4.1N binding regions of inositol 1,4,5-trisphosphate receptor type 1.
Zhang et al. and Maximov et al. [S. Zhang, A. Mizutani, C. Hisatsune, T. Higo, H. Bannai, T. Nakayama, M. Hattori, and K. Mikoshiba, Protein 4.1N is required for translocation of inositol 1,4,5-trisphosphate receptor type 1 to the basolateral membrane domain in polarized Madin-Darby canine kidney cells, J. Biol. Chem. 278 (2003) 4048-4056; A. Maximov, T. S. Tang, and I. Bezprozvanny, Association of the type 1 inositol (1,4,5)-trisphosphate receptor with 4.1N protein in neurons, Mol. Cell. Neurosci. 22 (2003) 271-283.] reported that 4.1N is a binding partner of inositol 1,4,5-trisphosphate receptor type 1 (IP(3)R1), however the binding site of IP(3)R1 differed: the former determined the C-terminal 14 amino acids of the cytoplasmic tail (CTT14aa) as the binding site, while the latter assigned another segment, cytoplasmic tail middle 1 (CTM1). To solve this discrepancy, we performed immunoprecipitation and found that both the segments had binding activity to 4.1N. Both segments also interfered the 4.1N-regulated IP(3)R1 diffusion in neuronal dendrites. However, IP(3)R1 lacking the CTT14aa (IP(3)R1-DeltaCTT14aa) does not bind to 4.1N [S. Zhang, A. Mizutani, C. Hisatsune, T. Higo, H. Bannai, T. Nakayama, M. Hattori, and K. Mikoshiba, Protein 4.1N is required for translocation of inositol 1,4,5-trisphosphate receptor type 1 to the basolateral membrane domain in polarized Madin-Darby canine kidney cells, J. Biol. Chem. 278 (2003) 4048-4056.] and its diffusion constant is larger than that of IP(3)R1 full-length in neuronal dendrites [K. Fukatsu, H. Bannai, S. Zhang, H. Nakamura, T. Inoue, and K. Mikoshiba, Lateral diffusion of inositol 1,4,5-trisphosphate receptor type 1 is regulated by actin filaments and 4.1N in neuronal dendrites, J. Biol. Chem. 279 (2004) 48976-48982.]. We conclude that both the CTT14aa and CTM1 sequences can bind to 4.1N in peptide fragment forms. However, we propose that the responsible binding site for 4.1N binding in full-length tetramer form of IP(3)R1 is CTT14aa.
Division of Molecular Neurobiology, The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan.
Kazumi
K
Fukatsu
Hiroko
H
Bannai
Takafumi
T
Inoue
Katsuhiko
K
Mikoshiba
D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D015220:Calcium Channels / Q000378:metabolism*; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D017930:Genes, Reporter; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008562:Membrane Glycoproteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D009479:Neuropeptides / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D051381:Rats; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*
D015220:Calcium Channels; D003598:Cytoskeletal Proteins; D053496:Inositol 1,4,5-Trisphosphate Receptors; C488910:Itpr1 protein, rat; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D009479:Neuropeptides; D018160:Receptors, Cytoplasmic and Nuclear; C120557:erythrocyte membrane protein band 4.1-like 1; D015544:Inositol 1,4,5-Trisphosphate