BAALC 1-6-8 protein is targeted to postsynaptic lipid rafts by its N-terminal myristoylation and palmitoylation, and interacts with alpha, but not beta, subunit of Ca/calmodulin-dependent protein kinase II.
We cloned a rat BAALC 1-6-8 isoform cDNA (GenBank Accession No. AB073318) that encoded a 22-kDa protein, and identified endogenous BAALC 1-6-8 protein in the brain. The gene was expressed widely in the frontal part of the brain, and the protein was localized to the synaptic sites and was increased in parallel with synaptogenesis. The protein interacted with the alpha, but not beta, subunit of Ca(2+)/calmodulin-dependent protein kinase II (CaMKIIalpha). The interaction occurred between the N-terminal 35-amino-acid region of BAALC 1-6-8 protein and the C-terminal end of the regulatory domain of CaMKIIalpha, which contains alpha isoform-specific sequence. Thus, the interaction may be CaMKIIalpha-specific. We also found that BAALC 1-6-8 protein, as well as CaMKIIalpha, was localized to lipid rafts and that both myristoylation and palmitoylation of BAALC 1-6-8 N-terminal portion were required for targeting of the protein into lipid rafts. These findings suggest that BAALC 1-6-8 protein play a synaptic role at the postsynaptic lipid raft possibly through interaction with CaMKIIalpha.
Wang
Xin
X
Department of Neuroplasticity, Institute on Aging and Adaptation, Shinshu University Graduate School of Medicine, 3-1-1 Asahi, Matsumoto 390-8621, Japan.
Tian
Qing-Bao
QB
Okano
Akira
A
Sakagami
Hiroyuki
H
Moon
Il Soo
IS
Kondo
Hisatake
H
Endo
Shogo
S
Suzuki
Tatsuo
T
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D019556:COS Cells; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002522:Chlorocebus aethiops; D047468:Immunoprecipitation; D017403:In Situ Hybridization; D021962:Membrane Microdomains / Q000378:metabolism*; D008969:Molecular Sequence Data; D009227:Myristic Acids / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D010169:Palmitic Acids / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D021122:Protein Subunits / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013569:Synapses / Q000378:metabolism*
C486704:Baalc protein, rat; D009227:Myristic Acids; D009363:Neoplasm Proteins; D010169:Palmitic Acids; D020033:Protein Isoforms; D021122:Protein Subunits; D012333:RNA, Messenger; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases