Molecular cloning and functional analysis of a novel Cx43 partner protein CIP150.
We identified and cloned a novel gene encoding a partner protein, CIP150, of connexin 43 (Cx43). CIP150 associates with Cx43 through its carboxyl terminal domain. Conversely, a region consisting of 16 amino acids in the juxtamembrane region (amino acids 227-242) in the carboxyl terminal tail of Cx43 was identified to be responsible for the association. A variant of Cx43 lacking this region was expressed only in a nonphosphorylated form and appeared to lose the capacity to localize to the region of cell-cell contact and dye transfer activity. When the expression of CIP150 was suppressed using small interfering RNA, the localization to the plasma membrane as well as dye transfer activity of Cx43 was significantly reduced. These results suggest that the newly identified domain is essential for the proper phosphorylation and localization of Cx43, and CIP150 is a novel partner protein targeting this domain.
Akiyama
Motofusa
M
Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0129, Japan.
Ishida
Norihiro
N
Ogawa
Takuya
T
Yogo
Keiichiro
K
Takeya
Tatsuo
T
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D019556:COS Cells; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism*; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D018031:Connexin 43 / Q000737:chemistry* / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism
D002352:Carrier Proteins; D018031:Connexin 43; D020662:Guanine Nucleotide Exchange Factors; D008565:Membrane Proteins; C505231:RIC1 protein, human; D011994:Recombinant Proteins