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.
Protein 4.1N was identified as a binding molecule for the C-terminal cytoplasmic tail of inositol 1,4,5-trisphosphate receptor type 1 (IP(3)R1) using a yeast two-hybrid system. 4.1N and IP(3)R1 associate in both subconfluent and confluent Madin-Darby canine kidney (MDCK) cells, a well studied tight polarized epithelial cell line. In subconfluent MDCK cells, 4.1N is distributed in the cytoplasm and the nucleus; IP(3)R1 is localized in the cytoplasm. In confluent MDCK cells, both 4.1N and IP(3)R1 are predominantly translocated to the basolateral membrane domain, whereas 4.1R, the prototypical homologue of 4.1N, is localized at the tight junctions (Mattagajasingh, S. N., Huang, S. C., Hartenstein, J. S., and Benz, E. J., Jr. (2000) J. Biol. Chem. 275, 30573-30585), and other endoplasmic reticulum marker proteins are still present in the cytoplasm. Moreover, the 4.1N-binding region of IP(3)R1 is necessary and sufficient for the localization of IP(3)R1 at the basolateral membrane domain. A fragment of the IP(3)R1-binding region of 4.1N blocks the localization of co-expressed IP(3)R1 at the basolateral membrane domain. These data indicate that 4.1N is required for IP(3)R1 translocation to the basolateral membrane domain in polarized MDCK cells.
Zhang
Songbai
S
Division of Molecular Neurobiology, The Institute of Medical Science, The University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Japan. sbzhang@ims.u-tokyo.ac.jp
Mizutani
Akihiro
A
Hisatsune
Chihiro
C
Higo
Takayasu
T
Bannai
Hiroko
H
Nakayama
Tomohiro
T
Hattori
Mitsuharu
M
Mikoshiba
Katsuhiko
K
D000818:Animals; D001483:Base Sequence; D001485:Basement Membrane / Q000378:metabolism; D015153:Blotting, Western; D001921:Brain / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism*; D002460:Cell Line; D003593:Cytoplasm / Q000378:metabolism; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D004285:Dogs; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D009479:Neuropeptides; D011233:Precipitin Tests; D011485:Protein Binding; D021381:Protein Transport; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*
D015220:Calcium Channels; D003598:Cytoskeletal Proteins; D017931:DNA Primers; D053496:Inositol 1,4,5-Trisphosphate Receptors; D008565:Membrane Proteins; D009479:Neuropeptides; D018160:Receptors, Cytoplasmic and Nuclear; C028841:erythrocyte membrane band 4.1 protein; C120557:erythrocyte membrane protein band 4.1-like 1