ser522 or Thr509 to Ala attenuates Sema3A-induced growth cone collapse response. These results suggest that the sequential phosphorylation of CRMP is an important process of Sema3A signalling and the same mechanism may have some relevance to the pathological aggregation of the microtubule-associated proteins.

Collapsin Response Mediator Protein 1 Mediates Reelin Signaling in Cortical Neuronal Migration

“…The expression pattern of another CRMP family member, crmp2, was almost similar to that of crmp1 (Wang and Strittmatter, 1996). Both CRMP1 and CRMP2 are involved in mediating Sema3A signaling (Uchida et al, 2005). These findings are consistent with a mild defect in neuronal migration in the crmp1 Ϫ/Ϫ cortex, rather than in the Reln rl/rl cerebral cortex.…”

“…CRMPs are now known to be composed of five homologous cytosolic proteins; all of the family proteins are phosphorylated and are highly expressed in developing and adult nervous systems (Wang and Strittmatter, 1996;Fukada et al, 2000;Inatome et al, 2000;Yuasa-Kawada et al, 2003). CRMPs also mediate other signaling, such as NT3, and are involved in many aspects of neuronal cell development by regulating cytoskeletal organization (Goshima et al, 1995Quach et al, 2004;Arimura and Kaibuchi, 2005;Uchida et al, 2005;Yoshimura et al, 2005). However, in vivo roles of CRMPs are mostly unknown.…”

Regulation of dendritic development by semaphorin 3A through novel intracellular remote signaling

“…CRMP2 binds the tubulin heterodimer and promotes microtubule assembly at the plus end, and the phosphorylation of CRMP2 at Ser522 reduces its affinity to tubulin. [43][44][45] The lowered affinity of phosphorylated CRMPs to tubulin may be responsible for Sema3A-induced axon repulsion or growth cone collapse. 36,45,46 As substrates, CRMPs also physically interact with the intracellular molecule interacting with CasL (MICAL), and transduce Sema3A signaling.…”

“…[43][44][45] The lowered affinity of phosphorylated CRMPs to tubulin may be responsible for Sema3A-induced axon repulsion or growth cone collapse. 36,45,46 As substrates, CRMPs also physically interact with the intracellular molecule interacting with CasL (MICAL), and transduce Sema3A signaling. 47,48 Another possible mechanism for Sema3A-induced cytoskeletal reorganization is the regulation of the function of 42 PlexinA GAP activity is regulated by FERM, RhoGEF and pleckstrin domain protein 2 (FARP2)-mediated Rac1 activation.…”

A hard road in psychiatric genetics: schizophrenia and DPYSL2

“…genome.jp/dbget-bin/www_bget?pathway+ hsa04360) is a key stage in the formation of the neuronal network. Several molecules, such as c-Fes, 2 CDK5 (cyclin-dependent kinase 5) 3 and ROCK2 (Rho-associated, coiled-coil containing protein kinase 2), 4 have been shown to phosphorylate DPYSL2 (denoted as CRMP2 in Figure 1), and DPYSL2 binds to tubulin heterodimers to promote microtubule assembly, which is important for axon outgrowth and branching. [5][6][7] Ephrin-A receptors/Ephexin/Rho A cascade is also an important regulator of cytoskeleton rearrangement (Figure 1).…”