Cloning and characterization of a novel variant (mM-rdgBbeta1) of mouse M-rdgBs, mammalian homologs of Drosophila retinal degeneration B gene proteins, and its mRNA localization in mouse brain in comparison with other M-rdgBs.
We report the cloning, characterization and localization in the brain of a novel isoform termed mM-rdgBbeta1 (mouse type of mammalian retinal degeneration Bbeta1 protein) in comparison with the localization of three known mammalian homologs (M-rdgBbeta, M-rdgB1, M-rdgB2). mM-rdgBbeta1 cDNA contains a sequence of 119 bp as a form of insertion in the open reading frame of the known mM-rdgBbeta, and encodes a protein of 269 amino acids with a calculated molecular mass of 31.7 kDa, different from the molecular mass of 38.3 kDa of mM-rdgBbeta. It also contains a phosphatidylinositol transfer protein (PITP)-like domain similar to the known three homologs, as well as D-rdgB. The recombinant mM-rdgBbeta1 protein shows the specific binding activity to phosphatidylinositol but not to other phospholipids. This novel molecule is localized not only in the cytoplasm but also in the nucleus, different from the cytoplasmic localization of mM-rdgBbeta. In in situ hybridization analysis, the gene expression for mM-rdgBbeta1 in the brain, though weak, is rather confined to the embryonic stage, different from wider expression of mM-rdgBbeta in the gray matters of pre- and post-natal brains. Taken together, mM-rdgBbeta1 is suggested to play a role in the phosphoinositide-mediated signaling in the neural development.
Takano
Nobuo
N
Division of Histology, Department of Cell Biology, Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
Owada
Yuji
Y
Suzuki
Ryoji
R
Sakagami
Hiroyuki
H
Shimosegawa
Tooru
T
Kondo
Hisatake
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D002135:Calcium-Binding Proteins; D002352:Carrier Proteins / Q000096:biosynthesis / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics; D005136:Eye Proteins / Q000096:biosynthesis / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D008565:Membrane Proteins / Q000235:genetics*; D026901:Membrane Transport Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009928:Organ Specificity; D016716:PC12 Cells; D010716:Phosphatidylinositols / Q000378:metabolism; D049294:Phospholipid Transfer Proteins; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D002135:Calcium-Binding Proteins; D002352:Carrier Proteins; D018076:DNA, Complementary; D029721:Drosophila Proteins; D005136:Eye Proteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C107847:PITPNC1 protein, human; D010716:Phosphatidylinositols; D049294:Phospholipid Transfer Proteins; C471665:Pitpnm1 protein, mouse; C121270:Pitpnm2 protein, mouse; D020033:Protein Isoforms; D012333:RNA, Messenger; C068848:rdgB protein, Drosophila