Functional differences between two DCLK splice variants.
Recently, we have cloned two splice variants of the doublecortin-like kinase (DCLK) gene, called DCLK-short-A and -B, both of which encode calcium/calmodulin-dependent protein kinase (CaMK)-like proteins with different C-terminal ends. Using in situ hybridization, we have found that both are highly expressed in limbic structures of the brain and that their expression differs in a number of brain areas. DCLK-short-A is relatively more strongly expressed than DCLK-short-B in the subependymal zone. The DCLK-short-B variant shows stronger expression in the cortex, the ventromedial and dorsomedial hypothalamic nuclei, the arcuate nucleus, the zona incerta and the subincertal nucleus. Also, within the hippocampus, the relative distribution of these two splice variants differs. DCLK-short-B expression compared to DCLK-short-A is highest in the CA1 area. The expression of the A variant is highest in the CA3/CA4 area. Additionally, DCLK-short-B is expressed at a higher level than DCLK-short-A in the substantia nigra and the mammillary nucleus. Both DCLK-short-A and -B were located in the cytoplasm, however DCLK-short-B was also found specifically in growth cone like structures and near the nucleus. Both DCLK-short proteins phosphorylate autocamtide and syntide, two highly specific CaMK substrates. Finally, removal of the C-terminal end of DCLK-short leads to a 10-fold increase of kinase activity, indicating that the different C-termini represent auto-inhibitory domains. Our results indicate that DCLK-short-A and -B control different neuronal processes that overlap with those controlled by CaMKs.
Engels
Bart M
BM
Leiden/Amsterdam Center for Drug Research, Division of Medical Pharmacology, University of Leiden, PO Box 9503, 2300 RA, Leiden, The Netherlands
Schouten
Theo G
TG
van Dullemen
Joost
J
Gosens
Ilse
I
Vreugdenhil
Erno
E
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western / Q000379:methods; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism; D019556:COS Cells; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000145:classification / Q000235:genetics / Q000502:physiology*; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular / Q000379:methods; D004252:DNA Mutational Analysis / Q000379:methods; D000089662:Doublecortin Protein; D000089742:Doublecortin-Like Kinases; D015870:Gene Expression; D014644:Genetic Variation; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000145:classification / Q000235:genetics / Q000502:physiology*; D009447:Neuroblastoma; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism; D011233:Precipitin Tests / Q000379:methods; D017346:Protein Serine-Threonine Kinases; D011506:Proteins / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D014162:Transfection / Q000379:methods
C000714848:Dcx protein, rat; D000089662:Doublecortin Protein; D009419:Nerve Tissue Proteins; D011506:Proteins; D010770:Phosphotransferases; D000089742:Doublecortin-Like Kinases; C485526:Dclk1 protein, rat; D017346:Protein Serine-Threonine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases